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Duguma T, Dinka H. In Silico Identification and Characterization of Drug Targets in Streptococcus pneumoniae ATCC 700669 (Serotype 23F) by Subtractive Genomics. BIOMED RESEARCH INTERNATIONAL 2024; 2024:5917667. [PMID: 38283072 PMCID: PMC10821801 DOI: 10.1155/2024/5917667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/28/2023] [Accepted: 01/05/2024] [Indexed: 01/30/2024]
Abstract
Streptococcus pneumoniae (S. pneumoniae) is an important pathogen worldwide that causes pneumococcal infections which are related to high rates of morbidity and mortality especially in young children, older adults, and immune-compromised persons. Antibiotic resistance in S. pneumoniae is a serious problem across the world from time to time, resulting in treatment failure and diminished value of older medicines. Therefore, the objective of this study was to identify new putative drug targets against S. pneumoniae serotype 23F by using subtractive genomics. By using bioinformatics tools such as NCBI, UniProt KB, PDB, KEGG, DEG, PSORTb, CD hit, DrugBank database, and other softwares, proteins involved in unique metabolic pathways of S. pneumoniae serotype 23F were studied. The result indicates that this serotype consists of 97 metabolic pathways of which 74 are common with that of human, and 23 pathways are unique to the serotype 23F. After investigation and analysis of essentiality, nonhomology, subcellular localization, having drug targets, and enzymatic activity, four proteins were prioritized as druggable targets. These druggable proteins include UDP-N-acetylglucosamine 1-carboxyvinyltransferase, UDP-N-acetyl muramate dehydrogenase, D-alanine-D-alanine ligase, and alanine racemase that are found in S. pneumoniae serotype 23F. All these four proteins are essential, are nonhomologous with human proteins, have drug targets, and are located in cell cytoplasm. Therefore, the authors recommend these proteins to be used for efficient drug design against S. pneumoniae serotype 23F after experimental validation for essentiality and druggability.
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Affiliation(s)
- Tolossa Duguma
- Department of Biotechnology, Wolkite University, Wolkite, Ethiopia
| | - Hunduma Dinka
- Department of Applied Biology, Adama Science and Technology University, Adama, Ethiopia
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Tiley KS, Ratcliffe H, Voysey M, Jefferies K, Sinclair G, Carr M, Colin-Jones R, Smith D, Bowman J, Hart T, Kandasamy R, Hinds J, Gould K, Berbers G, Tcherniaeva I, Robinson H, Plested E, Aley P, Snape MD. Nasopharyngeal Carriage of Pneumococcus in Children in England up to 10 Years After 13-Valent Pneumococcal Conjugate Vaccine Introduction: Persistence of Serotypes 3 and 19A and Emergence of 7C. J Infect Dis 2023; 227:610-621. [PMID: 36130327 PMCID: PMC9978316 DOI: 10.1093/infdis/jiac376] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/22/2022] [Accepted: 09/12/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Monitoring changes in pharyngeal carriage of pneumococcus in children following 13-valent pneumococcal conjugate vaccine (PCV13) introduction in the United Kingdom in 2010 informs understanding of patterns of invasive pneumococcal disease (IPD) incidence. METHODS Nasopharyngeal swabs from healthy children vaccinated with PCV13 according to schedule (2, 4, and 12 months) were cultured and serotyped. Results for children aged 13-48 months were compared between 2014-2015 and 2017-2019 and with children aged 6-12 months (2017-2020). Blood was obtained from a subset of children for pneumococcal serotype-specific immunoglobulin G (IgG). RESULTS Total pneumococcal carriage at 13-48 months was 47.9% (473/988) in 2014-2015 and 51.8% (412/795) in 2017-2019 (P = .10); at age 6-12 months this value was 44.6% (274/615). In 2017-2019, 2.9% (95% confidence interval, 1.8%-4.3%) of children aged 13-48 months carried PCV13 serotypes (mainly 3 [1.5%] and 19A [0.8%]) and >20% carried the additional 20-valent PCV (PCV20) serotypes. Similar proportions of children had IgG ≥0.35 IU/mL for each serotype in 2014-2015 and 2017-2019. Serotype 7C carriage increased significantly (P < .01) between 2014-2015 and 2017-2019. Carriage of PCV20 serotypes 8 and 12F, both major causes of IPD, was rare. CONCLUSIONS Introduction of PCV20, if licensed for children, could significantly change the composition of pneumococcal serotypes carried in the pharynx of UK children. CLINICAL TRIALS REGISTRATION NCT03102840.
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Affiliation(s)
- Karen S Tiley
- Correspondence: Karen Tiley, PhD, Oxford Vaccine Group, Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Old Road, Headington, Oxford OX3 7LE, UK ()
| | - Helen Ratcliffe
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Merryn Voysey
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Kimberley Jefferies
- Present affiliations: University Hospital Southampton NHS Foundation Trust, Princess Anne Hospital, Southampton, United Kingdom
| | - Gemma Sinclair
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | | | - Rachel Colin-Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | | | | | | | | | - Jason Hinds
- Institute for Infection and Immunity, St George’s University, London, United Kingdom
- BUGS Bioscience, London Bioscience Innovation Centre, London, United Kingdom
| | - Katherine Gould
- Institute for Infection and Immunity, St George’s University, London, United Kingdom
- BUGS Bioscience, London Bioscience Innovation Centre, London, United Kingdom
| | - Guy Berbers
- Immunology, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Irina Tcherniaeva
- Immunology, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Hannah Robinson
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford, United Kingdom, and
- National Institute for Health Research Clinical Research Network Thames Valley and South Midlands, Oxford, United Kingdom
| | - Emma Plested
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford, United Kingdom, and
- National Institute for Health Research Clinical Research Network Thames Valley and South Midlands, Oxford, United Kingdom
| | - Parvinder Aley
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford, United Kingdom, and
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Halder T, Yadav SK, Yadav S. Synthesis of the trisaccharide repeating unit of Stenotrophomonas maltophilia O6 antigen through step-wise and one-pot approaches. Carbohydr Res 2022; 521:108669. [PMID: 36099720 DOI: 10.1016/j.carres.2022.108669] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/19/2022] [Accepted: 08/30/2022] [Indexed: 11/02/2022]
Abstract
Synthetic conjugate vaccines are an important area of research for the prevention and occurrence of diseases caused by Gram-negative bacteria. For the development of such vaccines, access to the pure and homogeneous oligosaccharide fragments of the bacterial cell surface polysaccharides are necessary. Stenotrophomonas maltophilia is a typical opportunistic Gram-negative bacteria that causes severe pulmonary and other infections; often in hospitalized patients. With the emergence of multidrug resistant strains and increased virulence, new therapeutic strategies are needed to combat the threat. Herein, we report the syntheses of the trisaccharide repeating unit of S. maltophilia O6 antigen through stepwise and one-pot assemblies of the trisaccharide. The target trisaccharide was appended with a 2-aminoethyl linker that could provide the opportunity for conjugation to carrier proteins for the synthesis of vaccine candidates.
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Affiliation(s)
- Tanmoy Halder
- Department of Chemistry & Chemical Biology, Indian Institute of Technology (ISM) Dhanbad, Dhanbad, 826004, Jharkhand, India
| | - Sunil K Yadav
- Department of Chemistry & Chemical Biology, Indian Institute of Technology (ISM) Dhanbad, Dhanbad, 826004, Jharkhand, India
| | - Somnath Yadav
- Department of Chemistry & Chemical Biology, Indian Institute of Technology (ISM) Dhanbad, Dhanbad, 826004, Jharkhand, India.
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Colijn C, Corander J, Croucher NJ. Designing ecologically optimized pneumococcal vaccines using population genomics. Nat Microbiol 2020; 5:473-485. [PMID: 32015499 PMCID: PMC7614922 DOI: 10.1038/s41564-019-0651-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022]
Abstract
Streptococcus pneumoniae (the pneumococcus) is a common nasopharyngeal commensal that can cause invasive pneumococcal disease (IPD). Each component of current protein-polysaccharide conjugate vaccines (PCVs) generally induces immunity specific to one of the approximately 100 pneumococcal serotypes, and typically eliminates it from carriage and IPD through herd immunity. Overall carriage rates remain stable owing to replacement by non-PCV serotypes. Consequently, the net change in IPD incidence is determined by the relative invasiveness of the pre- and post-PCV-carried pneumococcal populations. In the present study, we identified PCVs expected to minimize the post-vaccine IPD burden by applying Bayesian optimization to an ecological model of serotype replacement that integrated epidemiological and genomic data. We compared optimal formulations for reducing infant-only or population-wide IPD, and identified potential benefits to including non-conserved pneumococcal carrier proteins. Vaccines were also devised to minimize IPD resistant to antibiotic treatment, despite the ecological model assuming that resistance levels in the carried population would be preserved. We found that expanding infant-administered PCV valency is likely to result in diminishing returns, and that complementary pairs of infant- and adult-administered vaccines could be a superior strategy. PCV performance was highly dependent on the circulating pneumococcal population, further highlighting the advantages of a diversity of anti-pneumococcal vaccination strategies.
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Affiliation(s)
- Caroline Colijn
- Department of Mathematics, Simon Fraser University, Burnaby, BC, Canada.
- Department of Mathematics, Imperial College London, London, UK.
| | - Jukka Corander
- Department of Biostatistics, University of Oslo, Oslo, Norway
- Helsinki Institute of Information Technology, Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
- Parasites & Microbes, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK
| | - Nicholas J Croucher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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Oligbu G, Collins S, Djennad A, Sheppard CL, Fry NK, Andrews NJ, Borrow R, Ramsay ME, Ladhani SN. Effect of Pneumococcal Conjugate Vaccines on Pneumococcal Meningitis, England and Wales, July 1, 2000-June 30, 2016. Emerg Infect Dis 2020; 25:1708-1718. [PMID: 31441745 PMCID: PMC6711218 DOI: 10.3201/eid2509.180747] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We describe the effects of the 7-valent (PCV7) and 13-valent (PCV13) pneumococcal conjugate vaccines on pneumococcal meningitis in England and Wales during July 1, 2000–June 30, 2016. Overall, 84,473 laboratory-confirmed invasive pneumococcal disease cases, including 4,160 (4.9%) cases with meningitis, occurred. PCV7 implementation in 2006 did not lower overall pneumococcal meningitis incidence because of replacement with non–PCV7-type meningitis incidence. Replacement with PCV13 in 2010, however, led to a 48% reduction in pneumococcal meningitis incidence by 2015–16. The overall case-fatality rate was 17.5%: 10.7% among patients <5 years of age, 17.3% among patients 5–64 years of age, and 31.9% among patients >65 years of age. Serotype 8 was associated with increased odds of death (adjusted odds ratio 2.9, 95% CI 1.8–4.7). In England and Wales, an effect on pneumococcal meningitis was observed only after PCV13 implementation. Further studies are needed to assess pneumococcal meningitis caused by the replacing serotypes.
