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Le Doare K, Gaylord MA, Anderson AS, Andrews N, Baker CJ, Bolcen S, Felek A, Giardina PC, Grube CD, Hall T, Hallis B, Izu A, Madhi SA, Maniatis P, Matheson M, Mawas F, McKeen A, Rhodes J, Alston B, Patel P, Schrag S, Simon R, Tan CY, Taylor S, Kwatra G, Gorringe A. Interlaboratory comparison of a multiplex immunoassay that measures human serum IgG antibodies against six-group B streptococcus polysaccharides. Hum Vaccin Immunother 2024; 20:2330138. [PMID: 38608170 PMCID: PMC11018077 DOI: 10.1080/21645515.2024.2330138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/09/2024] [Indexed: 04/14/2024] Open
Abstract
Measurement of IgG antibodies against group B streptococcus (GBS) capsular polysaccharide (CPS) by use of a standardized and internationally accepted multiplex immunoassay is important for the evaluation of candidate maternal GBS vaccines in order to compare results across studies. A standardized assay is also required if serocorrelates of protection against invasive GBS disease are to be established in infant sera for the six predominant GBS serotypes since it would permit the comparison of results across the six serotypes. We undertook an interlaboratory study across five laboratories that used standardized assay reagents and protocols with a panel of 44 human sera to measure IgG antibodies against GBS CPS serotypes Ia, Ib, II, III, IV, and V. The within-laboratory intermediate precision, which included factors like the lot of coated beads, laboratory analyst, and day, was generally below 20% relative standard deviation (RSD) for all six serotypes, across all five laboratories. The cross-laboratory reproducibility was < 25% RSD for all six serotypes, which demonstrated the consistency of results across the different laboratories. Additionally, anti-CPS IgG concentrations for the 44-member human serum panel were established. The results of this study showed assay robustness and that the resultant anti-CPS IgG concentrations were reproducible across laboratories for the six GBS CPS serotypes when the standardized assay was used.
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Affiliation(s)
- Kirsty Le Doare
- Centre for Neonatal and Paediatric Infection, Institute for Infection and Immunity, St George’s, University of London, London, UK
- Makerere University Johns Hopkins University, Kampala, Uganda
- UK Health Security Agency, Porton Down, UK
| | | | | | - Nick Andrews
- Immunisation and Vaccine Preventable Diseases Division, United Kingdom Health Security Agency (UKHSA), London, UK
| | - Carol J. Baker
- Department of Pediatrics, Division of Infectious Disease, McGovern Medical School and UT Health, Houston, TX, USA
| | - Shanna Bolcen
- The Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Arif Felek
- Vaccine Division, Scientific Research & Innovation Group, MHRA, Potters Bar, UK
| | | | | | - Tom Hall
- Centre for Neonatal and Paediatric Infection, Institute for Infection and Immunity, St George’s, University of London, London, UK
| | | | - Alane Izu
- South African Medical Research Council: Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Department of Science/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa
| | - Shabir A. Madhi
- South African Medical Research Council: Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Department of Science/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa
| | - Pete Maniatis
- The Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | | | - Fatme Mawas
- Vaccine Division, Scientific Research & Innovation Group, MHRA, Potters Bar, UK
| | - Andrew McKeen
- Pfizer Global Biometrics & Data Management, Pearl River, NY, USA
| | - Julia Rhodes
- The Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | | | - Palak Patel
- The Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Stephanie Schrag
- The Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Raphael Simon
- Pfizer Vaccine Research & Development, Pearl River, NY, USA
| | - Charles Y. Tan
- Pfizer Global Biometrics & Data Management, Pearl River, NY, USA
| | | | - Gaurav Kwatra
- South African Medical Research Council: Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Department of Science/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa
- Department of Clinical Microbiology, Christian Medical College, Vellore, India
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Gaylord MA, Larrier M, Giordano-Schmidt D, Grube CD, Singh S, Nguyen HH, McKeen A, Tan CY, Anderson AS, Kalina WV, Pavliakova D, Giardina PC. Development and validation of a 6-plex Luminex-based assay for measuring human serum antibodies to group B streptococcus capsular polysaccharides. Hum Vaccin Immunother 2024; 20:2311480. [PMID: 38608171 PMCID: PMC11018021 DOI: 10.1080/21645515.2024.2311480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 01/25/2024] [Indexed: 04/14/2024] Open
Abstract
Six serotypes (Ia, Ib, II, III, IV, and V) cause nearly all group B streptococcal (GBS) disease globally. Capsular polysaccharide (CPS) conjugate vaccines aim to prevent GBS disease, however, licensure of a vaccine would depend on a standardized serological assay for measuring anti-CPS IgG responses. A multiplex direct Luminex-based immunoassay (dLIA) has been developed to simultaneously measure the concentration of serum IgG specific for the six prevalent GBS CPS serotypes. Assay validation was performed using serum samples obtained from human subjects vaccinated with an investigational 6-valent GBS CPS conjugate vaccine. Results for the assay are expressed as IgG concentrations (µg/mL) using a human serum reference standard composed of pooled sera from vaccinated subjects. The lower limits of quantitation (LLOQ) for all serotypes covered in the 6-plex GBS IgG dLIA fell within the range of 0.002-0.022 µg/mL IgG. Taken together, the 6-plex GBS IgG dLIA platform is specific for the six GBS serotypes included in Pfizer's investigational vaccine, has a wide dilution adjusted assay range, and is precise (<18.5% relative standard deviation) for all serotypes, and, therefore, is suitable for quantitatively measuring vaccine-induced or naturally acquired serotype-specific anti-CPS IgG responses against GBS.
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Affiliation(s)
| | - Melissa Larrier
- Vaccine Research and Development, Pfizer Inc, Pearl River, New York, USA
| | | | | | - Suddham Singh
- Vaccine Research and Development, Pfizer Inc, Pearl River, New York, USA
| | - Ha H. Nguyen
- Global Biometrics & Data Management, Pfizer Inc, Pearl River, New York, USA
| | - Andrew McKeen
- Global Biometrics & Data Management, Pfizer Inc, Pearl River, New York, USA
| | - Charles Y. Tan
- Global Biometrics & Data Management, Pfizer Inc, Collegeville, PA, USA
| | | | - Warren V. Kalina
- Vaccine Research and Development, Pfizer Inc, Pearl River, New York, USA
| | - Danka Pavliakova
- Vaccine Research and Development, Pfizer Inc, Pearl River, New York, USA
| | - Peter C. Giardina
- Vaccine Research and Development, Pfizer Inc, Pearl River, New York, USA
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Saukkoriipi A, Silmon de Monerri NC, Toropainen M, Lindholm L, Veijola R, Toppari J, Knip M, Radley D, Gomme E, Jongihlati B, Anderson AS, Palmu AA, Simon R. Association between anti-capsular IgG levels at birth and risk of invasive group B streptococcus disease in Finnish newborns: a retrospective case-control study. THE LANCET. MICROBE 2024; 5:689-696. [PMID: 38679040 DOI: 10.1016/s2666-5247(24)00038-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 05/01/2024]
Abstract
BACKGROUND Group B streptococcus is a major cause of neonatal disease. Natural history studies have linked maternally transferred anti-group B streptococcus capsular polysaccharide antibodies with protection against infant group B streptococcus disease. Previous studies of capsular polysaccharide antibody concentration in European populations have used maternal (not infant) sera and a non-standardised assay. This study aimed to evaluate anti-capsular polysaccharide IgG concentrations associated with protection against invasive group B streptococcus disease in Finnish infants. METHODS In this retrospective case-control study, we used cord sera from the Finnish DIPP study repository, which was obtained between Jan 1, 1995, and Dec 31, 2017. We included infants aged 6 months or younger with group B streptococcus infection (cases) and healthy infants (controls). We enrolled infants with invasive neonatal group B streptococcus (55 cases) and matched controls (229 controls) aged 6 months or younger after identification from Finnish health registers. We measured anti-capsular polysaccharide IgG (serotypes Ia-V) concentration using a standardised immunoassay and we estimated its relationship to disease risk using a Bayesian model. We used the derived risk-concentration curve to predict potential efficacy of six-valent group B streptococcus capsular polysaccharide vaccine (GBS6) based on previously reported immunogenicity data. FINDINGS Most (32 [58%] of 55 cases) group B streptococcus cases were due to serotype III and anti-serotype III streptococcus capsular IgG concentrations were higher in serotype III-matched controls than in cases (p<0·001). 0·120-0·266 μg/mL serotype III-specific IgG was estimated to confer 75-90% risk reduction against serotype III disease. A universal risk-concentration curve, aggregating results across all six serotypes, yielded similar results. Application of this curve to GBS6 immunogenicity data predicted maternal immunisation to be more than 80% efficacious for prevention of infant group B streptococcus disease. INTERPRETATION Higher neonatal anti-capsular polysaccharide serum IgG concentration at birth correlated with reduced risk of infant group B streptococcus disease in Finland. Based on these results, a maternal group B streptococcus capsular conjugate vaccine currently in development is predicted to be efficacious. FUNDING Pfizer.
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Affiliation(s)
| | | | | | - Laura Lindholm
- Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Riitta Veijola
- Department of Pediatrics, Research Unit of Clinical Medicine, Medical Research Center, University of Oulu, Oulu, Finland; Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland
| | - Jorma Toppari
- Institute of Biomedicine, Research Centre for Integrated Physiology and Pharmacology, Centre for Population Health Research, University of Turku, Turku, Finland; Department of Pediatrics, Turku University Hospital, Turku, Finland
| | - Mikael Knip
- Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Pediatric Research Center, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - David Radley
- Vaccine Research and Development, Pfizer, Pearl River, NY, USA
| | - Emily Gomme
- Vaccine Research and Development, Pfizer, Pearl River, NY, USA
| | | | | | - Arto A Palmu
- Finnish Institute for Health and Welfare, Tampere, Finland
| | - Raphael Simon
- Vaccine Research and Development, Pfizer, Pearl River, NY, USA.
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Karampatsas K, Hall T, Voysey M, Carreras-Abad C, Cochet M, Ramkhelawon L, Peregrine E, Andrews N, Heath PT, Le Doare K. Antibody kinetics between birth and three months of life in healthy infants with natural exposure to Group B streptococcus: A UK cohort study. Vaccine 2024; 42:3230-3238. [PMID: 38627147 DOI: 10.1016/j.vaccine.2024.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 03/11/2024] [Accepted: 04/04/2024] [Indexed: 04/29/2024]
Abstract
INTRODUCTION Capsular polysaccharide (CPS) serotype-specific Immunoglobulin G (IgG) in cord blood has been proposed as a correlate of protection against invasive Group B Streptococcus (iGBS) disease. Although protective levels are required in infants throughout the window of vulnerability up to 3 months of age, little is known regarding the kinetics of GBS-specific IgG over this period. METHODS We enrolled 33 healthy infants born to mothers colonized with GBS. We collected cord blood and infant blood samples either at one (21-35 days), two (49-63 days), or three months of age (77-91 days). We measured GBS serotype-specific CPS IgG concentrations and calculated the decay rate using a mixed-effects model. We further explored whether the antibody kinetics were affected by common maternal and infant factors and estimated the correlation between IgG concentration at birth and one, two, and three months of age. RESULTS The half-life estimate of IgG concentration for homologous and non-homologous GBS serotypes in paired samples with detectable IgG levels at both time points was 27.4 (95 % CI: 23.5-32.9) days. The decay rate did not vary by maternal age (p = 0.7), ethnicity (p = 0.1), gravida (p = 0.1), gestation (p = 0.7), and infant sex (p = 0.1). Predicted IgG titres above the assay lower limit of quantification on day 30 strongly correlated with titres at birth (Spearman correlation coefficient 0.71 [95 % CI: 0.60-0.80]). CONCLUSION Our results provide a basis for future investigations into the use of antibody kinetics in defining a serocorrelate of protection against late-onset iGBS disease.