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Colombo C, Pitirollo O, Lay L. Recent Advances in the Synthesis of Glycoconjugates for Vaccine Development. Molecules 2018; 23:molecules23071712. [PMID: 30011851 PMCID: PMC6099631 DOI: 10.3390/molecules23071712] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/09/2018] [Accepted: 07/11/2018] [Indexed: 12/25/2022] Open
Abstract
During the last decade there has been a growing interest in glycoimmunology, a relatively new research field dealing with the specific interactions of carbohydrates with the immune system. Pathogens’ cell surfaces are covered by a thick layer of oligo- and polysaccharides that are crucial virulence factors, as they mediate receptors binding on host cells for initial adhesion and organism invasion. Since in most cases these saccharide structures are uniquely exposed on the pathogen surface, they represent attractive targets for vaccine design. Polysaccharides isolated from cell walls of microorganisms and chemically conjugated to immunogenic proteins have been used as antigens for vaccine development for a range of infectious diseases. However, several challenges are associated with carbohydrate antigens purified from natural sources, such as their difficult characterization and heterogeneous composition. Consequently, glycoconjugates with chemically well-defined structures, that are able to confer highly reproducible biological properties and a better safety profile, are at the forefront of vaccine development. Following on from our previous review on the subject, in the present account we specifically focus on the most recent advances in the synthesis and preliminary immunological evaluation of next generation glycoconjugate vaccines designed to target bacterial and fungal infections that have been reported in the literature since 2011.
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Affiliation(s)
- Cinzia Colombo
- Dipartimento di Chimica, Universita' degli Studi di Milano, via Golgi 19, 20133 Milano, Italy.
| | - Olimpia Pitirollo
- Dipartimento di Chimica, Universita' degli Studi di Milano, via Golgi 19, 20133 Milano, Italy.
| | - Luigi Lay
- Dipartimento di Chimica, Universita' degli Studi di Milano, via Golgi 19, 20133 Milano, Italy.
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Southern J, Andrews N, Sandu P, Sheppard CL, Waight PA, Fry NK, Van Hoek AJ, Miller E. Pneumococcal carriage in children and their household contacts six years after introduction of the 13-valent pneumococcal conjugate vaccine in England. PLoS One 2018; 13:e0195799. [PMID: 29799839 PMCID: PMC5969732 DOI: 10.1371/journal.pone.0195799] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/29/2018] [Indexed: 12/14/2022] Open
Abstract
Background In April 2010, 13-valent pneumococcal conjugate vaccine (PCV13) replaced PCV7 in the infant immunisation schedule in England and Wales. Despite limited serotype replacement in invasive pneumococcal disease (IPD) during the first four post-PCV13 years, non-vaccine type (NVT) IPD increased substantially in 2014/15. We undertook a carriage study in 2015/16 to help understand the reasons for this increase. Methods and findings Families with a child aged <5 years attending a participating general practice in Gloucestershire or Hertfordshire were invited to provide nasopharyngeal swabs from all consenting members. Swabs from 650 individuals (293 under five, 73 five to twenty and 284 >twenty years) were cultured and serotyped for Streptococcus pneumoniae. Results were compared with those from three previous household studies conducted in the same populations between 2001 to 2013, and with the serotypes causing IPD to estimate case-carrier ratios (CCRs). Overall carriage prevalence did not differ between the four carriage studies with reductions in vaccine-type carriage offset by increases in NVT carriage. While no individual NVT serotype showed an increase in CCR from 2012/13, the composition of the serotypes comprising the NVT group differed such that the overall CCR of the NVT group had significantly increased since 2012/13. Carriage of two PCV13 serotypes, 3 and 19A, was found in 2015/16 (3/650 = 0.5% and 2/650 = 0.3% respectively) with no overall reduction in carriage prevalence of PCV13-7 serotypes since 2012/13, though 6C prevalence, a vaccine-related serotype, had reduced from 1.8% in 2012/13 to 2/648 (0.3%) in 2015/16, p = 0.013. Conclusions There was continuing evolution in carried NVTs six years after PCV13 introduction which, in addition to being vaccine-driven, could also reflect natural secular changes in certain NVTs. This poses challenges in predicting future trends in IPD. Elimination of carriage and disease due to serotypes 3 and 19A may not be achieved by PCV13.
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Affiliation(s)
- Jo Southern
- Immunisation, Hepatitis and Blood Safety Department, National Infection Service, Public Health England, London, United Kingdom
- * E-mail:
| | - Nick Andrews
- Statistics, Modelling and Economics Department, Colindale, National Infection Service, Public Health England, London, United Kingdom
| | - Pamela Sandu
- Respiratory and Vaccine Preventable Bacteria Reference Unit, National Infection Service, Public Health England, London, United Kingdom
| | - Carmen L. Sheppard
- Respiratory and Vaccine Preventable Bacteria Reference Unit, National Infection Service, Public Health England, London, United Kingdom
| | - Pauline A. Waight
- Immunisation, Hepatitis and Blood Safety Department, National Infection Service, Public Health England, London, United Kingdom
| | - Norman K. Fry
- Respiratory and Vaccine Preventable Bacteria Reference Unit, National Infection Service, Public Health England, London, United Kingdom
| | - Albert Jan Van Hoek
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Elizabeth Miller
- Immunisation, Hepatitis and Blood Safety Department, National Infection Service, Public Health England, London, United Kingdom
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Voysey M, Pollard AJ, Perera R, Shrestha S, Thorson S, Fanshawe TR. Use of weighted multivariate estimates in trials of multi-serotype vaccines to simplify interpretation of treatment differences. PLoS One 2018; 13:e0196200. [PMID: 29702658 PMCID: PMC5922548 DOI: 10.1371/journal.pone.0196200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 04/07/2018] [Indexed: 11/19/2022] Open
Abstract
Background Many vaccines contain multiple components. Licensed pneumococcal conjugate vaccines (PCV) contain polysaccharides from 7, 10, or 13 different serotypes of Streptococcus pneumoniae. The main outcomes in randomised trials of pneumococcal vaccines are serotype-specific antibody measures. Comparisons are made between groups for each serotype, resulting in multiple separate comparisons of treatment effects which can be complicated to interpret. We investigated methods for computing the overall difference between vaccine groups across all serotypes. Methods Pneumococcal antibody concentrations were obtained from a randomised controlled trial of ten-valent pneumococcal vaccine, conducted in Kathmandu, Nepal. Infants received either 2 priming doses of vaccine at 6 and 14 weeks of age followed by a booster (2+1), or 3 priming doses at 6, 10, and 14 weeks of age with no booster (3+0). The overall difference between vaccine schedules across all serotypes was computed at each visit using a multivariate linear model with equal weights for each serotype. Alternative weights were derived from invasive pneumococcal disease cases in Nepal, Bangladesh and Pakistan, and from estimates of the relative invasiveness of each serotype and used in sensitivity analyses. Results When 10 separate estimates of treatment differences were computed the ratio of antibody responses for each serotype in the 2+1 group compared with the 3+0 group at 10 months of age varied greatly, with serotype-specific GMRs ranging from 2.80 for serotype 14, to 9.14 for serotype 18C. Using equal weights for each serotype, the overall geometric mean ratio (GMR) was 5.02 (95% CI 4.06−6.22) at 10 months of age, and 1.46 (95% CI 1.14−1.88) at 3 years of age. Using weights based on disease incidence gave GMRs ranging from 5.15 to 6.63 at 10 months of age, and 1.47 to 1.78 at 3 years of age. Using weights based on relative invasiveness gave estimates of 6.81 and 1.59, at 10 months and 3 years respectively. Conclusion PCV clinical trial data have a multivariate structure with correlated outcomes for different serotypes. When analysing each serotype separately, the multiple estimates of the treatment effect can complicate the interpretation of trial results. Reporting a single overall estimate which accounts for the correlation between outcomes can simplify such interpretation. Treatment effects can be weighted equally or alternative weights derived from independent data can be used. Many modern vaccines have multiple components, such as quadrivalent meningococcal group ACWY vaccine or four-component group B meningococcal vaccine, thus these methods are widely applicable.
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Affiliation(s)
- Merryn Voysey
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - Andrew J. Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Rafael Perera
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Shrijana Shrestha
- Paediatric Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Stephen Thorson
- Paediatric Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Thomas R. Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
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Weinberger DM, Grant LR, Weatherholtz RC, Warren JL, O'Brien KL, Hammitt LL. Relating Pneumococcal Carriage Among Children to Disease Rates Among Adults Before and After the Introduction of Conjugate Vaccines. Am J Epidemiol 2016; 183:1055-62. [PMID: 27188949 DOI: 10.1093/aje/kwv283] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 10/13/2015] [Indexed: 11/12/2022] Open
Abstract
The use of pneumococcal conjugate vaccines (PCVs) in children has a strong indirect effect on disease rates in adults. When children are vaccinated with PCVs, other serotypes that are not targeted by the vaccine can increase in frequency (serotype replacement) and reduce the direct and indirect benefits of the vaccine. To understand and predict the likely impacts of serotype replacement, it is important to know how patterns in the transmission of serotypes among children relate to disease rates in adults. We used data on pneumococcal carriage and disease from Navajo Nation children and adults collected before and after the routine use of PCVs (1998-2012). Using regression models within a Bayesian framework, we found that serotype-specific carriage and invasiveness (disease incidence divided by carriage prevalence) had similar patterns in children and adults. Moreover, carriage in children, invasiveness in children, and a serotype-specific random intercept (which captured additional variation associated with the serotypes) could predict the incidence serotype-specific pneumococcal disease in adults 18-39 years of age and those 40 years of age or older in the era of routine use of PCVs. These models could help us predict the effects of future pneumococcal vaccine use in children on disease rates in adults, and the modeling approach developed here could be used to test these findings in other settings.
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Usuf E, Mackenzie G, Sambou S, Atherly D, Suraratdecha C. The economic burden of childhood pneumococcal diseases in The Gambia. COST EFFECTIVENESS AND RESOURCE ALLOCATION 2016; 14:4. [PMID: 26893592 PMCID: PMC4758012 DOI: 10.1186/s12962-016-0053-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 02/11/2016] [Indexed: 11/10/2022] Open
Abstract
Background Streptococcus pneumoniae is a common cause of child death. However, the economic burden of pneumococcal disease in low-income countries is poorly described. We aimed to estimate from a societal perspective, the costs incurred by health providers and families of children with pneumococcal diseases. Methods We recruited children less than 5 years of age with outpatient pneumonia, inpatient pneumonia, pneumococcal sepsis and bacterial meningitis at facilities in rural and urban Gambia. We collected provider costs, out of pocket costs and productivity loss for the families of children. For each disease diagnostic category, costs were collected before, during, and for 1 week after discharge from hospital or outpatient visit. Results A total of 340 children were enrolled; 100 outpatient pneumonia, 175 inpatient pneumonia 36 pneumococcal sepsis, and 29 bacterial meningitis cases. The mean provider costs per patient for treating outpatient pneumonia, inpatient pneumonia, pneumococcal sepsis and meningitis were US$8, US$64, US$87 and US$124 respectively and the mean out of pocket costs per patient were US$6, US$31, US$44 and US$34 respectively. The economic burden of outpatient pneumonia, inpatient pneumonia, pneumococcal sepsis and meningitis increased to US$15, US$109, US$144 and US$170 respectively when family members’ time loss from work was taken into account. Conclusion The economic burden of pneumococcal disease in The Gambia is substantial, costs to families was approximately one-third to a half of the provider costs, and accounted for up to 30 % of total societal costs. The introduction of pneumococcal conjugate vaccine has the potential to significantly reduce this economic burden in this society. Electronic supplementary material The online version of this article (doi:10.1186/s12962-016-0053-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Effua Usuf
- MRC, The Gambia Unit, PO Box 273, Banjul, Gambia
| | - Grant Mackenzie
- MRC, The Gambia Unit, PO Box 273, Banjul, Gambia ; Pneumococcal Group, Murdoch Children's Research Institute, Parkville, Australia ; Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | | | | | - Chutima Suraratdecha
- PATH, Seattle, USA ; U.S. Centers for Disease Control and Prevention, Atlanta, USA
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Rojas JP, Leal AL, Patiño J, Montañez A, Camacho G, Beltrán S, Bonilla C, Barrero R, Mariño C, Ramos N. [Characterization of patients who died of invasive pneumococcal disease in the child population of Bogota, Colombia]. ACTA ACUST UNITED AC 2015; 87:48-52. [PMID: 26627694 DOI: 10.1016/j.rchipe.2015.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 07/27/2015] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Streptococcus pneumoniae (S. pneumoniae), also known as pneumococcus, is one of the main bacteria associated with mortality in children under 2 years of age, with a morbidity and mortality incidence that varies according to demographics and exposure to risk, or protective factors. OBJECTIVE To describe the child mortality due to invasive pneumococcal disease (IPD) between 2008 -2014 (6 years), in 8 Medical Centres in Bogotá, Colombia. PATIENTS AND METHOD Descriptive observational case series of patients who died of IPD, aged 28 days to 18 years, in 8 tertiary care institutions in Bogota, Colombia. The study period was from 1 January 2008 to 15 January 2014. SAMPLE SIZE 239 patients. RESULTS A total of 239 registered cases of IPD were reviewed, showing a mortality of 8% (n 18). The mean age of patients that died was 43.7 months, with an age range from 2 to 176 months (14 years), with 66% of the cases being male. Serotypes were identified in 8 patients, finding: 6A, 6B, 10A, 14, 18C, 23B, 23F, and 35B. The most common clinical presentation of the cases was meningitis with mortality of 33% (6 cases), followed by bacteraemia without focus in 28% (5 cases), and pneumonia with 27% (5 cases). Combined clinical situations were presented, such as pneumonia and meningitis in 11% (2 cases). Two of the patients had clearly documented risk factors for IPD (asplenia and chronic respiratory disease). CONCLUSIONS IPD mortality is particularly high in children under 2 years in male patients, especially when presented with a meningeal focus (44%). Serotyping was not possible in all patients who died, since no strain isolated was sent to the National Institute of Health. Continuous and systematic vigilance is required to evaluate the impact of vaccination and possible changes in the pattern of presentation of disease.
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Affiliation(s)
- Juan Pablo Rojas
- Infectología Pediátrica, Universidad El Bosque, Fundación Cardioinfantil IC , Bogotá, Colombia.
| | - Aura Lucia Leal
- Universidad Nacional de Colombia, Asociación Colombiana de Infectología (ACIN), Grupo para el Control de la Resistencia Bacteriana en Bogotá, Grupo Neumocolombia, Colombia
| | - Jaime Patiño
- Fundación Cardioinfantil, Asociación Colombiana de Infectología ACIN-Sociedad Colombiana de Pediatría, Grupo Neumocolombia, Colombia
| | - Anita Montañez
- Asociación Colombiana de Infectología, Grupo Neumocolombia, Colombia
| | - Germán Camacho
- Hospital de la Misericordia, Universidad Nacional de Colombia. Grupo Neumocolombia, Colombia
| | - Sandra Beltrán
- Fundación Sanitas-Clínica Colombia, Grupo Neumocolombia, Colombia
| | | | - Rocio Barrero
- Hospital Santa Clara E.S.E y Hospital el Tunal E.S.E. Grupo Neumocolombia, Colombia
| | - Cristina Mariño
- Hospital Militar Central, Grupo Neumocolombia, Sociedad Colombiana de Pediatría, Colombia
| | - Nicolás Ramos
- Clínica El Bosque, Grupo Neumocolombia, Sociedad Colombiana de Pediatría, Colombia
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Vajer P, Tamás F, Urbán R, Torzsa P, Kalabay L. [Pneumococcal vaccination in general practice]. Orv Hetil 2015; 156:186-91. [PMID: 25618860 DOI: 10.1556/oh.2015.30054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
INTRODUCTION The prevalence of invasive pneumococcal disease, which is depending on risk factors and comorbidities, is increasing over the age of 50 years. Most developed countries have recommendations but vaccination rates remain low. AIM To assess the general practitioners' daily practice in relation to pneumococcal vaccination and analyse the effect of informing the subjects about the importance of pneumococcal vaccination on vaccination routine. METHOD Subjects over 50 years of age vaccinated against influenza during the 2012/2013 campaign were informed about the importance of pneumococcal vaccination and asked to fill in a questionnaire. RESULTS Of the 4000 subjects, 576 asked for a prescription of pneumococcal vaccine (16.5% of females and 11.6% of males, OR 1.67 CI 95% 1.37-2.04, p<0.001) and 310 were vaccinated. The mean age of females and males was 70.95 and 69.8 years, respectively (OR 1.01; CI 95% 1.00-1.02; p<0.05). Information given by physicians resulted in 33,6% prescription rate, while in case it was 8% when nurses provided information (OR 6.33; CI 95% 5.23-7.67; p<0.001). As an effect of this study the vaccination rate was 6.3 times higher than in the previous year campaign (p<0.001). CONCLUSIONS General practitioners are more effective in informing subjects about the importance of vaccination than nurses. Campaign can raise the vaccination rate significantly.
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Affiliation(s)
- Péter Vajer
- Semmelweis Egyetem, Általános Orvostudományi Kar Családorvosi Tanszék Budapest Kútvölgyi út 4. 1125
| | - Ferenc Tamás
- Semmelweis Egyetem, Általános Orvostudományi Kar Családorvosi Tanszék Budapest Kútvölgyi út 4. 1125
| | - Róbert Urbán
- Eötvös Loránd Tudományegyetem, PPK Személyiség- és Egészségpszichológiai Tanszék Budapest
| | - Péter Torzsa
- Semmelweis Egyetem, Általános Orvostudományi Kar Családorvosi Tanszék Budapest Kútvölgyi út 4. 1125
| | - László Kalabay
- Semmelweis Egyetem, Általános Orvostudományi Kar Családorvosi Tanszék Budapest Kútvölgyi út 4. 1125
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Méndez-Lage S, Losada-Castillo I, Agulla-Budiño A. [Streptococcus pneumoniae: serotype distribution, antimicrobial susceptibility, risk factors and mortality in Galicia over a two year-period]. Enferm Infecc Microbiol Clin 2015; 33:579-84. [PMID: 25726037 DOI: 10.1016/j.eimc.2015.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 01/13/2015] [Accepted: 01/15/2015] [Indexed: 11/25/2022]
Abstract
INTRODUCTION To examine the epidemiology of pneumococcal infection in Galicia (Spain) after the incorporation of the pneumococcal conjugate vaccine, and to determine serotype distribution, antibiotic susceptibility, risk factors and associated mortality in cases of invasive pneumococcal disease (IPD) during 2011 and 2012. METHODS All strains causing IPD in Galicia were studied. Serotyping was performed by agglutination and Quellung reaction. Antibiotic sensitivity to penicillin, cefotaxime, erythromycin, vancomycin, and levofloxacin was determined. The risk factors considered were chronic respiratory disease, heart disease, liver disease, kidney disease, diabetes mellitus, and HIV and non-HIV immunodeficiency. RESULTS A total of 555 strains were collected, with 43 different serotypes being found. The most frequently isolated ones were: serotype3 (17.5%), serotype7F (12.6%), serotype19A (9.4%), serotype14 (4.1%), serotype6C (4.1%), serotype11A (4%) and serotype22F (3.8%). 57.1% of isolates were serotypes included in VNC-13V. Two non-penicillin-sensitive strains and two others were not sensitive to cefotaxime, and 24.7% of the strains were not susceptible to erythromycin (26.9% in 2011 and 22.5% in 2012). The case fatality rate was 16.5%, reaching 23.3% in patients over 75years. Diseases with a statistically significant risk of mortality were: liver, kidney and immunodeficiency without HIV. CONCLUSIONS Serotype3 was the most frequent in Galicia. Very few strains were not susceptible to penicillin. Erythromycin resistance decreased from 2011 to 2012. It is highlighted that mortality increases with age. Liver disease, renal disease and non-HIV immunodeficiency increases the mortality risk.
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Affiliation(s)
- Susana Méndez-Lage
- Servicio de Microbiología, Complexo Hospitalario de Ferrol, Ferrol, A Coruña, España
| | - Isabel Losada-Castillo
- Servicio de Epidemioloxía, Dirección Xeral de Innovación e Xestión da Saúde Pública, Santiago de Compostela, A Coruña, España
| | - Andrés Agulla-Budiño
- Servicio de Microbiología, Complexo Hospitalario de Ferrol, Ferrol, A Coruña, España.