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Affiliation(s)
- Konstantinos Karampatsas
- Centre for Neonatal and Paediatric Infection, St. George's, University of London, London, United Kingdom.
| | - Tom Hall
- Centre for Neonatal and Paediatric Infection, St. George's, University of London, London, United Kingdom
| | - Merryn Voysey
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Clara Carreras-Abad
- Centre for Neonatal and Paediatric Infection, St. George's, University of London, London, United Kingdom
| | - Madeleine Cochet
- Centre for Neonatal and Paediatric Infection, St. George's, University of London, London, United Kingdom
| | - Laxmee Ramkhelawon
- Centre for Neonatal and Paediatric Infection, St. George's, University of London, London, United Kingdom
| | - Elisabeth Peregrine
- Department of Obstetrics and Gynaecology, Kingston Hospital NHS Foundation Trust, London, United Kingdom
| | - Nick Andrews
- UK Health Security Agency, London, United Kingdom
| | - Paul T Heath
- Centre for Neonatal and Paediatric Infection, St. George's, University of London, London, United Kingdom
| | - Kirsty Le Doare
- Centre for Neonatal and Paediatric Infection, St. George's, University of London, London, United Kingdom; Pathogen Immunology Group, UK Health Security Agency, Porton Down, United Kingdom; Makerere University Johns Hopkins University, Kampala, Uganda
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Bjerkhaug AU, Ramalingham S, Mboizi R, Le Doare K, Klingenberg C. The immunogenicity and safety of Group B Streptococcal maternal vaccines: A systematic review. Vaccine 2024; 42:84-98. [PMID: 38072754 DOI: 10.1016/j.vaccine.2023.11.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 11/22/2023] [Accepted: 11/27/2023] [Indexed: 01/01/2024]
Abstract
PURPOSE To systematically review immunogenicity and safety data of maternal group B streptococcal (GBS) vaccines in published clinical trials until July 2023. METHODS EMBASE, MEDLINE, Cochrane Library and clinicaltrial.gov. databases were searched for clinical studies that reported immunogenicity and/or safety of GBS vaccine in non-pregnant adults, pregnant women and infants between 1st of January 1996 to 31st of July 2023. Pairs of reviewers independently selected, data extracted, and assessed the risk of bias of the studies. Discrepancies were resolved by consensus. (PROSPERO CRD42020185213). RESULTS We retrieved 1472 records from the literature search; 20 studies and 6 sub-studies were included, involving 4440 non-pregnant participants and 1325 pregnant women with their newborns. There was a significantly higher IgG Geometric Mean Concentration (GMC) and IgG placental transfer ratios in vaccinated compared to placebo groups, with peak response 4-8 weeks after vaccination. Placental transfer ratio varied from 0.4 to 1.4 across five studies. The different clinical trials used different assays that limited direct comparison. There were no significant differences in the risk of serious adverse events (adjusted OR 0.73; 95 % CI 0.49-1.07), serious adverse events leading to withdrawal (adjusted OR 0.44; 95 % CI 0.13-1.51), and systemic illness or fever (adjusted OR 1.05; 95 % CI 0.26-4.19) between the vaccine and placebo groups. CONCLUSIONS The published clinical trials show significant IgG GMC response in subjects receiving the conjugated capsular polysaccharide and surface subunit protein vaccines compared to placebo. In current clinical trials of experimental GBS maternal vaccines, there have been no observed serious adverse events of special interest directly linked to vaccination.
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Affiliation(s)
- Aline U Bjerkhaug
- Paediatric Research Group, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway; Department of Paediatrics and Adolescence Medicine, University Hospital of North Norway, Tromsø, Norway.
| | - Shouwmika Ramalingham
- Paediatric Research Group, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Robert Mboizi
- Makerere University Johns Hopkins University (MU-JHU) Research Collaboration (MUJHU CARE LTD), Kampala, Uganda
| | - Kirsty Le Doare
- Makerere University Johns Hopkins University (MU-JHU) Research Collaboration (MUJHU CARE LTD), Kampala, Uganda; Centre for Neonatal and Paediatric Infection, Maternal and Neonatal Vaccine Immunology Research Group, St Georgés University of London, United Kingdom
| | - Claus Klingenberg
- Paediatric Research Group, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway; Department of Paediatrics and Adolescence Medicine, University Hospital of North Norway, Tromsø, Norway
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Madhi SA, Anderson AS, Absalon J, Radley D, Simon R, Jongihlati B, Strehlau R, van Niekerk AM, Izu A, Naidoo N, Kwatra G, Ramsamy Y, Said M, Jones S, Jose L, Fairlie L, Barnabas SL, Newton R, Munson S, Jefferies Z, Pavliakova D, Silmon de Monerri NC, Gomme E, Perez JL, Scott DA, Gruber WC, Jansen KU. Potential for Maternally Administered Vaccine for Infant Group B Streptococcus. N Engl J Med 2023; 389:215-227. [PMID: 37467497 DOI: 10.1056/nejmoa2116045] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
BACKGROUND Natural history studies have correlated serotype-specific anti-capsular polysaccharide (CPS) IgG in newborns with a reduced risk of group B streptococcal disease. A hexavalent CPS-cross-reactive material 197 glycoconjugate vaccine (GBS6) is being developed as a maternal vaccine to prevent invasive group B streptococcus in young infants. METHODS In an ongoing phase 2, placebo-controlled trial involving pregnant women, we assessed the safety and immunogenicity of a single dose of various GBS6 formulations and analyzed maternally transferred anti-CPS antibodies. In a parallel seroepidemiologic study that was conducted in the same population, we assessed serotype-specific anti-CPS IgG concentrations that were associated with a reduced risk of invasive disease among newborns through 89 days of age to define putative protective thresholds. RESULTS Naturally acquired anti-CPS IgG concentrations were associated with a reduced risk of disease among infants in the seroepidemiologic study. IgG thresholds that were determined to be associated with 75 to 95% reductions in the risk of disease were 0.184 to 0.827 μg per milliliter. No GBS6-associated safety signals were observed among the mothers or infants. The incidence of adverse events and of serious adverse events were similar across the trial groups for both mothers and infants; more local reactions were observed in the groups that received GBS6 containing aluminum phosphate. Among the infants, the most common serious adverse events were minor congenital anomalies (umbilical hernia and congenital dermal melanocytosis). GBS6 induced maternal antibody responses to all serotypes, with maternal-to-infant antibody ratios of approximately 0.4 to 1.3, depending on the dose. The percentage of infants with anti-CPS IgG concentrations above 0.184 μg per milliliter varied according to serotype and formulation, with 57 to 97% of the infants having a seroresponse to the most immunogenic formulation. CONCLUSIONS GBS6 elicited anti-CPS antibodies against group B streptococcus in pregnant women that were transferred to infants at levels associated with a reduced risk of invasive group B streptococcal disease. (Funded by Pfizer and the Bill and Melinda Gates Foundation; C1091002 ClinicalTrials.gov number, NCT03765073.).
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Affiliation(s)
- Shabir A Madhi
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Annaliesa S Anderson
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Judith Absalon
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - David Radley
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Raphael Simon
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Babalwa Jongihlati
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Renate Strehlau
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Anika M van Niekerk
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Alane Izu
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Niree Naidoo
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Gaurav Kwatra
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Yogandree Ramsamy
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Mohamed Said
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Stephanie Jones
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Lisa Jose
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Lee Fairlie
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Shaun L Barnabas
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Ryan Newton
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Samantha Munson
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Zahra Jefferies
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Danka Pavliakova
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Natalie C Silmon de Monerri
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Emily Gomme
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - John L Perez
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Daniel A Scott
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - William C Gruber
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
| | - Kathrin U Jansen
- From the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (S.A.M., R. Strehlau, A.I., G.K., S.J., L.J.), the Department of Paediatrics and Child Health, Faculty of Health Sciences, Rahima Moosa Mother and Child Hospital (R. Strehlau), and Wits RHI, Faculty of Health Sciences, University of the Witwatersrand (L.F.), Johannesburg, the Division of Neonatal Medicine, School of Child and Adolescent Health, Faculty of Health Sciences, University of Cape Town, and Mowbray Maternity Hospital, Cape Town (A.M.N.), the Clinical Neonatology Unit, Prince Mshiyeni Memorial Hospital (N.N.), and the Department of Medical Microbiology, National Health Laboratory Services, Prince Mshiyeni Memorial Hospital and College of Health Sciences, University of KwaZulu-Natal (Y.R.), Durban, the University of Pretoria and the Tshwane Academic Division, National Health Laboratory Services, Pretoria (M.S.), and the Family Center for Research with Ubuntu, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch (S.L.B.) - all in South Africa; and Vaccine Research and Development, Pfizer, Pearl River, NY (A.S.A., J.A., D.R., R. Simon, B.J., R.N., S.M., Z.J., D.P., N.C.S.M., E.G., J.L.P., D.A.S., W.C.G., K.U.J.)
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7
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Esadze A, Grube CD, Wellnitz S, Singh S, Nguyen HH, Gaylord MA, Zhu A, Gribenko A, Tan CY, Anderson AS, Simon R. Calibration of a serum reference standard for Group B streptococcal polysaccharide conjugate vaccine development using surface plasmon resonance. NPJ Vaccines 2023; 8:71. [PMID: 37208375 DOI: 10.1038/s41541-023-00667-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 04/25/2023] [Indexed: 05/21/2023] Open
Abstract
Group B streptococcus (GBS) is a leading cause of neonatal morbidity and mortality worldwide. Development of a maternal vaccine to protect newborns through placentally transferred antibody is considered feasible based on the well-established relationship between anti-GBS capsular polysaccharide (CPS) IgG levels at birth and reduced risk of neonatal invasive GBS. An accurately calibrated serum reference standard that can be used to measure anti-CPS concentrations is critical for estimation of protective antibody levels across serotypes and potential vaccine performance. For this, precise weight-based measurement of anti-CPS IgG in sera is required. Here, we report an improved approach for determining serum anti-CPS IgG levels using surface plasmon resonance with monoclonal antibody standards, coupled with a direct Luminex-based immunoassay. This technique was used to quantify serotype-specific anti-CPS IgG levels in a human serum reference pool derived from subjects immunized with an investigational six-valent GBS glycoconjugate vaccine.
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Affiliation(s)
- Alexandre Esadze
- Pfizer Vaccine Research and Development, Pearl River, NY, 10965, USA
| | | | - Sabine Wellnitz
- Pfizer Vaccine Research and Development, Pearl River, NY, 10965, USA
| | - Suddham Singh
- Pfizer Vaccine Research and Development, Pearl River, NY, 10965, USA
| | - Ha H Nguyen
- Pfizer Worldwide Research and Development, Pearl River, NY, 10965, USA
| | | | - Aiping Zhu
- Pfizer Vaccine Research and Development, Pearl River, NY, 10965, USA
| | - Alexey Gribenko
- Pfizer Vaccine Research and Development, Pearl River, NY, 10965, USA
| | - Charles Y Tan
- Pfizer Worldwide Research and Development, Collegeville, PA, 19426, USA
| | | | - Raphael Simon
- Pfizer Vaccine Research and Development, Pearl River, NY, 10965, USA.
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8
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Absalon J, Simon R, Radley D, Giardina PC, Koury K, Jansen KU, Anderson AS. Advances towards licensure of a maternal vaccine for the prevention of invasive group B streptococcus disease in infants: a discussion of different approaches. Hum Vaccin Immunother 2022; 18:2037350. [PMID: 35240933 PMCID: PMC9009955 DOI: 10.1080/21645515.2022.2037350] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Group B streptococcus (Streptococcus agalactiae, GBS) is an important cause of life-threatening disease in newborns. Pregnant women colonized with GBS can transmit the bacteria to the developing fetus, as well as to their neonates during or after delivery where infection can lead to sepsis, meningitis, pneumonia, or/and death. While intrapartum antibiotic prophylaxis (IAP) is the standard of care for prevention of invasive GBS disease in some countries, even in such settings a substantial residual burden of disease remains. A GBS vaccine administered during pregnancy could potentially address this important unmet medical need and provide an adjunct or alternative to IAP for the prevention of invasive GBS disease in neonates. A hurdle for vaccine development has been relatively low disease rates making efficacy studies difficult. Given the well-accepted inverse relationship between anti-GBS capsular polysaccharide antibody titers at birth and risk of disease, licensure using serological criteria as a surrogate biomarker represents a promising approach to accelerate the availability of a GBS vaccine.