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Streptococcus pneumoniae serotype 1 burden in the African meningitis belt: exploration of functionality in specific antibodies. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:404-12. [PMID: 25651921 DOI: 10.1128/cvi.00758-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Streptococcus pneumoniae serotype 1 (Sp1) constitutes an important cause of seasonal endemic meningitis in all age groups in the African meningitis belt. Despite a higher meningitis incidence, the Burkinabé population has an Sp1-specific antibody seroprevalence similar to that reported in the United Kingdom (UK). We aimed to establish whether the opsonophagocytic activity (OPA) of pneumococcal IgG naturally present in Burkina Faso differs from that seen in individuals in the UK and to compare the OPAs generated by natural and vaccine-induced immunity. Samples collected from pneumococcal vaccine-naive Burkinabé and UK subjects were matched for age (1 to 39 years) and anti-Sp1 IgG level, analyzed for OPA to 3 S. pneumoniae serotypes (1, 5, and 19A), and compared to postvaccine samples. Furthermore, the Burkinabé samples were assessed for IgG avidity and serotype-specific IgM concentrations. One hundred sixty-nine matched serum samples from both populations were selected. A greater proportion of Burkinabé subjects aged 1 to 19 years had functional Sp1 activity (OPA ≥ 8) compared to UK subjects (12% versus 2%, P < 0.001); however, the proportions were similar among adults (9%). The correlation between Sp1 IgG concentration and OPA was good (P < 0.001), but many individuals had nonfunctional IgG, which was not related to avidity. While the Sp1 IgM concentrations correlated with OPA, not all of the function in serum samples with low IgG could be attributed to IgM. Finally, vaccine-induced Sp1-specific IgG was more functional than equivalent amounts of naturally occurring IgG. In conclusion, despite a substantially higher pneumococcal meningitis incidence, no decreased functional immunity to Sp1 could be evidenced in the Burkinabé population compared to that in the population from the UK. Furthermore, the naturally induced antibodies were less functional than vaccine-induced antibodies.
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Hamaluba M, Kandasamy R, Ndimah S, Morton R, Caccamo M, Robinson H, Kelly S, Field A, Norman L, Plested E, Thompson BAV, Zafar A, Kerridge SA, Lazarus R, John T, Holmes J, Fenlon SN, Gould KA, Waight P, Hinds J, Crook D, Snape MD, Pollard AJ. A cross-sectional observational study of pneumococcal carriage in children, their parents, and older adults following the introduction of the 7-valent pneumococcal conjugate vaccine. Medicine (Baltimore) 2015; 94:e335. [PMID: 25569650 PMCID: PMC4602851 DOI: 10.1097/md.0000000000000335] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Using nasopharyngeal carriage as a marker of vaccine impact, pneumococcal colonization and its relation to invasive disease were examined in children, their parents, and older adults in the United Kingdom following introduction of 7-valent pneumococcal conjugate vaccine (PCV7) and prior to 13-valent pneumococcal conjugate vaccine (PCV13).A cross-sectional observational study was conducted, collecting nasopharyngeal swabs from children aged 25 to 55 months who had previously received 3 doses of PCV7, their parents, and adults aged ≥65 years. Pneumococcal serotyping was conducted according to World Health Organization guidelines with nontypeable isolates further analyzed by molecular serotyping. A national invasive disease surveillance program was conducted throughout the corresponding period.Pneumococcus was isolated from 47% of children, 9% of parents, and 2.2% of older adults. For these groups, the percentage of serotypes covered by PCV7 were 1.5%, 0.0%, and 15.4%, with a further 20.1%, 44.4%, and 7.7% coverage added by those in PCV13. In each group, the percentage of disease due to serotypes covered by PCV7 were 1.0%, 7.4% and 5.1% with a further 65.3%, 42.1%, and 61.4% attributed to those in PCV13.The prevalence of carriage is the highest in children, with direct vaccine impact exemplified by low carriage and disease prevalence of PCV7 serotypes in vaccinated children, whereas the indirect effects of herd protection are implied by similar observations in unvaccinated parents and older adults.
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Affiliation(s)
- Mainga Hamaluba
- From the Oxford Vaccine Group (MH, RK, SN, MC, HR, SK, AF, LN, EP, SAK, RL, TJ, MDS, AJP), Department of Paediatrics, University of Oxford, and the NIHR Oxford Biomedical Research Centre, Oxford; Guy's and St Thomas' National Health Service Foundation Trust (RM), London; Department of Primary Healthcare Sciences (BAVT), University of Oxford, Oxford; Northamptonshire Teaching Primary Care Trust (AZ), National Health Service, Northamptonshire; Centre for Statistics in Medicine (JH), University of Oxford, Oxford; Health Protection Services (PW), Public Health England; Division of Clinical Sciences (SNF, KAG, JH), St. George's University of London, London; and Nuffield Department of Clinical Medicine (DC), University of Oxford, Oxford, UK
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Jiang Y, Gauthier A, Keeping S, Carroll S. Cost-effectiveness of vaccinating the elderly and at-risk adults with the 23-valent pneumococcal polysaccharide vaccine or 13-valent pneumococcal conjugate vaccine in the UK. Expert Rev Pharmacoecon Outcomes Res 2014; 14:913-27. [PMID: 25189087 DOI: 10.1586/14737167.2014.950232] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE The introduction of routine childhood vaccination with pneumococcal conjugate vaccines (PCVs) has led to a decrease in the overall incidence of pneumococcal disease in all ages and a change in the serotype distribution of the remaining disease. This study assessed the cost-effectiveness of vaccinating ≥65 years and at risk adults with either the 23-valent pneumococcal polysaccharide vaccine (PPV23) or the 13-valent conjugate vaccine (PCV13) in the UK, accounting for epidemiological changes. METHODS A population-based Markov model was used to track one UK-based cohort of individuals assuming PPV23, PCV13 or no vaccination until death. RESULTS The ICER was estimated at £8413 when PPV23 was compared to no vaccination. PPV23 dominated PCV13. CONCLUSION This model suggests that vaccinating with PPV23 is cost-effective when compared to both PCV13 and no vaccination. As PPV23 covers 80-90% in the UK of all serotypes causing invasive pneumococcal diseases, it remains cost-effective despite recent reductions in invasive pneumococcal diseases incidence in adults.
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Affiliation(s)
- Yiling Jiang
- Amaris, The Fitzpatrick Building 188 York Way, London N7 9AS, UK
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Jiang Y, Gauthier A, Keeping S, Carroll S. A public health and budget impact analysis of vaccinating the elderly and at-risk adults with the 23-valent pneumococcal polysaccharide vaccine or 13-valent pneumococcal conjugate vaccine in the UK. Expert Rev Pharmacoecon Outcomes Res 2014; 14:901-11. [PMID: 25186657 DOI: 10.1586/14737167.2014.953932] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Since the introduction of the routine childhood immunization, a change in epidemiology of pneumococcal disease has been seen in both children and adults. This study aimed to quantify the public health and budget impact of pneumococcal vaccination of the elderly and those in at risk groups in the UK. METHODS The model was adapted from a previous population-based Markov model. At-risk adults and the elderly were assumed to receive PPV23 or PCV13 vaccination or no vaccination. RESULTS Over the study period (2012-2016), PPV23 vaccination led to a reduction in the number of invasive pneumococcal disease cases in most scenarios. The net budget impact ranged between £15 and £39 million (vs no vaccination) or between -£116 and -£93 million (vs PCV13). CONCLUSION PPV23 vaccination program remains the optimal strategy from public health and budgetary perspectives despite epidemiological changes. PCV13 is likely to impose a significant budget with limited health benefits.
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Affiliation(s)
- Yiling Jiang
- Amaris, The Fitzpatrick Building, 188 York Way, London N7 9AS, UK
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Martikainen JA, Soini EJ, Laine J, Ahman H, Postila V, Klemets P. Economic impact of 13-valent pneumococcal conjugate vaccine in Finnish adults ≥50 years with underlying chronic medical conditions. J Eval Clin Pract 2014; 20:333-41. [PMID: 24813690 DOI: 10.1111/jep.12131] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/27/2014] [Indexed: 12/01/2022]
Abstract
RATIONALE, AIMS AND OBJECTIVES Invasive pneumococcal diseases (IPD) are associated with substantial burden in adults (≥50 years). Moreover, adults with vascular, metabolic or respiratory diseases have been shown to have a 3-6 times higher risk of IPD when compared with their healthy controls. These persons at higher risk are likely to benefit most from pneumococcal vaccinations. The 13-valent pneumococcal conjugate vaccine (PCV13) was recently introduced to prevent the 13 most prevalent serotypes causing invasive pneumococcal disease in adults. The objective of this study was to estimate the expected 5-year economic impact of targeted PCV13 vaccination compared with no vaccination in Finnish adults (≥50 years) at moderate or high risk for IPD. METHODS A budget impact model was developed to predict the impact of PCV13 vaccination in terms of the costs and IPD events avoided for years 2012-2016. RESULTS Approximately 35% of the 2.2 million Finns over 50 years of age can be considered to be at moderate or high risk for IPD because of underlying chronic medical conditions. Vaccination of these people with PCV13 could provide an estimated net budget savings of about €218 million compared with the current no-vaccination situation over the next 5 years. Among the risk groups considered, the largest absolute net savings (€66.2 million) could be expected to be obtained by vaccinating people with heart disease, due to its high prevalence in the target population. CONCLUSION In Finland, the immunization with PCV13 vaccine, of adults (≥50 years) at moderate and high risk of IPD, is estimated to lead to substantial cost savings in the 5 years after vaccination.
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Martin NG, Sadarangani M, Pollard AJ, Goldacre MJ. Hospital admission rates for meningitis and septicaemia caused by Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae in children in England over five decades: a population-based observational study. THE LANCET. INFECTIOUS DISEASES 2014; 14:397-405. [DOI: 10.1016/s1473-3099(14)70027-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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van Hoek AJ, Sheppard CL, Andrews NJ, Waight PA, Slack MPE, Harrison TG, Ladhani SN, Miller E. Pneumococcal carriage in children and adults two years after introduction of the thirteen valent pneumococcal conjugate vaccine in England. Vaccine 2014; 32:4349-55. [PMID: 24657717 DOI: 10.1016/j.vaccine.2014.03.017] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 02/28/2014] [Accepted: 03/05/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND/AIMS In April 2010 the 7-valent pneumococcal conjugate vaccine (PCV7) was replaced by the 13-valent PCV. We investigated pneumococcal carriage in children eligible for PCV7 or PCV13 and their household contacts. METHODS Eligible families in Hertfordshire and Gloucester were identified and a nasopharyngeal swab obtained from consenting household members between July 2012 and March 2013. Samples were cultured for Streptococcus pneumoniae and serotyped by standard methods. For each serotype the ratio of its prevalence in invasive pneumococcal disease (IPD) to its carriage prevalence (case:carrier ratio, CCR) was calculated. Results were compared with previous carriage studies in 2001/2002 and 2008/2009, before and after PCV7 introduction. RESULTS 217 households were included. Among <5-year olds 47.7% (95% confidence interval 41.8-53.5) were carrying a pneumococcus compared with 51.0% (95% CI: 44.0-58.0) in 2008/2009 and 48.4% (95% CI: 44.1-52.7) in 2001/2002. The odds of carrying a PCV7 serotype was significantly reduced in 2008/2009 (0.07, 95% CI: 0.03-0.16) and 2012/2013 (0.01 95% CI: 0.00-0.07) relative to 2001/2002, while the odds of carrying any of the extra six PCV13 serotypes increased after PCV7 introduction (1.38, 95%CI: 0.73-2.59) but declined significantly after PCV13 introduction (0.05, 95%CI: 0.01-0.37). The CCRs for the frequently carried serotypes were relatively low, with the highest CCR observed for serotypes 7F, 19A, 3, 8, and 33F. Across the three carriage studies, CCR estimates were stable for nearly all serotypes. CONCLUSION Carriage of additional PCV13 serotypes has rapidly reduced post-PCV13 introduction in both vaccinated and unvaccinated individuals with a continued decline in transmission of PCV7 serotypes. Carriage rates in children remain unchanged, but the low CCRs of replacing serotypes would be expected to further reduce overall IPD across all age groups.
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Affiliation(s)
- Albert Jan van Hoek
- Immunisation, Hepatitis and Blood Safety Department, Public Health England, London NW9 5EQ, England, United Kingdom.
| | - Carmen L Sheppard
- Respiratory & Vaccine Preventable Bacteria Reference Unit, Public Health England, London NW9 5EQ, England, United Kingdom
| | - Nick J Andrews
- Immunisation, Hepatitis and Blood Safety Department, Public Health England, London NW9 5EQ, England, United Kingdom
| | - Pauline A Waight
- Immunisation, Hepatitis and Blood Safety Department, Public Health England, London NW9 5EQ, England, United Kingdom
| | - Mary P E Slack
- Respiratory & Vaccine Preventable Bacteria Reference Unit, Public Health England, London NW9 5EQ, England, United Kingdom
| | - Timothy G Harrison
- Respiratory & Vaccine Preventable Bacteria Reference Unit, Public Health England, London NW9 5EQ, England, United Kingdom
| | - Shamez N Ladhani
- Immunisation, Hepatitis and Blood Safety Department, Public Health England, London NW9 5EQ, England, United Kingdom
| | - Elizabeth Miller
- Immunisation, Hepatitis and Blood Safety Department, Public Health England, London NW9 5EQ, England, United Kingdom
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Le Polain de Waroux O, Flasche S, Prieto-Merino D, Edmunds WJ. Age-dependent prevalence of nasopharyngeal carriage of streptococcus pneumoniae before conjugate vaccine introduction: a prediction model based on a meta-analysis. PLoS One 2014; 9:e86136. [PMID: 24465920 PMCID: PMC3900487 DOI: 10.1371/journal.pone.0086136] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 12/04/2013] [Indexed: 11/18/2022] Open
Abstract
Introduction Data on the prevalence of nasopharyngeal carriage of S.pneumoniae in all age groups are important to help predict the impact of introducing pneumococcal conjugate vaccines (PCV) into routine infant immunization, given the important indirect effect of the vaccine. Yet most carriage studies are limited to children under five years of age. We here explore the association between carriage prevalence and serotype distribution in children aged ≥5 years and in adults compared to children. Methods We conducted a systematic review of studies providing carriage estimates across age groups in healthy populations not previously exposed to PCV, using MEDLINE and Embase. We used Bayesian linear meta-regression models to predict the overall carriage prevalence as well as the prevalence and distribution of vaccine and nonvaccine type (VT and NVT) serotypes in older age groups as a function of that in <5 y olds. Results Twenty-nine studies compromising of 20,391 individuals were included in the analysis. In all studies nasopharyngeal carriage decreased with increasing age. We found a strong positive linear association between the carriage prevalence in pre-school childen (<5 y) and both that in school aged children (5–17 y olds) and in adults. The proportion of VT serotypes isolated from carriers was consistently lower in older age groups and on average about 73% that of children <5 y among 5–17 y olds and adults respectively. We provide a prediction model to infer the carriage prevalence and serotype distribution in 5–17 y olds and adults as a function of that in children <5 years of age. Conclusion Such predictions are helpful for assessing the potential population-wide effects of vaccination programmes, e.g. via transmission models, and thus assist in the design of future pneumococcal conjugate vaccination strategies.
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Affiliation(s)
- Olivier Le Polain de Waroux
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Stefan Flasche
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David Prieto-Merino
- Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - W. John Edmunds
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Usuf E, Bottomley C, Adegbola RA, Hall A. Pneumococcal carriage in sub-Saharan Africa--a systematic review. PLoS One 2014; 9:e85001. [PMID: 24465464 PMCID: PMC3896352 DOI: 10.1371/journal.pone.0085001] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 11/28/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Pneumococcal epidemiology varies geographically and few data are available from the African continent. We assess pneumococcal carriage from studies conducted in sub-Saharan Africa (sSA) before and after the pneumococcal conjugate vaccine (PCV) era. METHODS A search for pneumococcal carriage studies published before 2012 was conducted to describe carriage in sSA. The review also describes pneumococcal serotypes and assesses the impact of vaccination on carriage in this region. RESULTS Fifty-seven studies were included in this review with the majority (40.3%) from South Africa. There was considerable variability in the prevalence of carriage between studies (I-squared statistic = 99%). Carriage was higher in children and decreased with increasing age, 63.2% (95% CI: 55.6-70.8) in children less than 5 years, 42.6% (95% CI: 29.9-55.4) in children 5-15 years and 28.0% (95% CI: 19.0-37.0) in adults older than 15 years. There was no difference in the prevalence of carriage between males and females in 9/11 studies. Serotypes 19F, 6B, 6A, 14 and 23F were the five most common isolates. A meta-analysis of four randomized trials of PCV vaccination in children aged 9-24 months showed that carriage of vaccine type (VT) serotypes decreased with PCV vaccination; however, overall carriage remained the same because of a concomitant increase in non-vaccine type (NVT) serotypes. CONCLUSION Pneumococcal carriage is generally high in the African continent, particularly in young children. The five most common serotypes in sSA are among the top seven serotypes that cause invasive pneumococcal disease in children globally. These serotypes are covered by the two PCVs recommended for routine childhood immunization by the WHO. The distribution of serotypes found in the nasopharynx is altered by PCV vaccination.
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Affiliation(s)
- Effua Usuf
- Child Survival, Medical Research Council The Gambia Unit, Fajara, The Gambia
| | - Christian Bottomley
- Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Andrew Hall
- Faculty of Epidemiology and Public Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Rozenbaum MH, De Cao E, Westra TA, Postma MJ. Dynamic models for health economic assessments of pertussis vaccines: what goes around comes around…. Expert Rev Vaccines 2014; 11:1415-28. [DOI: 10.1586/erv.12.130] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Rozenbaum MH, Boersma C, Postma MJ, Hak E. Observed differences in invasive pneumococcal disease epidemiology after routine infant vaccination. Expert Rev Vaccines 2014; 10:187-99. [DOI: 10.1586/erv.10.163] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Grabenstein JD, Weber DJ. Pneumococcal serotype diversity among adults in various countries, influenced by pediatric pneumococcal vaccination uptake. Clin Infect Dis 2013; 58:854-64. [PMID: 24344141 DOI: 10.1093/cid/cit800] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Streptococcus pneumoniae serotypes differ in clinical manifestations among adults. Indirect effects of pediatric use of pneumococcal conjugate vaccines (PCVs) affect rates of adult serotype-specific invasive pneumococcal disease (IPD). To characterize PCV effect on adult serotype patterns, we reviewed the literature for differences in proportions and incidence matching the 23-valent pneumococcal polysaccharide vaccine (PPSV23) and 13-valent PCV within specified geographic and time conditions. For adult IPD serotype distribution before widespread pediatric PCV7 use, the median differential between the 23 and 13 serotypes was 16.3% in the core analysis. After pediatric PCV7 adoption, the median differential was 24.4% (P < .003).The median differential in IPD incidence among adults was 5.6 cases per 100 000 population before pediatric PCV7 use and 6.4 afterward (P = .52). The differential for the serotypes in alternate vaccines helps explain recent national recommendations for one or both vaccines in various populations. These differences may widen further, with more extensive pediatric uptake of higher-valence PCVs.
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Miyaji EN, Oliveira MLS, Carvalho E, Ho PL. Serotype-independent pneumococcal vaccines. Cell Mol Life Sci 2013; 70:3303-26. [PMID: 23269437 PMCID: PMC11113425 DOI: 10.1007/s00018-012-1234-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 12/01/2012] [Accepted: 12/04/2012] [Indexed: 12/14/2022]
Abstract
Streptococcus pneumoniae remains an important cause of disease with high mortality and morbidity, especially in children and in the elderly. The widespread use of the polysaccharide conjugate vaccines in some countries has led to a significant decrease in invasive disease caused by vaccine serotypes, but an increase in disease caused by non-vaccine serotypes has impacted on the overall efficacy of these vaccines on pneumococcal disease. The obvious solution to overcome such shortcomings would be the development of new formulations that provide serotype-independent immunity. This review focuses on the most promising approaches, including protein antigens, whole cell pneumococcal vaccines, and recombinant bacteria expressing pneumococcal antigens. The protective capacity of these vaccine candidates against the different stages of pneumococcal infection, including colonization, mucosal disease, and invasive disease in animal models is reviewed. Some of the human trials that have already been performed or that are currently ongoing are presented. Finally, the feasibility and the possible shortcomings of these candidates in relation to an ideal vaccine against pneumococcal infections are discussed.
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Affiliation(s)
- Eliane Namie Miyaji
- Centro de Biotecnologia, Instituto Butantan, Av Vital Brasil 1500, São Paulo, SP 05503-900 Brazil
| | | | - Eneas Carvalho
- Centro de Biotecnologia, Instituto Butantan, Av Vital Brasil 1500, São Paulo, SP 05503-900 Brazil
| | - Paulo Lee Ho
- Centro de Biotecnologia, Instituto Butantan, Av Vital Brasil 1500, São Paulo, SP 05503-900 Brazil
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Gil E, Noursadeghi M, Brown JS. The clinical and ecological impact of childhood pneumococcal vaccination. Br J Hosp Med (Lond) 2013; 74:212-6. [PMID: 23571392 DOI: 10.12968/hmed.2013.74.4.212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Eliza Gil
- Respiratory Medicine Department, University College, London, UK.