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Affiliation(s)
- Judith Absalon
- Pfizer Vaccine Research & Development, Pearl River, NY, USA
| | - Raphael Simon
- Pfizer Vaccine Research & Development, Pearl River, NY, USA
| | - David Radley
- Pfizer Vaccine Research & Development, Pearl River, NY, USA
| | | | - Kenneth Koury
- Pfizer Vaccine Research & Development, Pearl River, NY, USA
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9
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Gilbert PB, Isbrucker R, Andrews N, Goldblatt D, Heath PT, Izu A, Madhi SA, Moulton L, Schrag SJ, Shang N, Siber G, Sobanjo-Ter Meulen A. Methodology for a correlate of protection for group B Streptococcus: Report from the Bill & Melinda Gates Foundation workshop held on 10 and 11 February 2021. Vaccine 2022; 40:4283-4291. [PMID: 35779963 DOI: 10.1016/j.vaccine.2022.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/05/2022] [Indexed: 01/19/2023]
Abstract
Worldwide, childhood mortality has declined significantly, with improvements in hygiene and vaccinations against common childhood illnesses, yet newborn mortality remains high. Group B Streptococcus (GBS) disease significantly contributes to newborn mortality and is the leading cause of meningitis in infants. Many years of research have demonstrated the potential for maternal vaccination against GBS to confer protection to the infant, and at least three vaccine candidates are currently undergoing clinical trials. Given the relatively low disease incidence, any clinical vaccine efficacy study would need to include at least 40,000 to 60,000 participants. Therefore, a path to vaccine licensure based on a correlate of protection (CoP) would be the preferred route, with post-approval effectiveness studies demonstrating vaccine impact on reduction of disease burden likely to be required as part of conditional marketing approval. This workshop, hosted by the Bill & Melinda Gates Foundation on 10 and 11 February 2021, discussed considerations and potential statistical methodologies for establishing a CoP for GBS disease. Consensus was reached that an antibody marker with global threshold predictive of a high level of vaccine protection would be most beneficial for licensure assessments. IgG binding antibody in cord blood would likely serve as the CoP, with additional studies needed to confirm a high correlation with functional antibody and to demonstrate comparable kinetics of natural versus vaccine-induced antibody. Common analyses of ongoing seroepidemiological studies include estimation of absolute and relative disease risk as a function of infant antibody concentration, with adjustment for confounders of the impact of antibody concentration on infant GBS disease including gestational age and maternal age. Estimation of an antibody concentration threshold indicative of high protection should build in margin for uncertainties from sources including unmeasured confounders, imperfect causal mediation, and variability in point and confidence interval estimates across regions and/or serotypes.
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Affiliation(s)
- Peter B Gilbert
- Vaccine and Infectious Disease and Public Health Sciences Divisions, Fred Hutchinson Cancer Research Center and Department of Biostatistics, University of Washington, USA
| | | | - Nick Andrews
- UK Health Security Agency, Colindale, London, UK
| | - David Goldblatt
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Paul T Heath
- Vaccine Institute, St George's, University of London, London, UK
| | - Alane Izu
- South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; African Leadership in Vaccinology Expertise, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Shabir A Madhi
- South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; African Leadership in Vaccinology Expertise, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Lawrence Moulton
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Stephanie J Schrag
- National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Nong Shang
- National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
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10
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Izu A, Kwatra G, Madhi SA, Rigat F. Estimation of invasive Group B Streptococcus disease risk in young infants from case-control serological studies. BMC Med Res Methodol 2022; 22:85. [PMID: 35350991 PMCID: PMC8961496 DOI: 10.1186/s12874-022-01529-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 01/20/2022] [Indexed: 11/12/2022] Open
Abstract
Background Group B Streptococcus (GBS) infections are a major cause of invasive disease (IGbsD) in young infants and cause miscarriage and stillbirths. Immunization of pregnant women against GBS in addition to intrapartum antibiotic prophylaxis could prevent disease. Establishing accurate serological markers of protection against IGbsD could enable use of efficient clinical trial designs for vaccine development and licensure, without needing to undertake efficacy trials in prohibitively large number of mother-infant dyads. The association of maternal naturally acquired serotype-specific anti-capsular antibodies (IgG) against serotype-specific IGbsD in their infants has been studied in case-control studies. The statistical models used so far to estimate IGbsD risk from these case-control studies assumed that the antibody concentrations measured sharing the same disease status are sampled from the same population, not allowing for differences between mothers colonised by GBS and mothers also potentially infected (e.g urinary tract infection or chorioamnionitis) by GBS during pregnancy. This distinction is relevant as infants born from infected mothers with occult medical illness may be exposed to GBS prior to the mother developing antibodies measured in maternal or infant sera. Methods Unsupervised mixture model averaging (MMA) is proposed and applied here to accurately estimate infant IGbsD risk from case-control study data in presence or absence of antibody concentration subgroups potentially associated to maternal GBS carriage or infection. MMA estimators are compared to non-parametric disease risk estimators in simulation studies and by analysis of two published GBS case-control studies. Results MMA provides more accurate relative risk estimates under a broad range of data simulation scenarios and more accurate absolute disease risk estimates when the proportion of IGbsD cases with high antibody levels is not ignorable. MMA estimates of the relative and absolute disease risk curves are more amenable to clinical interpretation compared to non-parametric estimates with no detectable overfitting of the data. Antibody concentration thresholds predictive of protection from infant IGbsD estimated by MMA from maternal and infant sera are consistent with non-parametric estimates. Conclusions MMA is a flexible and robust method for design, accurate analysis and clinical interpretation of case-control studies estimating relative and absolute IGbsD risk from antibody concentrations measured at or after birth.
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Affiliation(s)
- Alane Izu
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa. .,Department of Science and Innovation/National Research Foundation South African Research Chair Initiative in Vaccine Preventable Diseases Unit, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa.
| | - Gaurav Kwatra
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa.,Department of Science and Innovation/National Research Foundation South African Research Chair Initiative in Vaccine Preventable Diseases Unit, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa
| | - Shabir A Madhi
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa.,Department of Science and Innovation/National Research Foundation South African Research Chair Initiative in Vaccine Preventable Diseases Unit, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa
| | - Fabio Rigat
- Statistics and Decision Sciences, Janssen Pharmaceuticals R & D, High Wycombe, United Kingdom.
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11
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Dangor Z, Kwatra G, Izu A, Khan M, Lala SG, Madhi SA. Infant serotype specific anti-capsular immunoglobulin G antibody and risk of invasive group B Streptococcal disease. Vaccine 2021; 39:6813-6816. [PMID: 34688499 DOI: 10.1016/j.vaccine.2021.10.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 11/26/2022]
Abstract
Past studies have mainly investigated the association of serotype-specific capsular IgG in the mother and risk reduction of invasive Group B Streptococcus (GBS) in their young infants. The efficiency of transplacental transfer of IgG could be affected by multiple maternal factors. Hence, investigation of infant serum GBS anti-capsular IgG and risk reduction for invasive GBS disease may be more robust and generalizable. In a matched case-control study, infant serum serotype-specific capsular polysaccharide Ia and III IgG concentrations were analyzed in infants with invasive GBS cases and healthy controls born to women with recto-vaginal colonization by the homotypic serotype. Using Bayesian modeling, an antibody concentration of 2.5 µg/mL and 1 µg/mL predicted a 90% reduced risk of invasive disease for serotype Ia and III, respectively. These data contribute to the possible licensure of a GBS polysaccharide-protein conjugate vaccine, targeted at pregnant women, based on serological correlates of protection against invasive GBS disease.
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Affiliation(s)
- Ziyaad Dangor
- South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, South Africa; Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, South Africa.
| | - Gaurav Kwatra
- South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, South Africa; Department of Clinical Microbiology, Christian Medical College, Vellore, India
| | - Alane Izu
- South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, South Africa
| | - Mahtaab Khan
- Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, South Africa
| | - Sanjay G Lala
- Department of Paediatrics & Child Health, Faculty of Health Sciences, University of the Witwatersrand, South Africa
| | - Shabir A Madhi
- South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, South Africa; African Leadership in Vaccinology Expertise, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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12
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Development and Validation of Enzyme-Linked Immunosorbent Assay for Group B Streptococcal Polysaccharide Vaccine. Vaccines (Basel) 2021; 9:vaccines9060545. [PMID: 34064299 PMCID: PMC8224333 DOI: 10.3390/vaccines9060545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 11/20/2022] Open
Abstract
Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of neonatal sepsis and meningitis in infants. Limitations of prenatal GBS screening and intrapartum antibiotic prophylaxis render developing GBS vaccines a high priority. In this study, we developed an enzyme-linked immunosorbent assay (ELISA) for the practical and large-scale evaluation of GBS capsular polysaccharide (PS) vaccine immunogenicity against three main serotypes, Ia, III, and V. GBS-ELISA was developed and subsequently validated using a standardized curve-fitting four-parameter logistic method. Specificity was measured using adsorption of serum with homologous and heterologous PS. Homologous adsorption showed a ≥75% inhibition of all three serotypes, whereas with heterologous PS, IgG GBS-ELISA inhibited only ≤25% of serotypes III and V. However, with serotype Ia, IgG antibody levels decreased by >50%, even after adsorption with heterologous PS (III or V). In comparison, the inhibition opsonophagocytic killing assay (OPA) of serotypes Ia GBS exhibited a reduction in opsonophagocytic activity of only 20% and 1.1% for serotypes III and V GBS, respectively. The precision of the GBS-ELISA was assessed in five independent experiments using four serum samples. The coefficient of variation was <5% for all three serotypes. This standardized GBS-ELISA would be useful for GBS vaccine development and its evaluation.
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13
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Dangor Z, Khan M, Kwatra G, Izu A, Nakwa F, Ramdin T, Fredericks J, Lala SG, Madhi SA. The Association Between Breast Milk Group B Streptococcal Capsular Antibody Levels and Late-onset Disease in Young Infants. Clin Infect Dis 2021; 70:1110-1114. [PMID: 31056692 DOI: 10.1093/cid/ciz360] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 04/30/2019] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Animal-model studies have demonstrated less group B streptococcal (GBS) invasive disease and gastrointestinal colonization after enteral administration of serotype-specific capsular antibodies. There is, however, a paucity of information on the association of breast milk GBS serotype-specific capsular antibodies and risks for invasive disease in infants. The aim of this study was to explore the association between natural secretory immunoglobulin A (sIgA) capsular antibodies in breast milk and the occurrence of late-onset disease (LOD) in young infants. METHODS A matched case-control study was undertaken in infants <3 months of age in Johannesburg, South Africa. Breast milk samples were collected on cases and controls matched for gestational age, maternal age, and human immunodeficiency virus status at time of enrollment. Capsular serotype Ia, Ib, III, and V sIgA antibody concentrations were measured using the fluorescence-based micro-bead immunosorbent assay. RESULTS Breast milk samples were available for 31 LOD cases (8 serotype Ia and 23 serotype III), 21 recto-vaginally colonized matched controls (10 serotype Ia and 11 serotype III), and 84 serotype Ia and 105 serotype III noncolonized matched controls. Using a Bayesian model to estimate the probability of disease, there were 90% reductions in the risks of developing serotypes Ia and III LOD with sIgA concentrations ≥0.14 µg/mL and ≥2.52 µg/mL, respectively. CONCLUSIONS Breast milk sIgA capsular antibodies were associated with lower risks for LOD in young infants. The ability of GBS polysaccharide-protein conjugate vaccines currently under development to induce sIgA responses warrant investigation as potential mediators of protection against LOD.