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Surewaard BGJ, Trzciński K, Jacobino SR, Hansen IS, Vughs MM, Sanders EAM, van der Ende A, van Strijp JAG, de Haas CJC. Pneumococcal immune evasion: ZmpC inhibits neutrophil influx. Cell Microbiol 2013; 15:1753-65. [PMID: 23601501 DOI: 10.1111/cmi.12147] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/21/2013] [Accepted: 04/04/2013] [Indexed: 12/24/2022]
Abstract
Neutrophil recruitment is essential in clearing pneumococcal infections. The first step in neutrophil extravasation involves the interaction between P-selectin on activated endothelium and P-Selectin Glycoprotein 1 (PSGL-1) on neutrophils. Here, we identify pneumococcal Zinc metalloproteinase C as a potent inhibitor of PSGL-1. ZmpC degrades the N-terminal domain of PSGL-1, thereby disrupting the initial rolling of neutrophils on activated human umbilical vein endothelial cells. Furthermore, mice infected with wild-type strain in the model of pneumococcal pneumonia showed lower lungs neutrophil infiltration compare to animals infected with ZmpC mutant. In addition, we confirmed the association of zmpC with serotype 8 and 11A and found it to be associated with serotype 33F as well. In conclusion, wereport PSGL-1 as a novel target for ZmpC and show that ZmpC inhibits neutrophil extravasation during pneumococcal pneumonia.
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Affiliation(s)
- Bas G J Surewaard
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
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Pradas R, Gil de Miguel A, Álvaro A, Gil-Prieto R, Lorente R, Méndez C, Guijarro P, Antoñanzas F. Budget impact analysis of a pneumococcal vaccination programme in the 65-year-old Spanish cohort using a dynamic model. BMC Infect Dis 2013; 13:175. [PMID: 23578307 PMCID: PMC3637288 DOI: 10.1186/1471-2334-13-175] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 04/01/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This study aimed to assess the costs and clinical benefits of the 13-valent pneumococcal conjugate vaccine (PCV13) administered annually to the 65-year-old cohort in Spain versus the alternative of not vaccinating patients and treating them only when infected. METHODS Cases of pneumococcal disease avoided were calculated through a dynamic model based on the work of Anderson and May (1999). Sixty-six percent of the 65-year-old cohort was assumed to have been vaccinated with one PCV13 dose (304,492 subjects). Base-case estimated vaccine effectiveness and serotype coverage were 58% and 60%, respectively. Disease-related costs were calculated based on published data. RESULTS Over the 5-year period, a total of 125,906 cases of pneumococcal disease would be avoided. Net savings of €102 million would be obtained. The cost-saving distribution was not homogeneous, starting in the 2nd year and increasing through the 5th. To demonstrate model robustness, an additional scenario analysis was performed using extreme values of model parameters (vaccination programme coverage, vaccine effectiveness, discount rate and disease costs). Under those scenarios, net savings were always achieved. CONCLUSIONS Based on the assumptions of the model, the 65-year-cohort pneumococcal vaccination campaign appears to be a cost-saving intervention in the Spanish population under different scenarios.
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Pneumococcal infection--low awareness as a potential barrier to vaccination: results of a European study. Adv Ther 2013; 30:387-405. [PMID: 23605248 DOI: 10.1007/s12325-013-0025-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Elderly people and adults with chronic disease or compromised immune status are at increased risk of pneumococcal infection, with pneumonia being the most common serious presentation and a significant cause of morbidity and mortality. Most European countries have recommendations for pneumococcal vaccination but vaccination rates have remained low. In the present article, the authors present the results of a European survey that investigated the current level of awareness of pneumococcal infection among primary care physicians and specialists, and attitudes to vaccination in these physicians and members of the general public aged >50 years. METHODS Primary care physicians (n = 1,300) and specialists (n = 926) from 13 Western European countries participated in online/face-to-face interviews, and a further 6,534 individuals aged >50 years from a population sample reflecting local socio-demographic structure participated in telephone/face-to-face interviews. RESULTS Pneumonia was the most well-known of the pneumococcal infections amongst primary care physicians and specialists. However, there was a relatively low awareness of the term invasive pneumococcal disease (IPD), with only 50% of primary care physicians and 71% of specialists reporting knowledge of the term IPD. Key factors influencing a physician's decision to prescribe pneumococcal vaccination were the patient's health condition, recommendations from health authorities, and the tolerability of the vaccine. Perceptions regarding vaccination were good amongst the members of the general public; individuals did not fear vaccines or their side effects. The main drivers for vaccination were recommendations from a healthcare professional and, to a lesser extent, that vaccination provides reassurance against contracting a disease. CONCLUSION These findings highlight the low awareness of the term IPD in comparison with individual pneumococcal conditions. Given the importance of physician recommendations in encouraging patients to be vaccinated, primary care physicians need to be vigilant of patients at risk of pneumococcal infections in order to increase vaccination rates.
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Regev-Yochay G, Rahav G, Strahilevitz J, Bishara J, Katzir M, Chowers M, Finkelstein R, Chazan B, Zimhony O, Dagan R. A nationwide surveillance of invasive pneumococcal disease in adults in Israel before an expected effect of PCV7. Vaccine 2013; 31:2387-94. [PMID: 23518404 DOI: 10.1016/j.vaccine.2013.02.059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 02/02/2013] [Accepted: 02/27/2013] [Indexed: 10/27/2022]
Abstract
Pneumococcal infections in adults vary in severity and incidence is affected by childhood vaccination policy. Here, we try to define the host determinants and the interaction with specific serotypes that result in invasive pneumococcal disease (IPD) before an expected effect of pneumococcal conjugate vaccines. A nationwide active surveillance was initiated on July 2009, at the time of national implementation of PCV7 in Israel. The surveillance included all 27 laboratories and medical centers performing blood cultures in Israel, providing all blood and CSF pneumococcal isolates from persons ≥18y. Capture-recapture method assured that >95% of all cases were reported. IPD outcome and medical history were recorded and isolates were serotyped. Four hundred and sixty IPD cases were reported (annual incidence [/100,000] of 9.25). Incidence increased with age, from 2.6 among 18-34y to 66.8 among ≥85y. The most common diagnosis was pneumonia (72.4%), followed by bacteremia with no apparent focus (20.2%). Case fatality rate increased with age and number of comorbidities (34.5% for ≥75y or those with ≥3 comorbidities vs. 9.2-11.2% among <65y or those with no comorbidities; p=0.015). Variables independently associated with mortality were: age ≥75, chronic renal failure, malignancy, neurosurgery, alcohol abuse, multi-lobar pneumonia and sepsis with no apparent focus. The predominant serotypes in patients 18-49y were 1, 5, 8, 7F and 9V (constituting 56.3% in this age-group vs. 11.9% in ≥75y; p<0.01). The predominant serotypes among patients ≥75y were 3, 19A, 23F and 14 (40.3% of this age-group vs. 12.9% of 18-49y; p<0.01). Overall, PCV7 and PCV13 covered 25.6% and 63.7% of isolates, respectively, and 30.9% and 67.9% of isolates in mortality cases respectively. This nationwide active surveillance provides the baseline incidence, mortality rates and risk group distributions of IPD in adults before expected PCV effect.
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Affiliation(s)
- Gili Regev-Yochay
- Infectious Disease Unit, Sheba Medical Center, Ramat-Gan, Israel, Affiliated to the Sackler School of Medicine, Tel-Aviv University, Israel.
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Nicoli EJ, Trotter CL, Turner KME, Colijn C, Waight P, Miller E. Influenza and RSV make a modest contribution to invasive pneumococcal disease incidence in the UK. J Infect 2013; 66:512-20. [PMID: 23473714 PMCID: PMC3650581 DOI: 10.1016/j.jinf.2013.02.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 02/01/2013] [Accepted: 02/06/2013] [Indexed: 11/18/2022]
Abstract
Objectives The common seasonality of incidence of invasive pneumococcal disease (IPD) and viral respiratory infections has long been recognized, however, the extent to which this affects the association between the pathogens is unknown. We have analysed weekly surveillance data of IPD, influenza and respiratory syncytial virus (RSV), using ambient temperature and hours of sunshine as measures of seasonality. Methods Reported cases of influenza, IPD and RSV, were collected in England and Wales, from week 1 (January) 1996 to week 23 (June) 2009. The associations between IPD and respiratory viral infections were analysed using several statistical methods, including correlation coefficients and both additive and multiplicative regression models. Results 6–7.5% of cases of IPD are attributable to influenza and 3–4% attributable to RSV. Correlation coefficients reported considerably stronger associations between IPD and the viral infections compared to regression models. Conclusions A small but potentially important percentage of IPD may be attributable to influenza and RSV when adjusted for seasonality by temperature. Jointly these viral infections may lead to over 10% of IPD cases. Therefore, prevention of viral respiratory infections may offer some additional benefit in reducing invasive pneumococcal infections.
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Affiliation(s)
- Emily J Nicoli
- School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
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Ladhani SN, Andrews NJ, Waight P, Borrow R, Slack MPE, Miller E. Impact of the 7-valent pneumococcal conjugate vaccine on invasive pneumococcal disease in infants younger than 90 days in England and wales. Clin Infect Dis 2012; 56:633-40. [PMID: 23175560 DOI: 10.1093/cid/cis934] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae is an uncommon but well-recognized cause of invasive bacterial disease in young infants. This study aimed to determine the impact of the 7-valent pneumococcal conjugate vaccine (PCV7) on invasive pneumococcal disease (IPD) in infants aged <90 days in England and Wales and describe their clinical characteristics following PCV7 introduction. METHODS Trends in IPD among infants aged <90 days during 1998-1999 through 2009-2010 were analyzed using enhanced national surveillance data. Following PCV7 introduction, clinical information was also obtained for IPD cases in the birth cohorts eligible for vaccination. RESULTS Prior to PCV7 introduction, IPD incidence in infants aged <90 days was 13.0 (95% confidence interval [CI], 12.0-14.0) per 100 000 live births and PCV7 serotypes accounted for 44% (154/349) of serotyped isolates. PCV7 introduction resulted in 83% (95% CI, 66%-91%, P < .001) reduction in PCV7 IPD and a declining trend in overall IPD by 2009-2010. Of the 256 cases diagnosed after PCV7 introduction, 23% (n = 60) had been born before 37 weeks' gestation. A third of cases (84/256, 33%) developed IPD in the first 48 hours of life, where 42% (35/84) were premature. Meningitis was diagnosed in 94 infants (37%) and its prevalence increased with age. Case fatality was 7% (18/256) and was higher for meningitis than nonmeningitis cases (adjusted odds ratio, 3.8 [95% CI, 1.2-12.0], P = .024). CONCLUSIONS Young infants have benefited from PCV7 through indirect (herd) protection. Given that a third of cases occurred within 48 hours of birth, further studies should focus on risk factors for IPD in pregnancy and strategies to prevent mother-to-child transmission.
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Affiliation(s)
- Shamez N Ladhani
- Health Protection Services Colindale, Health Protection Agency, Manchester Royal Infirmary, Manchester, United Kingdom.
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Streptococcus pneumoniae capsular serotype invasiveness correlates with the degree of factor H binding and opsonization with C3b/iC3b. Infect Immun 2012; 81:354-63. [PMID: 23147038 DOI: 10.1128/iai.00862-12] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Different capsular serotypes of Streptococcus pneumoniae vary markedly in their ability to cause invasive infection, but the reasons why are not known. As immunity to S. pneumoniae infection is highly complement dependent, variations in sensitivity to complement between S. pneumoniae capsular serotypes could affect invasiveness. We have used 20 capsule-switched variants of strain TIGR4 to investigate whether differences in the binding of the alternative pathway inhibitor factor H (FH) could be one mechanism causing variations in complement resistance and invasive potential between capsular serotypes. Flow cytometry assays were used to assess complement factor binding and complement-dependent neutrophil association for the TIGR4 capsule-switched strains. FH binding varied with the serotype and inversely correlated with the results of factor B binding, C3b/iC3b deposition, and neutrophil association. Differences between strains in FH binding were lost when assays were repeated with pspC mutant strains, and loss of PspC also reduced differences in C3b/iC3b deposition between strains. Median FH binding was high in capsule-switched mutant strains expressing more invasive serotypes, and a principal component analysis demonstrated a strong correlation between serotype invasiveness, high FH binding, and resistance to complement and neutrophil association. Further data obtained with 33 clinical strains also demonstrated that FH binding negatively correlated with C3b/iC3b deposition and that median FH binding was high in strains expressing more invasive serotypes. These data suggest that variations in complement resistance between S. pneumoniae strains and the association of a serotype with invasiveness could be related to capsular serotype effects on FH binding.
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Rozenbaum MH, van Hoek AJ, Fleming D, Trotter CL, Miller E, Edmunds WJ. Vaccination of risk groups in England using the 13 valent pneumococcal conjugate vaccine: economic analysis. BMJ 2012; 345:e6879. [PMID: 23103369 PMCID: PMC3482156 DOI: 10.1136/bmj.e6879] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To estimate the cost effectiveness of vaccinating people with high risk conditions against invasive pneumococcal disease using the 13 valent pneumococcal conjugate vaccine. DESIGN Economic evaluation using a cohort model from the perspective of healthcare providers. SETTING England. PARTICIPANTS People aged 2 years and older at increased risk of invasive pneumococcal disease due to chronic kidney disease; splenic dysfunction; HIV infection; a compromised immune system; chronic heart, liver, or respiratory disease; or diabetes. MAIN OUTCOME MEASURES Costs, gains in life years and quality adjusted life years (QALYs), and incremental cost effectiveness ratios. RESULTS Increasing indirect protection resulting from the vaccination programme of infants using the 13 valent pneumococcal conjugate vaccine means that the burden of disease preventable by targeting high risk groups will diminish in time. Under base case assumptions--that is, no overall impact on non bacteraemic pneumonia in high risk groups and assuming the high risk vaccination programme would be launched two to three years after the infant programme--the incremental cost effectiveness ratio was estimated to be more than £30,000 (€37,216; $48,210) per QALY gained for most risk groups. If, however, the vaccine does not offer protection against non-bacteraemic pneumococcal pneumonia or the vaccine was introduced concomitantly with the infant 13 valent pneumococcal conjugate vaccination programme then vaccinating high risk people would (more) likely be cost effective. Sensitivity analyses showed that the cost effectiveness was particularly sensitive to assumed herd benefits and vaccine efficacy estimates. CONCLUSION Under base case assumptions it is unlikely that a pneumococcal vaccination programme aimed at risk groups could be considered cost effective. Uncertainty could be substantially reduced by establishing the effectiveness of the 13 valent pneumococcal conjugate vaccine against non-bacteraemic pneumococcal pneumonia, particularly in at risk groups.
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Affiliation(s)
- Mark H Rozenbaum
- Unit of PharmacoEpidemiology and PharmacoEconomics, Department of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, Netherlands.
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Jiang Y, Gauthier A, Annemans L, van der Linden M, Nicolas-Spony L, Bresse X. Cost-effectiveness of vaccinating adults with the 23-valent pneumococcal polysaccharide vaccine (PPV23) in Germany. Expert Rev Pharmacoecon Outcomes Res 2012; 12:645-60. [PMID: 23025422 DOI: 10.1586/erp.12.54] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The introduction of routine infant vaccination against pneumococcal disease has resulted in a decreased overall invasive pneumococcal disease incidence in adults but also a change in invasive pneumococcal disease serotypes. This study aimed to assess the cost-effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPV23) in Germany in this context. A population-based Markov model was developed. A cohort of adults currently eligible for vaccination was followed until death. Adult vaccination with PPV23 was associated with an incremental cost-effectiveness ratio of €17,065/quality-adjusted life years gained from the third-party payer's perspective. Univariate sensitivity analyses showed that the incremental cost-effectiveness ratio was below €50,000/quality-adjusted life years gained in most test scenarios. The model suggests that adult PPV23 vaccination is cost effective in Germany, due to its broad serotype coverage. This is despite epidemiological changes in Streptococcus pneumoniae serotypes caused by wider use of pneumococcal conjugate vaccines during childhood.
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Jiang Y, Gauthier A, Annemans L, van der Linden M, Nicolas-Spony L, Bresse X. A public health and budget impact analysis of vaccinating at-risk adults and the elderly against pneumococcal diseases in Germany. Expert Rev Pharmacoecon Outcomes Res 2012; 12:631-43. [PMID: 23025421 DOI: 10.1586/erp.12.55] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To assess the comparative public health and budget impact over 5 years of several pneumococcal vaccination strategies (23-valent pneumococcal polysaccharide vaccine [PPV23] and/or 13-valent pneumococcal conjugate vaccine [PCV13]) in Germany, within the context of changing invasive pneumococcal disease (IPD) incidence over time. A multi-cohort, population-based Markov model was developed. Uncertainty around vaccine effectiveness, costs and IPD incidence change was handled through scenario analyses. Between 2012 and 2016, the introduction of PCV13 in adults, compared with the use of PPV23, would be associated with a net estimated budget increase of €59.7 million (+6.7%) to €151.6 million (+13.7%). Impact on IPD incidence ranged from -113 cases (-0.8%) to +298 cases (+2.8%). Introducing PCV13 in adults is expected to significantly affect healthcare budgets. Adult vaccination with PPV23 remains the optimal vaccination strategy from public health and budget perspectives.
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Andrews NJ, Waight PA, George RC, Slack MPE, Miller E. Impact and effectiveness of 23-valent pneumococcal polysaccharide vaccine against invasive pneumococcal disease in the elderly in England and Wales. Vaccine 2012; 30:6802-8. [PMID: 23000122 DOI: 10.1016/j.vaccine.2012.09.019] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/20/2012] [Accepted: 09/07/2012] [Indexed: 10/27/2022]
Abstract
In 2003 the existing 23-valent pneumococcal vaccine (PPV23) programme for high risk groups was extended to include all ≥ 65 year olds in England and Wales, starting with ≥ 80 year olds and moving to 75-79 and 65-74 year olds by 2005. We conducted an ecological study to assess the impact of the extended PPV23 programme on serotype-specific incidence of invasive pneumococcal disease (IPD) and a case-control study to assess vaccine effectiveness (VE) using the national IPD surveillance dataset. Between 1998 and 2006 IPD incidence caused by PPV23 serotypes in the targeted age-groups was unchanged. IPD caused by the serotypes covered by the 7-valent conjugate vaccine (PCV7) introduced for children in 2006 declined in ≥ 65 year olds after 2006 but was offset by an increase in non-PCV7 serotypes. This increase was similar for the additional 16 serotypes covered by PPV23 and the non-PPV23 serotypes. For the VE study, vaccine history was obtained for controls (n=1270) with non-PPV23 IPD diagnosed between November 2003 and December 2010 and a subset of cases (n=1272) matched for age and time period. VE declined from 48% (95% confidence interval; 32-60%) within two years of vaccination to 15% (-3% to 30%) after five years. Although differences in VE by age and having risk conditions were not statistically significant the highest estimates were in the youngest age group (65-74 years) and in those without risk conditions with a VE estimate of 65% (23-84%) within 2 years of vaccination for non-risk 65-74 year olds. VE differed by serotype (p=0.005), from -23% (-85% to 19%) for serotype 3 to 63% (29-81%) for 12F. In conclusion PPV23 was effective, particularly in healthy under 75 year olds, but protection waned after 5 years. There was no discernible impact of PPV23 on IPD incidence or PCV7-induced serotype replacement, consistent with the modest overall effectiveness, the 45% increased coverage over the former risk-based programme and lack of herd immunity from the PPV23 programme. Based on the VE estimates PPV23 was still considered a cost-effective intervention for the low risk elderly.
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Affiliation(s)
- Nick J Andrews
- Statistics, Modelling and Economics Department, Health Protection Services, Health Protection Agency, London, United Kingdom.