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Affiliation(s)
- Ziyaad Dangor
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Johannesburg, South Africa.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Johannesburg, South Africa.,Department of Paediatrics, University of the Witwatersrand, Johannesburg, South Africa
| | - Mahtaab Khan
- Department of Paediatrics, University of the Witwatersrand, Johannesburg, South Africa
| | - Gaurav Kwatra
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Johannesburg, South Africa.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Johannesburg, South Africa
| | - Alane Izu
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Johannesburg, South Africa.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Johannesburg, South Africa
| | - Firdose Nakwa
- Department of Paediatrics, University of the Witwatersrand, Johannesburg, South Africa
| | - Tanusha Ramdin
- Department of Paediatrics, University of the Witwatersrand, Johannesburg, South Africa
| | - Joy Fredericks
- Department of Paediatrics, University of the Witwatersrand, Johannesburg, South Africa
| | - Sanjay G Lala
- Department of Paediatrics, University of the Witwatersrand, Johannesburg, South Africa.,Perinatal Human Immunodeficiency Virus Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Shabir A Madhi
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Johannesburg, South Africa.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Johannesburg, South Africa
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14
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Leroux-Roels G, Bebia Z, Maes C, Aerssens A, De Boever F, Grassano L, Buffi G, Margarit I, Karsten A, Cho S, Slobod K, Corsaro B, Henry O. Safety and Immunogenicity of a Second Dose of an Investigational Maternal Trivalent Group B Streptococcus Vaccine in Nonpregnant Women 4-6 Years After a First Dose: Results From a Phase 2 Trial. Clin Infect Dis 2021; 70:2570-2579. [PMID: 31394574 PMCID: PMC7286364 DOI: 10.1093/cid/ciz737] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 08/09/2019] [Indexed: 12/23/2022] Open
Abstract
Background Maternal immunization against group B streptococcus (GBS) could protect infants from invasive GBS disease. Additional doses in subsequent pregnancies may be needed. We evaluated the safety and immunogenicity of a second dose of an investigational trivalent CRM197-glycoconjugate GBS vaccine (targeting serotypes Ia/Ib/III), administered to nonpregnant women 4–6 years postdose 1. Methods Healthy women either previously vaccinated with 1 dose of trivalent GBS vaccine 4–6 years before enrollment (n = 53) or never GBS vaccinated (n = 27) received a single trivalent GBS vaccine injection. Adverse events (AEs) were recorded. Serotype-specific (Ia/Ib/III) anti-GBS antibodies were measured by multiplex immunoassay prevaccination and 30/60 days postvaccination. Results AEs were reported with similar rates after a first or second dose; none were serious. Of previously GBS-vaccinated women, 92%–98% had anti-GBS concentrations that exceeded an arbitrary threshold (8 µg/mL) for each serotype 60 days postdose 2 vs 36%–56% postdose 1 in previously non–GBS-vaccinated women. Of previously GBS-vaccinated women with undetectable baseline (predose 1) anti-GBS levels, 90%–98% reached this threshold postdose 2. For each serotype, anti-GBS geometric mean concentrations (GMCs) 30/60 days postdose 2 in previously GBS-vaccinated women were ≥200-fold higher than baseline GMCs. Among women with undetectable baseline anti-GBS levels, postdose 2 GMCs in previously GBS-vaccinated women exceeded postdose 1 GMCs in previously non–GBS-vaccinated women (≥7-fold). Conclusions A second trivalent GBS vaccine dose administered 4–6 years postdose 1 was immunogenic with a favorable safety profile. Women with undetectable preexisting anti-GBS concentrations may benefit from a sufficiently spaced second vaccine dose. Clinical Trials Registration NCT02690181
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Affiliation(s)
- Geert Leroux-Roels
- Center for Vaccinology, Ghent University and Ghent University Hospital, Belgium
| | | | - Cathy Maes
- Center for Vaccinology, Ghent University and Ghent University Hospital, Belgium
| | - Annelies Aerssens
- Center for Vaccinology, Ghent University and Ghent University Hospital, Belgium
| | - Fien De Boever
- Center for Vaccinology, Ghent University and Ghent University Hospital, Belgium
| | | | | | | | | | - Stephen Cho
- Novartis, Cambridge, Massachusetts.,GSK, Cambridge, Massachusetts
| | - Karen Slobod
- Novartis, Cambridge, Massachusetts.,GSK, Cambridge, Massachusetts
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15
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Madhi SA, Izu A, Kwatra G, Jones S, Dangor Z, Wadula J, Moultrie A, Adam Y, Pu W, Henry O, Briner C, Cutland CL. Association of Group B streptococcus serum serotype-specific anti-capsular IgG concentration and risk reduction for invasive Group B streptococcus disease in South African infants: an observational birth-cohort, matched case-control study. Clin Infect Dis 2020; 73:e1170-e1180. [PMID: 33341870 DOI: 10.1093/cid/ciaa1873] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Licensure of a Group B streptococcus (GBS) polysaccharide-protein conjugate vaccine for protecting infants against invasive GBS disease (IGbsD) will likely need to be based on demonstrating vaccine safety in pregnant women, and benchmarking immunogenicity against a serological threshold associated with risk reduction of IGbsD. We investigated the association between naturally-derived GBS serotype-Ia and III IgG and risk reduction of IGbsD in infants' ≤90 days of age. METHODS In a matched case-control study (ClinicalTrials.gov NCT02215226), IGbsD cases were identified from a cohort of 38,233 mother-newborn dyads. Mothers colonized vaginally with serotype-Ia or III at birth, and their healthy infants were eligible as matched controls. GBS serotype-specific anti-capsular IgG was measured on maternal and cord blood/infant sera by multiplex Luminex assay; and the IgG threshold associated with 90% risk reduction of IGbsD derived by estimating absolute disease risk. RESULTS In infants born ≥34 weeks gestational age, cord-blood IgG geometric mean concentrations (GMC) were lower in cases than controls for serotype-Ia (0.05 vs. 0.50µg/ml; p=0.004) and III (0.20 vs. 0.38µg/ml; p=0.078). Cord-blood IgG concentration ≥1.04 and ≥1.53µg/ml were associated with 90% risk reduction of serotype-Ia and III IGbsD, respectively. The maternal sera IgG threshold associated with 90% risk reduction was ≥2.31 and ≥3.41µg/ml for serotype-Ia and III, respectively. CONCLUSIONS The threshold associated with a reduced risk for serotype-Ia and III IGbsD identified on infant sera supports the case for licensure of a GBS polysaccharide-protein conjugate vaccine based on immunogenicity evaluation benchmarked against the defined thresholds.
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Affiliation(s)
- Shabir A Madhi
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science Johannesburg, South Africa.,Department of Science/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa
| | - Alane Izu
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science Johannesburg, South Africa.,Department of Science/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa
| | - Gaurav Kwatra
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science Johannesburg, South Africa.,Department of Science/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa
| | - Stephanie Jones
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science Johannesburg, South Africa.,Department of Science/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa
| | - Ziyaad Dangor
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science Johannesburg, South Africa.,Department of Science/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa.,Department of Paediatrics, Chris Hani Baragwanath Academic Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jeanette Wadula
- National Health Laboratory Services, Department of Anatomical Pathology, School of Pathology, University of the Witwatersrand, Faculty of Health Sciences, Johannesburg, South Africa
| | - Andrew Moultrie
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science Johannesburg, South Africa.,Department of Science/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa
| | - Yasmin Adam
- Department of Obstetrics and Gynecology, Chris Hani-Baragwanath Academic Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | | | - Carmen Briner
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science Johannesburg, South Africa.,Department of Science/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa
| | - Clare L Cutland
- South African Medical Research Council: Vaccines and Infectious Diseases Analytical Research Unit (VIDA), University of the Witwatersrand, Faculty of Health Science Johannesburg, South Africa.,Department of Science/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa
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16
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Singh T, Otero CE, Li K, Valencia SM, Nelson AN, Permar SR. Vaccines for Perinatal and Congenital Infections-How Close Are We? Front Pediatr 2020; 8:569. [PMID: 33384972 PMCID: PMC7769834 DOI: 10.3389/fped.2020.00569] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 08/04/2020] [Indexed: 12/26/2022] Open
Abstract
Congenital and perinatal infections are transmitted from mother to infant during pregnancy across the placenta or during delivery. These infections not only cause pregnancy complications and still birth, but also result in an array of pediatric morbidities caused by physical deformities, neurodevelopmental delays, and impaired vision, mobility and hearing. Due to the burden of these conditions, congenital and perinatal infections may result in lifelong disability and profoundly impact an individual's ability to live to their fullest capacity. While there are vaccines to prevent congenital and perinatal rubella, varicella, and hepatitis B infections, many more are currently in development at various stages of progress. The spectrum of our efforts to understand and address these infections includes observational studies of natural history of disease, epidemiological evaluation of risk factors, immunogen design, preclinical research of protective immunity in animal models, and evaluation of promising candidates in vaccine trials. In this review we summarize this progress in vaccine development research for Cytomegalovirus, Group B Streptococcus, Herpes simplex virus, Human Immunodeficiency Virus, Toxoplasma, Syphilis, and Zika virus congenital and perinatal infections. We then synthesize this evidence to examine how close we are to developing a vaccine for these infections, and highlight areas where research is still needed.
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Affiliation(s)
- Tulika Singh
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
| | - Claire E. Otero
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
| | - Katherine Li
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
| | - Sarah M. Valencia
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
| | - Ashley N. Nelson
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
| | - Sallie R. Permar
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
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17
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Kyohere M, Davies HG, Musoke P, Nakimuli A, Tusubira V, Tasimwa HB, Nsimire JS, Heath P, Cose S, Baker C, Le Doare K, Sekikubo M. Seroepidemiology of maternally-derived antibody against Group B Streptococcus (GBS) in Mulago/Kawempe Hospitals Uganda - PROGRESS GBS. Gates Open Res 2020; 4:155. [PMID: 33299966 PMCID: PMC7706450 DOI: 10.12688/gatesopenres.13183.2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2020] [Indexed: 01/31/2023] Open
Abstract
Background: Group B
Streptococcus (GBS) is a major contributor to the high burden of neonatal and young infant infectious disease in resource- limited settings. As disease protection during the first six months of life is provided via placental transfer of maternal antibodies, a maternal GBS vaccine may provide an effective strategy to reduce infectious death and disability. An efficacy study may be difficult because of the large sample size required and alternative approaches such as serocorrelates of protection based on natural antibody concentration are being considered. Such studies would need to be undertaken in high burden settings such as Uganda. We therefore aim to evaluate the feasibility and acceptability of a GBS sero-epidemiology study in Kampala, Uganda. Methods: This is a prospective cohort and nested case-control study, conducted across two-centres with two entry points. A) consecutive women and their infants at birth, with collection of maternal swab, cord and maternal blood, and follow up by telephone until the infant is 3 months old; B) any infant under 3 months of age, presenting with signs of sepsis to any of the paediatric units, with collection of blood culture, cerebrospinal fluid and nasopharyngeal swabs. Any infants identified as having GBS disease (defined as GBS isolated from a normally sterile site) will be recruited and followed up for two years to assess their neurodevelopment. A nested qualitative study will investigate stakeholder (pregnant women and their families, healthcare workers and community leaders) opinions of sampling for such a study and understanding and potential uptake of vaccines in pregnancy. Discussion: The primary aim is to determine anti-GBS antibody concentration in infants with GBS disease compared to healthy controls. Secondary outcomes include stillbirth and all-cause infection and acceptance of sample methods and vaccination. The findings will inform scalability and sustainability of the programme in Uganda.
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Affiliation(s)
- Mary Kyohere
- Makerere University - Johns Hopkins University (MUJHU) Research Collaboration, Kampala, Uganda
| | - Hannah Georgia Davies
- Paediatric Infection and Immunology Institute of Infection and Immunity, St George's, University of London, London, SW170RE, UK
| | - Philippa Musoke
- Makerere University - Johns Hopkins University (MUJHU) Research Collaboration, Kampala, Uganda.,Department of Paediatrics and Child Health, Makerere University, College of Health Sciences, Kampala, 256, Uganda
| | - Annettee Nakimuli
- Department of Obstetrics and Gynaecology,, Makerere University, College of Health Sciences, Kampala, 256, Uganda
| | - Valerie Tusubira
- Makerere University - Johns Hopkins University (MUJHU) Research Collaboration, Kampala, Uganda
| | - Hannington Baluku Tasimwa
- Department of Medical Microbiology, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | | | - Paul Heath
- Paediatric Infection and Immunology Institute of Infection and Immunity, St George's, University of London, London, SW170RE, UK
| | - Stephen Cose
- Immunology and Vaccines Research Unit, MRC/UVRI and LSHTM Uganda, Entebbe, Uganda
| | - Carol Baker
- University of Texas Health Science Center, McGovern Medical School, Houston, Texas, TX 77030, USA
| | - Kirsty Le Doare
- Paediatric Infection and Immunology Institute of Infection and Immunity, St George's, University of London, London, SW170RE, UK.,Immunology and Vaccines Research Unit, MRC/UVRI and LSHTM Uganda, Entebbe, Uganda
| | - Musa Sekikubo
- Department of Obstetrics and Gynaecology,, Makerere University, College of Health Sciences, Kampala, 256, Uganda
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18
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Kyohere M, Davies HG, Musoke P, Nakimuli A, Tusubira V, Tasimwa HB, Nsimire JS, Heath P, Cose S, Baker C, Le Doare K, Sekikubo M. Seroepidemiology of maternally-derived antibody against Group B Streptococcus (GBS) in Mulago/Kawempe Hospitals Uganda - PROGRESS GBS. Gates Open Res 2020; 4:155. [DOI: 10.12688/gatesopenres.13183.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2020] [Indexed: 11/20/2022] Open
Abstract
Background: Group B Streptococcus (GBS) is a major contributor to the high burden of neonatal and young infant infectious disease in resource- limited settings. As disease protection during the first six months of life is provided via placental transfer of maternal antibodies, a maternal GBS vaccine may provide an effective strategy to reduce infectious death and disability. An efficacy study may be difficult because of the large sample size required and alternative approaches such as serocorrelates of protection based on natural antibody concentration are being considered. Such studies would need to be undertaken in high burden settings such as Uganda. We therefore aim to evaluate the feasibility and acceptability of a GBS sero-epidemiology study in Kampala, Uganda. Methods: This is a prospective cohort and nested case-control study, conducted across two-centres with two entry points. A) consecutive women and their infants at birth, with collection of maternal swab, cord and maternal blood, and follow up by telephone until the infant is 3 months old; B) any infant under 3 months of age, presenting with signs of sepsis to any of the paediatric units, with collection of blood culture, cerebrospinal fluid and nasopharyngeal swabs. Any infants identified as having GBS disease (defined as GBS isolated from a normally sterile site) will be recruited and followed up for two years to assess their neurodevelopment. A nested qualitative study will investigate stakeholder (pregnant women and their families, healthcare workers and community leaders) opinions of sampling for such a study and understanding and potential uptake of vaccines in pregnancy. Discussion: The primary aim is to determine anti-GBS antibody concentration in infants with GBS disease compared to healthy controls. Secondary outcomes include stillbirth and all-cause infection and acceptance of sample methods and vaccination. The findings will inform scalability and sustainability of the programme in Uganda.
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19
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Absalon J, Segall N, Block SL, Center KJ, Scully IL, Giardina PC, Peterson J, Watson WJ, Gruber WC, Jansen KU, Peng Y, Munson S, Pavliakova D, Scott DA, Anderson AS. Safety and immunogenicity of a novel hexavalent group B streptococcus conjugate vaccine in healthy, non-pregnant adults: a phase 1/2, randomised, placebo-controlled, observer-blinded, dose-escalation trial. THE LANCET. INFECTIOUS DISEASES 2020; 21:263-274. [PMID: 32891191 DOI: 10.1016/s1473-3099(20)30478-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 03/13/2020] [Accepted: 04/23/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Group B streptococcus (GBS) is a major cause of invasive disease in young infants. Infants born to women with sufficient pre-existing anti-GBS capsular IgG antibodies are at reduced risk of GBS disease, making maternal immunisation a potential strategy for prevention. We aimed to assess the safety and immunogenicity of a novel hexavalent (serotypes Ia, Ib, II, III, IV, and V) GBS conjugate vaccine (GBS6). METHODS This phase 1/2, placebo-controlled, observer-blinded, dose-escalation trial, was done at four clinical research centres in the USA (Kentucky, Georgia, and two sites in Utah). Healthy, non-pregnant adults aged 18-49 years were randomly assigned using an interactive, web-based response technology system. Within each dose group (low, medium, or high), participants in sentinel cohorts were randomly assigned 2:2:1 and expanded cohort participants were randomly assigned 4:4:1 to receive GBS6 with aluminium phosphate (AlPO4), GBS6 without AlPO4, or placebo (saline control). One 0·5 mL dose of either saline placebo or 5 μg capsular polysaccharide per serotype in the low-dose group, 10 μg capsular polysaccharide per serotype in the medium-dose group, or 20 μg capsular polysaccharide per serotype in the high-dose group was administered by intramuscular injection into the deltoid muscle on day 1. The primary outcome was safety up to 6 months after vaccination, including the proportion of sentinel cohort participants with clinical laboratory abnormalities at 1 week, the proportion of all participants reporting solicited local reactions, systemic events, or use of antipyretic or pain medication within 14 days, adverse events up to 1 month, and medically attended or serious adverse events up to 6 months. The secondary outcome was GBS immunogenicity (serotype-specific IgG geometric mean concentrations at 1 month). This study is registered with ClinicalTrials.gov, NCT03170609. FINDINGS Between June 5, 2017, and June 25, 2018, 365 participants were randomly assigned and 364 (52 in each dose group) were vaccinated and included in the safety analysis. Unsolicited adverse events were reported by 15 (29%) participants in the 5 μg with AlPO4 group, 13 (25%) in the 5 μg without AlPO4 group, 22 (42%) in the 10 μg with AlPO4 group, 12 (23%) in the 10 μg without AlPO4 group, 25 (48%) in the 20 μg with AlPO4 group, 21 (40%) in the 20 μg without AlPO4 group, and 20 (38%) in the placebo group. The most common unsolicited adverse events were in the system organ class of infections and infestations in any dose or formulation of GBS6 (ranging from six [12%] in the 10 μg without AlPO4 group to 15 [29%] in the 20 μg with AlPO4 group and placebo group). Three participants reported at least one serious adverse event during the study, one each in the 5 μg GBS6 with AlPO4 group (diabetic ketoacidosis, two events; resolved), 10 μg GBS6 with AlPO4 group (died by suicide), and 20 μg GBS6 with AlPO4 group (metrorrhagia; resolved). None of these serious adverse events were considered related to the vaccine. 11 of the 365 participants were excluded from the evaluable immunogenicity population, including one participant who did not receive the vaccine, and ten who at 1 month after vaccination were withdrawn for various reasons. GBS serotype-specific IgG geometric mean concentrations increased by 1 week after vaccination for all GBS6 groups, peaked at 2 weeks, stabilised by 1 month, and declined gradually but remained higher than placebo at 6 months. INTERPRETATION GBS6 was well tolerated in healthy adults and elicited robust immune responses for all dose levels and formulations that persisted 6 months after vaccination. This study supports further evaluation of GBS6 in pregnant women. FUNDING Pfizer.
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Affiliation(s)
- Judith Absalon
- Vaccine Research and Development, Pfizer, Pearl River, NY, USA.
| | | | - Stan L Block
- Kentucky Pediatric/Adult Research, Bardstown, KY, USA
| | | | - Ingrid L Scully
- Vaccine Research and Development, Pfizer, Pearl River, NY, USA
| | | | | | - Wendy J Watson
- Vaccine Research and Development, Pfizer, Collegeville, PA, USA
| | | | | | - Yahong Peng
- Vaccine Research and Development, Pfizer, Collegeville, PA, USA
| | - Samantha Munson
- Vaccine Research and Development, Pfizer, Collegeville, PA, USA
| | | | - Daniel A Scott
- Vaccine Research and Development, Pfizer, Collegeville, PA, USA
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20
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Neurodevelopmental Impairment at 1 Year of Age in Infants With Previous Invasive Group B Streptococcal Sepsis and Meningitis. Pediatr Infect Dis J 2020; 39:794-798. [PMID: 32804460 DOI: 10.1097/inf.0000000000002695] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Invasive group B streptococcal (GBS) disease causes considerable morbidity and mortality in young infants, and 18% of GBS-meningitis survivors have moderate-to-severe neurodevelopmental impairment. However, there is a paucity of data regarding neurologic impairment following GBS sepsis. METHODS A case-control study was undertaken in infants at 3 secondary-tertiary hospitals in Johannesburg, South Africa. Neurodevelopmental assessments were done at 1 year of age using the Denver II Developmental screening tool. A case was defined as isolation of GBS from blood or cerebrospinal fluid in infants less than 90 days of age. Three healthy controls (range: 1-6) were matched to maternal age, maternal HIV-infection status, gestational age and timing of enrollment. RESULTS Of 122 invasive GBS cases, 78 (63.9%) had sepsis and 44 (36.1%) meningitis. Twenty-two (18%) invasive GBS cases (17 of 78; 21.8% with sepsis and 5 of 44; 11.4% with meningitis) died during the course of hospitalization, and a further 2 (1.6%; 1 sepsis and 1 meningitis case) died by 1 year of age. Five (1.1%) of 449 controls died by 1 year of age. Of the 45 GBS sepsis cases and 141 matched controls followed through to 1 year of age, 11 (24.4%) cases (3 with moderate-to-severe impairment) and 10 (7.1%) controls had an abnormal Denver score with an adjusted (for gender) odds ratio of 3.51; 95% confidence interval (CI): 1.23-10.04; P = 0.019. Four (20%) of the 20 GBS meningitis cases compared with 1 (1.5%) control had neurologic impairment at 1-year of age (aOR: 8.29; 95% CI: 0.88-78.3; P = 0.065) CONCLUSION:: In this setting, invasive GBS disease is associated with a high mortality. Infant survivors of invasive GBS sepsis compared with controls had 3.5-fold greater odds of neurologic impairment by 1 year of age. This corroborates the need for strategies to prevent invasive GBS disease.
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21
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Swamy GK, Metz TD, Edwards KM, Soper DE, Beigi RH, Campbell JD, Grassano L, Buffi G, Dreisbach A, Margarit I, Karsten A, Henry O, Lattanzi M, Bebia Z. Safety and immunogenicity of an investigational maternal trivalent group B streptococcus vaccine in pregnant women and their infants: Results from a randomized placebo-controlled phase II trial. Vaccine 2020; 38:6930-6940. [PMID: 32883555 DOI: 10.1016/j.vaccine.2020.08.056] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 01/31/2023]
Abstract
BACKGROUND This study evaluated the safety and immunogenicity of an investigational trivalent group B streptococcus (GBS) vaccine in US pregnant women, transplacental serotype-specific antibody transfer and persistence in infants, and serotype-specific antibodies in breast milk. METHODS This randomized, observer-blind, placebo-controlled trial administered one dose of trivalent GBS vaccine (n = 49) or placebo (n = 26) to healthy pregnant 18-40-year-old women at 240/7-346/7 weeks' gestation. Women were enrolled from March 2014 to August 2015. Safety follow-up continued through postpartum day 180. Primary immunogenicity objectives were to evaluate serotype Ia/Ib/III-specific immunoglobulin G (IgG) levels in sera from women on day 1 (pre-vaccination), day 31, delivery and postpartum days 42 and 90, and from infants at birth (cord blood), days 42 and 90. Antibody transfer ratios (cord blood/maternal sera at delivery) and serotype-specific secretory immunoglobulin A (sIgA) and IgG in breast milk after delivery and on postpartum days 42 and 90 were evaluated. The planned sample size was not based on statistical assumptions for this descriptive study. RESULTS Baseline characteristics were similar between groups. Serious adverse events were reported for 16% of GBS-vaccinated women and 15% of their infants, and 15% of placebo recipients and 12% of their infants; none were fatal or deemed vaccine-related. Serotype-specific IgG geometric mean concentrations (GMCs) were 13-23-fold higher in vaccine vs placebo recipients on day 31 and persisted until postpartum day 90. Median antibody concentrations were substantially higher in women with detectable pre-vaccination antibody concentrations. Antibody transfer ratios in the vaccine group were 0.62-0.82. Infant IgG GMCs and breast milk sIgA GMCs were higher in the vaccine vs the placebo group at all timepoints. CONCLUSIONS Maternal immunization with the trivalent GBS vaccine in US women had a favorable safety profile, elicited antibodies that were transplacentally transferred and persisted in infants for a minimum of 3 months. CLINICAL TRIAL REGISTRATION Clinicaltrials.gov, NCT02046148.
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Affiliation(s)
- Geeta K Swamy
- Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, NC, USA.
| | - Torri D Metz
- Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, CO, USA.
| | - Kathryn M Edwards
- Vanderbilt Vaccine Research Program, Vanderbilt University, Nashville, TN, USA.
| | - David E Soper
- Medical University of South Carolina, Charleston, SC, USA.
| | - Richard H Beigi
- UPMC Magee-Women's Hospital, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - James D Campbell
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA.
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22
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Le Doare K, Heath PT, Plumb J, Owen NA, Brocklehurst P, Chappell LC. Uncertainties in Screening and Prevention of Group B Streptococcus Disease. Clin Infect Dis 2020; 69:720-725. [PMID: 30561556 PMCID: PMC6669315 DOI: 10.1093/cid/ciy1069] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 12/11/2018] [Indexed: 01/29/2023] Open
Abstract
In autumn 2016, the UK Department of Health (now Department of Health and Social Care) convened 2 meetings to discuss how to address research evidence gaps in order to minimize the impact of infant group B streptococcus (GBS) disease in the United Kingdom. At that meeting, a number of research priorities were highlighted, including improving the screening for GBS colonization in pregnant women, offering intrapartum antibiotic prophylaxis and point-of-care testing, and understanding the effect of widespread intrapartum antibiotic use on long-term infant health. Further discussions involved investigating the feasibility of a large prospective study of pregnant women and their infants in order to understand the role of antibodies in the protection against GBS disease in infancy following maternal exposure to GBS colonization. Here, we summarize the research uncertainties identified at that meeting.
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Affiliation(s)
- Kirsty Le Doare
- Paediatric Infectious Disease Research Group & Vaccine Institute, St George's University of London, London, United Kingdom
| | - Paul T Heath
- Paediatric Infectious Disease Research Group & Vaccine Institute, St George's University of London, London, United Kingdom
| | - Jane Plumb
- Group B Strep Support, London, United Kingdom
| | - Natalie A Owen
- Science, Research and Evidence, Department of Health and Social Care, London, United Kingdom
| | - Peter Brocklehurst
- Birmingham Clinical Trials Unit, University of Birmingham, London, United Kingdom
| | - Lucy C Chappell
- Department of Obstetrics, King's College London, London, United Kingdom
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23
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Kobayashi M, Schrag SJ, Alderson MR, Madhi SA, Baker CJ, Sobanjo-Ter Meulen A, Kaslow DC, Smith PG, Moorthy VS, Vekemans J. WHO consultation on group B Streptococcus vaccine development: Report from a meeting held on 27-28 April 2016. Vaccine 2019; 37:7307-7314. [PMID: 28017431 PMCID: PMC6892266 DOI: 10.1016/j.vaccine.2016.12.029] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 10/17/2016] [Indexed: 11/29/2022]
Abstract
Globally, group B Streptococcus (GBS) remains a leading cause of sepsis and meningitis in infants in the first 90days of life. Intrapartum antibiotic prophylaxis (IAP) for women at increased risk of transmitting GBS to their newborns has been effective in reducing part, but not all, of the GBS disease burden in many high income countries (HICs). In low- and middle-income countries (LMICs), IAP use is low. Immunization of pregnant women with a GBS vaccine represents an alternative strategy to protecting newborns and young infants, through transplacental antibody transfer and potentially by reducing new vaginal colonization. This vaccination strategy was first suggested in the 1970s and several potential GBS vaccines have completed phase I/II clinical trials. During the 2015 WHO Product Development for Vaccines Advisory Committee meeting, GBS was identified as a high priority for the development of a vaccine for maternal immunization because of the major public health burden posed by GBS in LMICs, and the high technical feasibility for successful development. Following this meeting, the first WHO technical consultation on GBS vaccines was held on the 27th and 28th of April 2016, to consider development pathways for such vaccines, focused on their potential role in reducing newborn and young infant deaths and possibly stillbirths in LMICs. Discussion topics included: (1) pathophysiology of disease; (2) current gaps in the knowledge of global disease burden and serotype distribution; (3) vaccine candidates under development; (4) design considerations for phase III trials; and (5) pathways to licensure, policy recommendations and use. Efforts to address gaps identified in each of these areas are needed to establish the public health need for, the development and deployment of, efficacious GBS vaccines. In particular, more work is required to understand the global disease burden of GBS-associated stillbirths, and to develop quality-assured standardized antibody assays to identify correlates of protection.
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Affiliation(s)
- Miwako Kobayashi
- National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30329-4027, USA; Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Stephanie J Schrag
- National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30329-4027, USA
| | - Mark R Alderson
- Center for Vaccine Innovation and Access, PATH, Seattle, WA 98121, USA
| | - Shabir A Madhi
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, and Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Carol J Baker
- Department of Pediatrics, Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - David C Kaslow
- Center for Vaccine Innovation and Access, PATH, Seattle, WA 98121, USA
| | - Peter G Smith
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, UK
| | - Vasee S Moorthy
- Initiative for Vaccine Research, World Health Organization, CH-1211 Geneva 27, Switzerland
| | - Johan Vekemans
- Initiative for Vaccine Research, World Health Organization, CH-1211 Geneva 27, Switzerland.
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24
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Plotkin SA. Updates on immunologic correlates of vaccine-induced protection. Vaccine 2019; 38:2250-2257. [PMID: 31767462 DOI: 10.1016/j.vaccine.2019.10.046] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/15/2019] [Accepted: 10/17/2019] [Indexed: 02/06/2023]
Abstract
Correlates of protection (CoPs) are increasingly important in the development and licensure of vaccines. Although the study of CoPs was initially directed at identifying a single immune function that could explain vaccine efficacy, it has become increasingly clear that there are often multiple functions responsible for efficacy. This review is meant to supplement prior articles on the subject, illustrating both simple and complex CoPs.
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Affiliation(s)
- Stanley A Plotkin
- Emeritus Professor of Pediatrics, University of Pennsylvania, Vaxconsult, 4650 Wismer Rd., Doylestown, PA 18902, United States.
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25
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Abstract
Group B Streptococcus (GBS) is estimated to have caused 319,000 cases of neonatal disease resulting in 90,000 infant deaths globally in 2015. It is also associated with maternal sepsis, preterm births, stillbirths and neonatal encephalopathy. There is a significant burden of neurologic impairment among survivors of infant GBS disease. Intrapartum antibiotic prophylaxis strategies have reduced the incidence of newborn early-onset GBS (occurring days 0-6) in some settings, but they are not feasible in many low and middle-income countries. A maternal vaccine given to pregnant women to stimulate passive transplacental transfer of protective antibodies has the potential to reduce maternal disease, adverse pregnancy outcomes and newborn disease. Phase I and II vaccine studies are occurring, but conducting phase III efficacy studies of a GBS vaccine candidate would require very large numbers due to the relatively low incidence of invasive GBS disease. It has therefore been proposed that alternative pathways to vaccine licensure should be explored, for example, through use of a regulatory approved correlate of protection and safety evaluation in mothers, fetuses and infants. These studies would then be followed-up with post-licensure phase IV studies in which vaccine effectiveness is evaluated.
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26
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The role of immune correlates of protection on the pathway to licensure, policy decision and use of group B Streptococcus vaccines for maternal immunization: considerations from World Health Organization consultations. Vaccine 2019; 37:3190-3198. [PMID: 31031031 PMCID: PMC6528168 DOI: 10.1016/j.vaccine.2019.04.039] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/10/2019] [Accepted: 04/11/2019] [Indexed: 12/27/2022]
Abstract
There is a major public health need for GBS vaccines for maternal immunization. Important obstacles lie in the way of a pivotal clinical efficacy trial for licensure. A vaccine development pathway based on an immune correlate of protection is envisaged. Key considerations and priority activities for success are presented, based on WHO consultations.
The development of a group B Streptococcus (GBS) vaccine for maternal immunization constitutes a global public health priority, to prevent GBS-associated early life invasive disease, stillbirth, premature birth, maternal sepsis, adverse neurodevelopmental consequences, and to reduce perinatal antibiotic use. Sample size requirements for the conduct of a randomized placebo-controlled trial to assess vaccine efficacy against the most relevant clinical endpoints, under conditions of appropriate ethical standards of care, constitute a significant obstacle on the pathway to vaccine availability. Alternatively, indirect evidence of protection based on immunologic data from vaccine and sero-epidemiological studies, complemented by data from opsonophagocytic in vitro assays and animal models, could be considered as pivotal data for licensure, with subsequent confirmation of effectiveness against disease outcomes in post-licensure evaluations. Based on discussions initiated by the World Health Organization we present key considerations about the potential role of correlates of protection towards an accelerated pathway for GBS vaccine licensure and wide scale use. Priority activities to support progress to regulatory and policy decision are outlined.
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Serocorrelates of protection against infant group B streptococcus disease. THE LANCET. INFECTIOUS DISEASES 2019; 19:e162-e171. [PMID: 30683467 DOI: 10.1016/s1473-3099(18)30659-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/20/2018] [Accepted: 10/24/2018] [Indexed: 12/12/2022]
Abstract
Group B streptococcus (GBS) is a leading cause of young infant mortality and morbidity globally, with vaccines being developed for over four decades but none licensed to date. A serocorrelate of protection against invasive disease in young infants is being considered to facilitate vaccine early licensure, followed by demonstration of efficacy assessed postlicensure. In this Review, we synthesise the available scientific evidence to define an immune correlate associated with GBS disease risk reduction on the basis of studies of natural infection. We summarise studies that have investigated GBS serum anticapsular or anti-protein antibodies, and studies measuring the association between antibody function and disease risk reduction. We highlight how knowledge on the development of correlates of protection from existing vaccines could be harnessed to facilitate GBS vaccine development. These lessons include aggregation of serocorrelates of protection for individual serotypes, understanding the relationship between immunity derived from natural exposure of adults and vaccine-induced immunity, or using extrapolation of protection from in-vitro immunoassay results. We also highlight key considerations for the assessment of the role of antibodies to derive a serocorrelate of risk reduction in future seroepidemiological studies of GBS disease.
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Maternal Carriage of Group B Streptococcus and Escherichia coli in a District Hospital in Mozambique. Pediatr Infect Dis J 2018; 37:1145-1153. [PMID: 30312265 DOI: 10.1097/inf.0000000000001979] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND In low-income countries, data on prevalence and effects of group B Streptococcus (GBS) and Escherichia coli (E. coli) colonization among pregnant women are scarce, but necessary to formulate prevention strategies. We assessed prevalence of GBS and E. coli colonization and factors associated among pregnant women, its effect in newborns and acceptability regarding the utilized sampling methods in a semirural Mozambican hospital. METHODS Pregnant women were recruited from June 2014 to January 2015, during routine antenatal clinics at gestational age ≥ 34 weeks (n = 200); or upon delivery (n = 120). Maternal risk factors were collected. Vaginal and vagino-rectal samples for GBS and E. coli determination were obtained and characterized in terms of antimicrobial resistance and serotype. Anti-GBS antibodies were also determined. Neonatal follow-up was performed in the first 3 months after birth. Semistructured interviews were performed to investigate acceptability of sample collection methods. RESULTS In total, 21.3% of women recruited were GBS carriers, while 16.3% were positive for E. coli. Prevalence of HIV was 36.6%. No association was found between being colonized by GBS and E. coli and maternal risk factors. GBS isolates were fully susceptible to penicillin and ampicillin. Serotypes V (32.4%), Ia (14.7%) and III (10.3%) were the most commonly found and 69.2% of the women tested had immunoglobuline G antibodies against GBS. E. coli isolates showed resistance to ampicillin in 28.9% and trimethoprim/sulfamethoxazole in 61.3% of the cases. CONCLUSION Prevalence of GBS and/or E. coli colonization among pregnant women is high in this semirural community and comparable with those reported in similar settings. Four serotypes accounted for nearly 70% of all isolates of GBS. Population-based data on infant GBS infections would enable the design of prevention strategies for GBS disease in Mozambique.
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Dzanibe S, Madhi SA. Systematic review of the clinical development of group B streptococcus serotype-specific capsular polysaccharide-based vaccines. Expert Rev Vaccines 2018; 17:635-651. [PMID: 29961350 DOI: 10.1080/14760584.2018.1496021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Vaccination against group B Streptococcus (GBS) during pregnancy could provide protection against disease in the mother, fetus, and newborn. Immunity through transplacental acquired antibodies in the newborns could persist through early infancy, reducing the risk of early-onset (<7 days age) and late-onset (7-89 days age) disease. We conducted a systematic review of clinical trials on GBS capsular polysaccharide (CPS) vaccine to assess its safety and immunogenicity in pregnant and nonpregnant adults. AREAS COVERED We searched literature databases PubMed (Medline), Scopus, and the Cochrane library and identified 25 unique records on GBS CPS vaccines with or without conjugant protein. EXPERT COMMENTARY GBS vaccines were well tolerated, with mild local reactogenicity being the main solicited adverse event and no difference in reporting of other serious adverse events compared to placebo recipients. CPS vaccines conjugated to immunogenic proteins induced ≥fourfold increase of serotype-specific antibodies with high longevity (1-2 years); and capable of promoting homotypic GBS opsonophagocytic killing. Feto-maternal transplacental antibody ratio of serotype-specific IgG ranged between 0.49 and 0.81. The clinical relevance of these immunogenicity studies, however, need to be weighed against a correlate of protection against invasive GBS disease in infants, which is yet to be established using a universally accepted standardized assay.
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Affiliation(s)
- Sonwabile Dzanibe
- a Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Sciences , University of the Witwatersrand , Johannesburg , South Africa.,b Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences , University of the Witwatersrand , Johannesburg , South Africa.,c Division of Immunology , University of Cape Town , Cape Town , South Africa
| | - Shabir A Madhi
- a Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Sciences , University of the Witwatersrand , Johannesburg , South Africa.,b Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences , University of the Witwatersrand , Johannesburg , South Africa
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Madhi SA, Koen A, Cutland CL, Jose L, Govender N, Wittke F, Olugbosi M, Sobanjo-Ter Meulen A, Baker S, Dull PM, Narasimhan V, Slobod K. Antibody Kinetics and Response to Routine Vaccinations in Infants Born to Women Who Received an Investigational Trivalent Group B Streptococcus Polysaccharide CRM197-Conjugate Vaccine During Pregnancy. Clin Infect Dis 2018; 65:1897-1904. [PMID: 29029127 PMCID: PMC5848233 DOI: 10.1093/cid/cix666] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 08/22/2017] [Indexed: 11/27/2022] Open
Abstract
Background Maternal vaccination against group B Streptococcus (GBS) might provide protection against invasive GBS disease in infants. We investigated the kinetics of transplacentally transferred GBS serotype-specific capsular antibodies in the infants and their immune response to diphtheria toxoid and pneumococcal vaccination. Methods This phase 1b/2, observer-blind, single-center study (NCT01193920) enrolled infants born to women previously randomized (1:1:1:1) to receive either GBS vaccine at dosages of 0.5, 2.5, or 5.0 μg of each of 3 CRM197-glycoconjugates (serotypes Ia, Ib, and III), or placebo. Infants received routine immunization: combination diphtheria vaccine (diphtheria-tetanus-acellular pertussis–inactivated poliovirus/Haemophilus influenzae type b vaccine; age 6/10/ 14 weeks) and 13-valent pneumococcal CRM197-conjugate vaccine (PCV13; age 6/14 weeks and 9 months). Antibody levels were assessed at birth, day (D) 43, and D91 for GBS serotypes; 1 month postdose 3 (D127) for diphtheria; and 1 month postprimary (D127) and postbooster (D301) doses for pneumococcal serotypes. Results Of 317 infants enrolled, 295 completed the study. In infants of GBS vaccine recipients, GBS serotype-specific antibody geometric mean concentrations were significantly higher than in the placebo group at all timepoints and predictably decreased to 41%–61% and 26%–76% of birth levels by D43 and D91, respectively. Across all groups, ≥95% of infants were seroprotected against diphtheria at D127 and ≥91% of infants had seroprotective antibody levels against each PCV13 pneumococcal serotype at D301. Conclusions Maternal vaccination with an investigational CRM197-glycoconjugate GBS vaccine elicited higher GBS serotype-specific antibody levels in infants until 90 days of age, compared with a placebo group, and did not affect infant immune responses to diphtheria toxoid and pneumococcal vaccination. Clinical Trials Registration NCT01193920.
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Affiliation(s)
- Shabir A Madhi
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand.,National Institute for Communicable Diseases, National Health Laboratory Service, Centre for Vaccines and Immunology, Johannesburg, South Africa
| | - Anthonet Koen
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand
| | - Clare L Cutland
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand
| | - Lisa Jose
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand
| | - Niresha Govender
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand
| | | | | | | | - Sherryl Baker
- GSK and Novartis Vaccines Division, Cambridge, Massachusetts
| | - Peter M Dull
- GSK and Novartis Vaccines Division, Cambridge, Massachusetts
| | - Vas Narasimhan
- GSK and Novartis Vaccines Division, Cambridge, Massachusetts
| | - Karen Slobod
- GSK and Novartis Vaccines Division, Cambridge, Massachusetts
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Fabbrini M, Rigat F, Tuscano G, Chiarot E, Donders G, Devlieger R, Filippini S, Frigimelica E, Forte P, Wittke F, Halperin SA, Slobod K, Grandi G, Margarit I. Functional activity of maternal and cord antibodies elicited by an investigational group B Streptococcus trivalent glycoconjugate vaccine in pregnant women. J Infect 2018; 76:449-456. [DOI: 10.1016/j.jinf.2018.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 10/24/2017] [Accepted: 01/06/2018] [Indexed: 10/18/2022]
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Baker CJ. A Time to Save. J Pediatric Infect Dis Soc 2018; 7:1-5. [PMID: 28093452 DOI: 10.1093/jpids/piw080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/03/2017] [Indexed: 11/13/2022]
Abstract
Group B Streptococcus (GBS), characterized by Lancefield in 1933, was not recognized as a human pathogen until the early 1970s when it emerged and replaced Escherichia coli as the most common cause of sepsis and meningitis among neonates and young infants. This article briefly gives a personnel account of the discovery of clinical syndromes of GBS distinguished by age at onset, vertical mode of transmission for early-onset disease, meningeal tropism for GBS capsular (CPS) type III strains, and protective CPS epitopes. It also reviews the difficult evolution of the now routine program for antenatal GBS culture screening and intrapartum antibiotic prophylaxis, development of the first GBS candidate vaccines, clinical trials documenting the immunogenicity and safety of CPS tetanus toxoid conjugate vaccines, ongoing need to prevent morbidity and mortality in neonates and young infants, and critical need for commercial vaccines for routine use in pregnant women.
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Affiliation(s)
- Carol J Baker
- Department of Pediatrics and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
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Edwards MS, Rench MA, Rinaudo CD, Fabbrini M, Tuscano G, Buffi G, Bartolini E, Bonacci S, Baker CJ, Margarit I. Immune Responses to Invasive Group B Streptococcal Disease in Adults. Emerg Infect Dis 2018; 22:1877-1883. [PMID: 27767008 PMCID: PMC5088039 DOI: 10.3201/eid2211.160914] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Antibodies to capsular polysaccharides and pilus proteins develop in recovering adults. Immunization of nonpregnant adults could help prevent invasive group B Streptococcus (GBS) infections, but adult immune responses have not been investigated. We defined capsular polysaccharide (CPS) and pilus island (PI) surface antigen distribution and expression and immune responses to GBS infection in nonpregnant adults. Prospective surveillance from 7 hospitals in Houston, Texas, USA, identified 102 adults with GBS bacteremia; 43% had skin/soft tissue infection, 16% bacteremia without focus, and 12% osteomyelitis. CPS-specific IgG was determined by ELISA and pilus-specific IgG by multiplex immunoassay. CPS types were Ia (24.5%), Ib (12.7%), II (9.8%), III (16.7%), IV (13.7%), and V (12.7%); 9.8% were nontypeable by serologic methods. Pili, expressed by 89%, were most often PI-2a. CPS and pilus-specific IgG increased during convalescence among patients with strains expressing CPS or PI. All GBS expressed CPS or PI; 79% expressed both. Increased antibodies to CPS and PI during recovery suggests that GBS bacteremia in adults is potentially vaccine preventable.
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Braye K, Ferguson J, Davis D, Catling C, Monk A, Foureur M. Effectiveness of intrapartum antibiotic prophylaxis for early-onset group B Streptococcal infection: An integrative review. Women Birth 2017; 31:244-253. [PMID: 29129472 DOI: 10.1016/j.wombi.2017.10.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 10/13/2017] [Accepted: 10/25/2017] [Indexed: 12/01/2022]
Abstract
BACKGROUND In some countries, up to 30% of women are exposed to intrapartum antibiotic prophylaxis for prevention of early-onset group B Streptococcal infection. Intrapartum antibiotic prophylaxis aims to reduce the risk of neonatal morbidity and mortality from this infection. The intervention may adversely affect non-pathogenic bacteria which are passed to the newborn during birth and are considered important in optimising health. Since many women are offered intrapartum antibiotic prophylaxis, effectiveness and implications of this intervention need to be established. This review considers clinical trials and observational studies analysing the effectiveness of intrapartum antibiotic prophylaxis. METHODS An integrative literature review was conducted. One systematic review, three clinical trials and five observational studies were identified for appraisal. FINDINGS Randomised controlled trials found intrapartum antibiotic prophylaxis effective but all retrieved randomised clinical trials had significant methodological flaws. High quality observational studies reported high rates of effectiveness but revealed less than optimal adherence to screening and administration of the prophylaxis. Scant consideration was given to short term risks, and long-term consequences were not addressed. DISCUSSION Studies found intrapartum antibiotic prophylaxis to be effective. However, evidence was not robust and screening and prophylaxis have limitations. Emerging evidence links intrapartum antibiotic prophylaxis to adverse short and longer-term neonatal outcomes. CONCLUSION Our review found high quality evidence of the effectiveness of intrapartum antibiotic prophylaxis was limited. Lack of consideration of potential risks of the intervention was evident. Women should be enabled to make informed decisions about GBS management. More research needs to be done in this area.
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Affiliation(s)
- Kathryn Braye
- Centre for Midwifery, Child and Family Health, University of Technology Sydney, Australia.
| | - John Ferguson
- Pathology North, Hunter New England Local Health District, Newcastle, NSW, Australia
| | - Deborah Davis
- Faculty of Health, University of Canberra, Australia
| | - Christine Catling
- Centre for Midwifery, Child and Family Health, University of Technology Sydney, Australia
| | - Amy Monk
- Centre for Midwifery, Child and Family Health, University of Technology Sydney, Australia
| | - Maralyn Foureur
- Centre for Midwifery, Child and Family Health, University of Technology Sydney, Australia
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Group B Streptococcus: developing a correlate of protection for a vaccine against neonatal infections. Curr Opin Infect Dis 2017; 29:262-7. [PMID: 26926474 DOI: 10.1097/qco.0000000000000266] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Maternal vaccination to prevent invasive Group B Streptococcus (GBS) disease in infants is an important alternative strategy to intrapartum antibiotic prophylaxis. Licensure of GBS vaccines could be expedited using immunological correlates of protection. RECENT FINDINGS Between 2014 and 2015, we identified two studies that demonstrated an inverse association between invasive GBS disease and maternal serotype III capsular antibody levels greater than 1 μg/ml and greater than 3 μg/ml, and higher maternal antibody levels were associated with protection against serotype Ia disease. Furthermore, serotype Ia and III antibody levels greater than 3 μg/ml were associated with a reduced risk of GBS colonization in pregnant women.Experimental studies have investigated the use of GBS surface proteins as vaccine candidates. Although the immunogenic potential of pilus island and other surface proteins has been shown in animal-model studies, no association between maternal pilus island antibody levels and invasive GBS disease was demonstrated in infants. Additionally, several novel innate immune mediators that prevent GBS infection have been described in human and experimental studies. SUMMARY Recent studies suggest that maternal capsular antibody thresholds may be used as immunological correlates of protection for vaccine licensure. Surface proteins, as candidate vaccines or conjugates to the polysaccharide-protein vaccine, may broaden protection against invasive GBS disease.
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Vornhagen J, Adams Waldorf KM, Rajagopal L. Perinatal Group B Streptococcal Infections: Virulence Factors, Immunity, and Prevention Strategies. Trends Microbiol 2017. [PMID: 28633864 DOI: 10.1016/j.tim.2017.05.013] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Group B streptococcus (GBS) or Streptococcus agalactiae is a β-hemolytic, Gram-positive bacterium that is a leading cause of neonatal infections. GBS commonly colonizes the lower gastrointestinal and genital tracts and, during pregnancy, neonates are at risk of infection. Although intrapartum antibiotic prophylaxis during labor and delivery has decreased the incidence of early-onset neonatal infection, these measures do not prevent ascending infection that can occur earlier in pregnancy leading to preterm births, stillbirths, or late-onset neonatal infections. Prevention of GBS infection in pregnancy is complex and is likely influenced by multiple factors, including pathogenicity, host factors, vaginal microbiome, false-negative screening, and/or changes in antibiotic resistance. A deeper understanding of the mechanisms of GBS infections during pregnancy will facilitate the development of novel therapeutics and vaccines. Here, we summarize and discuss important advancements in our understanding of GBS vaginal colonization, ascending infection, and preterm birth.
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Affiliation(s)
- Jay Vornhagen
- Department of Global Health, University of Washington, Seattle, WA, USA; Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Kristina M Adams Waldorf
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA, USA; Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
| | - Lakshmi Rajagopal
- Department of Global Health, University of Washington, Seattle, WA, USA; Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA; Department of Pediatrics, University of Washington, Seattle, WA, USA.
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Kim HW, Lee JH, Cho HK, Lee H, Seo HS, Lee S, Kim KH. Opsonophagocytic Antibodies to Serotype Ia, Ib, and III Group B Streptococcus among Korean Infants and in Intravenous Immunoglobulin Products. J Korean Med Sci 2017; 32:737-743. [PMID: 28378545 PMCID: PMC5383604 DOI: 10.3346/jkms.2017.32.5.737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 01/27/2017] [Indexed: 11/20/2022] Open
Abstract
Group B streptococcus (GBS) infection is a leading cause of sepsis and meningitis among infants, and is associated with high rates of morbidity and mortality in many countries. Protection against GBS typically involves antibody-mediated opsonization by phagocytes and complement components. The present study evaluated serotype-specific functional antibodies to GBS among Korean infants and in intravenous immunoglobulin (IVIG) products. An opsonophagocytic killing assay (OPA) was used to calculate the opsonization indices (OIs) of functional antibodies to serotypes Ia, Ib, and III in 19 IVIG products from 5 international manufacturers and among 98 Korean infants (age: 0-11 months). The GBS Ia, Ib, and III serotypes were selected because they are included in a trivalent GBS vaccine formulation that is being developed. The OI values for the IVIG products were 635-5,706 (serotype Ia), 488-1,421 (serotype Ib), and 962-3,315 (serotype III), and none of the IVIG lots exhibited undetectable OI values (< 4). The geometric mean OI values were similar for all 3 serotypes when we compared the Korean manufacturers. The seropositive rate among infants was significantly lower for serotype Ia (18.4%), compared to serotype Ib and serotype III (both, 38.8%). Infant age of ≥ 3 months was positively correlated with the seropositive rates for each serotype. Therefore, only a limited proportion of infants exhibited protective immunity against serotype Ia, Ib, and III GBS infections. IVIG products that exhibit high antibody titers may be a useful therapeutic or preventive measure for infants. Further studies are needed to evaluate additional serotypes and age groups.
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Affiliation(s)
- Han Wool Kim
- Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea
| | - Ji Hyen Lee
- Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea
- Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea
| | - Hye Kyung Cho
- Department of Pediatrics, Graduate School of Medicine, Gachon University, Incheon, Korea
| | - Hyunju Lee
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Ho Seong Seo
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Soyoung Lee
- Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea
| | - Kyung Hyo Kim
- Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea
- Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea.
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Association between functional antibody against Group B Streptococcus and maternal and infant colonization in a Gambian cohort. Vaccine 2017; 35:2970-2978. [PMID: 28449969 PMCID: PMC5432431 DOI: 10.1016/j.vaccine.2017.04.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/03/2017] [Accepted: 04/05/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Vertical transmission of Group B Streptococcus (GBS) is a prerequisite for early-onset disease and a consequence of maternal GBS colonization. Disease protection is associated with maternally-derived anti-GBS antibody. Using a novel antibody-mediated C3b/iC3b deposition flow cytometry assay which correlates with opsonic killing we developed a model to assess the impact of maternally-derived functional anti-GBS antibody on infant GBS colonization from birth to day 60-89 of life. METHODS Rectovaginal swabs and cord blood (birth) and infant nasopharyngeal/rectal swabs (birth, day 6 and day 60-89) were obtained from 750 mother/infant pairs. Antibody-mediated C3b/iC3b deposition with cord and infant sera was measured by flow cytometry. RESULTS We established that as maternally-derived anti-GBS functional antibody increases, infant colonization decreases at birth and up to three months of life, the critical time window for the development of GBS disease. Further, we observed a serotype (ST)-dependent threshold above which no infant was colonized at birth. Functional antibody above the upper 95th confidence interval for the geometric mean concentration was associated with absence of infant GBS colonization at birth for STII (p<0.001), STIII (p=0.01) and STV (p<0.001). Increased functional antibody was also associated with clearance of GBS between birth and day 60-89. CONCLUSIONS Higher concentrations of maternally-derived antibody-mediated complement deposition are associated with a decreased risk of GBS colonization in infants up to day 60-89 of life. Our findings are of relevance to establish thresholds for protection following vaccination of pregnant women with future GBS vaccines.
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Madhi SA, Dangor Z. Prospects for preventing infant invasive GBS disease through maternal vaccination. Vaccine 2017; 35:4457-4460. [PMID: 28237500 DOI: 10.1016/j.vaccine.2017.02.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/05/2017] [Accepted: 02/08/2017] [Indexed: 11/26/2022]
Abstract
Group B streptococcus (GBS) is a leading cause of neonatal sepsis, with the highest incidence (1.3 per 1000 live births) reported from Africa. Although the incidence of invasive GBS disease is reportedly low in South Asia, there is disconnect between prevalence of maternal recto-vaginal colonization and the incidence of early-onset disease (EOD). This is possibly due to case-ascertainment biases that omit investigation of newborns dying on day-0 of life, which accounts for >90% of EOD. Furthermore, GBS is associated with approximately 15% of all infection related stillbirths. Vaccination of pregnant women with a serotype-specific polysaccharide epitope vaccine could possibly protect against EOD and late-onset disease (LOD) in their infants through transplacental transfer of serotype-specific capsular antibody. Furthermore, vaccination of pregnant women might also protect against impaired neurodevelopment following GBS associated neonatal sepsis, and fetal loss/stillbirths. Licensure of a GBS vaccine might be feasible based on safety evaluation and a sero-correlate of protection, with vaccine effectiveness subsequently being demonstrated in phase IV studies. A randomized-controlled trial would, however, be best suited as a vaccine-probe to fully characterize the contribution of GBS to neonatal sepsis associated morbidity and mortality and adverse fetal outcomes.
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Affiliation(s)
- Shabir A Madhi
- Medical Research Council, Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, South Africa; Department of Science and Technology/National Research Foundation, Vaccine Preventable Diseases, Faculty of Health Sciences, University of the Witwatersrand, South Africa.
| | - Ziyaad Dangor
- Medical Research Council, Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, South Africa; Department of Science and Technology/National Research Foundation, Vaccine Preventable Diseases, Faculty of Health Sciences, University of the Witwatersrand, South Africa; Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, South Africa.
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Rick AM, Aguilar A, Cortes R, Gordillo R, Melgar M, Samayoa-Reyes G, Frank DN, Asturias EJ. Group B Streptococci Colonization in Pregnant Guatemalan Women: Prevalence, Risk Factors, and Vaginal Microbiome. Open Forum Infect Dis 2017; 4:ofx020. [PMID: 28480290 PMCID: PMC5414013 DOI: 10.1093/ofid/ofx020] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 02/06/2017] [Indexed: 12/13/2022] Open
Abstract
Background Infection causes 1 of every 5 neonatal deaths globally. Group B Streptococcus (GBS) is the most significant pathogen, although little is known about its epidemiology and risk in low-income countries. Methods A cross-sectional study in 2015 at a public hospital in Guatemala City enrolled women ≥35 weeks’ gestation. Vaginal and rectal swabs were processed using Lim broth and GBS CHROMagar then agglutination testing. Risk factors were assessed using multivariate analysis. Vaginal microbiota were profiled by 16S ribosomal ribonucleic acid sequencing in a subset of 94 women. Results Of 896 pregnant women, 155 (17.3%; 95% confidence interval [CI], 14.9–19.9) were GBS colonized. Colonization was associated with history of previous infant with poor outcome (odds ratio [OR], 1.94; 95% CI, 1.15–3.27) and increasing maternal age (OR, 1.05; 95% CI, 1.02–1.09). Multiparity was protective (OR, .39; 95% CI, .21–.72). Four (6%) GBS-exposed infants had early-onset neonatal sepsis. Vaginal microbiome composition was associated with previous antibiotic exposure (P = .003) and previous low birth weight infant (P = .03), but not GBS colonization (P = .72). Several individual taxa differed in abundance between colonized and noncolonized women. Conclusions Group B Streptococcus is prevalent in pregnant women from Guatemala with different risk factors than previously described. Although the vaginal microbiome was not altered significantly in GBS-colonized women, use of antibiotics had an effect on its composition.
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Affiliation(s)
- Anne-Marie Rick
- Department of Pediatrics, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora
| | - Angie Aguilar
- Facultad de Medicina, Universidad Francisco Marroquín, Guatemala City
| | - Rosita Cortes
- Department of Pediatrics and Microbiology, Hospital Roosevelt, Guatemala City
| | - Remei Gordillo
- Department of Pediatrics and Microbiology, Hospital Roosevelt, Guatemala City
| | - Mario Melgar
- Department of Pediatrics and Microbiology, Hospital Roosevelt, Guatemala City
| | | | - Daniel N Frank
- Division of Infectious Diseases, School of Medicine, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora
| | - Edwin J Asturias
- Department of Pediatrics, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora.,Center for Global Health and Department of Epidemiology, Colorado School of Public Health, Aurora
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Kobayashi M, Vekemans J, Baker CJ, Ratner AJ, Le Doare K, Schrag SJ. Group B Streptococcus vaccine development: present status and future considerations, with emphasis on perspectives for low and middle income countries. F1000Res 2016; 5:2355. [PMID: 27803803 PMCID: PMC5070600 DOI: 10.12688/f1000research.9363.1] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/08/2016] [Indexed: 01/07/2023] Open
Abstract
Globally, group B Streptococcus (GBS) remains the leading cause of sepsis and meningitis in young infants, with its greatest burden in the first 90 days of life. Intrapartum antibiotic prophylaxis (IAP) for women at risk of transmitting GBS to their newborns has been effective in reducing, but not eliminating, the young infant GBS disease burden in many high income countries. However, identification of women at risk and administration of IAP is very difficult in many low and middle income country (LMIC) settings, and is not possible for home deliveries. Immunization of pregnant women with a GBS vaccine represents an alternate pathway to protecting newborns from GBS disease, through the transplacental antibody transfer to the fetus in utero. This approach to prevent GBS disease in young infants is currently under development, and is approaching late stage clinical evaluation. This manuscript includes a review of the natural history of the disease, global disease burden estimates, diagnosis and existing control options in different settings, the biological rationale for a vaccine including previous supportive studies, analysis of current candidates in development, possible correlates of protection and current status of immunogenicity assays. Future potential vaccine development pathways to licensure and use in LMICs, trial design and implementation options are discussed, with the objective to provide a basis for reflection, rather than recommendations.
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Affiliation(s)
- Miwako Kobayashi
- National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, USA
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, USA
| | - Johan Vekemans
- Initiative for Vaccine Research, World Health Organization, Geneva, Switzerland
| | - Carol J. Baker
- Department of Pediatrics, Baylor College of Medicine, Houston, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, USA
- Center for Vaccine Awareness and Research, Texas Children's Hospital, Houston, USA
| | - Adam J. Ratner
- Departments of Pediatrics and Microbiology, New York University School of Medicine, New York, USA
| | - Kirsty Le Doare
- Centre for International Child Health, Imperial College, London, UK
| | - Stephanie J. Schrag
- National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, USA
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Fabbrini M, Rigat F, Rinaudo CD, Passalaqua I, Khacheh S, Creti R, Baldassarri L, Carboni F, Anderloni G, Rosini R, Maione D, Grandi G, Telford JL, Margarit I. The Protective Value of Maternal Group B Streptococcus Antibodies: Quantitative and Functional Analysis of Naturally Acquired Responses to Capsular Polysaccharides and Pilus Proteins in European Maternal Sera. Clin Infect Dis 2016; 63:746-753. [PMID: 27402816 DOI: 10.1093/cid/ciw377] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 06/02/2016] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Group B Streptococcus (GBS) is a major cause of neonatal sepsis and meningitis. A vaccine targeting pregnant women could protect infants through placentally transferred antibodies. The association between GBS maternal antibody concentrations and the risk of neonatal infection has been investigated in US and African populations. Here we studied naturally acquired immunoglobulin G (IgG) responses to GBS capsular polysaccharides (CPS) and pilus proteins in European pregnant women. METHODS Maternal sera were prospectively collected in 8 EU countries from 473 GBS non-colonized and 984 colonized pregnant women who delivered healthy neonates and from 153 mothers of infants with GBS disease. GBS strains from these colonized women and infected infants were obtained in parallel and their capsular and pilus types were identified by serological and molecular methods. Maternal serum concentrations of IgG anti- Ia, -Ib, -III and -V polysaccharides and anti-BP-1, -AP1-2a and -BP-2b pilus proteins were determined by enzyme-linked immunosorbent assay. Antibody functional activity was quantified by Opsonophagocytic Killing Assay. RESULTS Antibody levels against CPS and pilus proteins were significantly higher in GBS colonized women delivering healthy babies than in mothers of neonates with GBS disease or non-colonized women. Moreover, maternal anti-capsular IgG concentrations showed a significant correlation with functional titers measured by Opsonophagocytic Killing Assay. CONCLUSIONS Maternal anti-capsular IgG concentrations above 1 µg/mL mediated GBS killing in vitro and were predicted to respectively reduce by 81% (95% confidence interval, 40%-100%) and 78% (45%-100%) the risk of GBS Ia and III early-onset disease in Europe.
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Berardi A, Ferrari F. Group B streptococcal maternal vaccination, the goal is near. THE LANCET. INFECTIOUS DISEASES 2016; 16:871-2. [PMID: 27139806 DOI: 10.1016/s1473-3099(16)30048-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 04/04/2016] [Indexed: 10/21/2022]
Affiliation(s)
- Alberto Berardi
- Unità Operativa di Terapia Intensiva Neonatale, Dipartimento Integrato Materno-Infantile, Azienda Ospedaliero-Universitaria Policlinico, 41124 Modena, Italy.
| | - Fabrizio Ferrari
- Unità Operativa di Terapia Intensiva Neonatale, Dipartimento Integrato Materno-Infantile, Azienda Ospedaliero-Universitaria Policlinico, 41124 Modena, Italy
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