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Cohen R, Levy C, Bingen E, Bechet S, Derkx V, Werner A, Koskas M, Varon E. [Nasopharyngeal carriage of children 6 to 60 months during the implementation of the 13-valent pneumococcal conjugate vaccine]. Arch Pediatr 2012; 19:1132-9. [PMID: 22925540 DOI: 10.1016/j.arcped.2012.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 07/08/2012] [Accepted: 07/18/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Since 2001 in France, a nasopharyngeal carriage study was set up for children six to 24 months old. Any data are available for older children (25 to 60 months). The aim of this study is to compare the nasopharyngeal carriage in children with acute otitis media (AOM) or healthy between both age groups (6/24 months versus 25/60 months). Moreover, during the study period, the 13-valent pneumococcal conjugate vaccine (PCV13) has replaced PCV7 in June 2010. METHODS From October 2010 to June 2011, 58 pediatricians obtained nasopharyngeal swabs from children 6-60 months with acute otitis media (AOM) or healthy controls, to analyse the carriage of pneumococcus, Haemophilus influenzae, Moraxella catarrhalis, group A streptococcus and Staphylococcus aureus. RESULTS Of the 1557 enrolled children, 1258 were 6 to 24 months old (315 healthy and 943 AOM) and 299 were 25 to 60 months (102 healthy and 197 AOM). More then 85% were PCV7 vaccinated and the children of 25/60 months were rarely PCV13 vaccinated (14.1%) compared to younger children (69.9%, P<0.001). For children 6/24 months, the Streptococcus pneumoniae carriage was higher in AOM group (57.3%) versus healthy (28.9%). By contrast for older children, the difference (58.4% versus 50%) was not significant. In the healthy group, older children carried more often S. pneumoniae than younger children (50% versus 28.9%, P<0.0001). This trend was also observed for H. influenzae carriage (49% versus 18.7%, P<0.0001). Multivariate analysis in the healthy group showed that siblings and day care center (or school) increased the carriage of S. pneumoniae and H. influenzae. CONCLUSION These data from nasopharyngeal carriage in children 6 to 60 months old showed that pneumococcus and H. influenzae carriage is high for patients under 2 years, especially in the healthy group. Moreover, these data from the transition PCV7/PCV13, will serve as baseline in France to evaluate the impact of PCV13.
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Affiliation(s)
- R Cohen
- Association clinique et thérapeutique infantile du Val-de-Marne (ACTIV), 27, rue Inkermann, 94100 Saint-Maur-des-Fossés, France.
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Demczuk WH, Martin I, Griffith A, Lefebvre B, McGeer A, Shane A, Zhanel GG, Tyrrell GJ, Gilmour MW, Toronto Invasive Bacterial Diseases, Canadian Public Health Laboratory N. Serotype distribution of invasive Streptococcus pneumoniae in Canada during the introduction of the 13-valent pneumococcal conjugate vaccine, 2010. Can J Microbiol 2012; 58:1008-17. [DOI: 10.1139/w2012-073] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A baseline serotype distribution was established by age and region for 2058 invasive Streptococcus pneumoniae isolates collected during the implementation period of the 13-valent pneumococcal conjugate vaccine (PCV13) program in many parts of Canada in 2010. Serotypes 19A, 7F, and 3 were the most prevalent in all age groups, accounting for 57% in <2 year olds, 62% in 2–4 year olds, 45% in 5–14 year olds, 44% in 15–49 year olds, 41% in 50–64 year olds, and 36% in ≥65 year olds. Serotype 19A was most predominant in Western and Central Canada representing 15% and 22%, respectively, of the isolates from those regions, whereas 7F was most common in Eastern Canada with 20% of the isolates. Other prevalent serotypes include 15A, 23B, 12F, 22F, and 6C. PCV13 serotypes represented 65% of the pneumococci isolated from <2 year olds, 71% of 2–4 year olds, 61% of 5–14 year olds, 60% of 15–49 year olds, 53% of 50–64 year olds, and 49% of the ≥65 year olds. Continued monitoring of invasive pneumococcal serotypes in Canada is important to identify epidemiological trends and assess the impact of the newly introduced PCV13 vaccine on public health.
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Affiliation(s)
- Walter H.B. Demczuk
- National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, MB R3E 3R2, Canada
| | - Irene Martin
- National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, MB R3E 3R2, Canada
| | - Averil Griffith
- National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, MB R3E 3R2, Canada
| | - Brigitte Lefebvre
- Laboratoire de santé publique du Québec, 20045 chemin Sainte-Marie, Ste-Anne-de-Bellevue, QC H9X 3R5, Canada
| | - Allison McGeer
- Toronto Invasive Bacterial Diseases Network, Department of Microbiology, Mount Sinai Hospital, 600 University Avenue, Room 210, Toronto, ON M5G 1X5, Canada
| | - Amanda Shane
- Vaccine Preventable Diseases Section, Surveillance and Outbreak Response Division, Centre for Immunization and Respiratory Infectious Diseases, Public Health Agency of Canada, Room 273A, 2nd Floor, 130 Colonnade Road, AL 6502A, Ottawa, ON K1A 0K9, Canada
| | - George G. Zhanel
- Department of Medical Microbiology and Infectious Diseases, Faculty of Medicine, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Gregory J. Tyrrell
- Provincial Laboratory for Public Health (Microbiology), Walter Mackenzie Health Sciences Centre, 8440 - 112 Street, Edmonton, AB T6G 2J2, Canada
| | - Matthew W. Gilmour
- National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, MB R3E 3R2, Canada
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van Hoek AJ, Andrews N, Waight PA, Stowe J, Gates P, George R, Miller E. The effect of underlying clinical conditions on the risk of developing invasive pneumococcal disease in England. J Infect 2012; 65:17-24. [DOI: 10.1016/j.jinf.2012.02.017] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 02/08/2012] [Accepted: 02/28/2012] [Indexed: 10/28/2022]
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Serotype dynamics of invasive pneumococcal disease post-PCV7 and pre-PCV13 introduction in North East England. Epidemiol Infect 2012; 141:344-52. [PMID: 22564258 DOI: 10.1017/s0950268812000763] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The 7-valent pneumococcal conjugate vaccine (PCV7) has been included in the routine childhood immunization programme in the UK since September 2006. A population-based study of serotypes causing invasive pneumococcal disease (IPD) post-PCV7 in North East England was conducted using data from a regional enhanced IPD surveillance system. Overall, there was a 20% reduction [95% confidence interval (CI) 5-32] from 12·1 cases/100 000 population in 2006/2007 to 9·7 in 2009/2010. There was a fall in IPD caused by PCV7 serotypes in all age groups, with reductions of 90% (95% CI 61-99) in children aged <5 years, 50% (95% CI 4-75) in persons aged 5-64 years and 66% (95% CI 40-82) in adults aged ⩾65 years. There was a non-significant increase in IPD caused by non-PCV7 serotypes in children aged <5 years of 88% (95% CI -10 to 312) and adults aged ⩾65 years of 12% (95% CI -19 to 50), which was largely caused by serotypes 7F, 19A and 22F. Replacement disease appears to have reduced the benefits of PCV7 in North East England.
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Abstract
OBJECTIVES To examine invasive pneumococcal disease (IPD) incidence, the impact of the 7-valent pneumococcal conjugate vaccines (PCV7s) programme on the distribution of Streptococcus pneumoniae serotypes and risk factors for IPD among HIV-positive adults. METHODS We analysed adults (aged ≥15 years) reported to the HIV and IPD national datasets in England and Wales (2000-2009). Through data-linkage, changes in IPD incidence and serotype distribution were examined. Risk factors for IPD among HIV-positive adults were assessed using a case-control study. RESULTS Among 63,109 HIV-positive adults, 951 were co-infected with IPD. The average annual incidence of IPD was 245 episodes per 100,000 HIV-positive adults and 246 of 100,000 among those aged 15-44 years. Incidence was higher among those not on antiretroviral therapy (ART) (281 of 100,000) and those with severe immunosuppression (563 of 100,000). Among 9283 adults aged 15-44 at IPD diagnosis, 2.4% were living with undiagnosed HIV. The proportion of IPD episodes in HIV-positive adults with serotypes covered by PCV7 was 23% in 2009, a 54% proportional reduction compared with pre-PCV7 (2000-2006); the reduction in adults of unknown HIV status was 70%. The proportion of IPD episodes among HIV-positive adults caused by serotypes covered by PCV13 was 61%. Significant risk factors for IPD in multivariate analysis included older aged (≥65 years), a lower nadir CD4 cell count and no previous ART. CONCLUSION An HIV test should be offered and recommended to adults aged 15-44 years without other obvious IPD risk factors. Our study provides an evidence base to policy makers regarding the use of the new PCV13 in HIV-positive adults.
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Ritchie ND, Mitchell TJ, Evans TJ. What is different about serotype 1 pneumococci? Future Microbiol 2012; 7:33-46. [DOI: 10.2217/fmb.11.146] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Serotype 1 Streptococcus pneumoniae is among the most commonly isolated serotype in invasive pneumococcal disease but is rarely found causing asymptomatic nasopharyngeal colonization. Compared to infection by other serotypes, infection caused by serotype 1 is more likely to be identified in young patients without comorbidities but is generally associated with a lower mortality. Empyema and extrapulmonary manifestations are common. Outbreaks of serotype 1 disease have been reported in closed communities and epidemics are particularly common in sub-Saharan Africa. The serotype 1 capsular polysaccharide is a zwitterionic structure that enables it to function as a T-cell dependent antigen under some circumstances, in contrast to other pneumococcal capsular polysaccharides that are T-cell independent antigens. There are also differences in the key virulence factor pneumolysin in some serotype 1 isolates. The clinical significance of these differences remains to be determined.
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Affiliation(s)
- Neil D Ritchie
- Institute of Infection, Immunity & Inflammation, University of Glasgow, UK
| | - Tim J Mitchell
- Institute of Infection, Immunity & Inflammation, University of Glasgow, UK
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Abstract
Vaccination with heptavalent pneumococcal conjugate vaccine (PCV7) has significantly reduced the burden of pneumococcal disease and has had an important public health benefit. Because this vaccine targets only seven of the more than 92 pneumococcal serotypes, concerns have been raised that non-vaccine serotypes (NVTs) could increase in prevalence and reduce the benefits of vaccination. Indeed, among asymptomatic carriers, the prevalence of NVTs has increased substantially, and consequently, there has been little or no net change in the bacterial carriage prevalence. In many populations, pneumococcal disease caused by NVT has increased, but in most cases this increase has been less than the increase in NVT carriage. We review the evidence for serotype replacement in carriage and disease, and address the surveillance biases that might affect these findings. We then discuss possible reasons for the discrepancy between near-complete replacement in carriage and partial replacement for disease, including differences in invasiveness between vaccine serotypes. We contend that the magnitude of serotype replacement in disease can be attributed, in part, to a combination of lower invasiveness of the replacing serotypes, biases in the pre-vaccine carriage data (unmasking), and biases in the disease surveillance systems that could underestimate the true amount of replacement. We conclude by discussing the future potential for serotype replacement in disease and the need for continuing surveillance.
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Affiliation(s)
- Daniel M Weinberger
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA.
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Andrews N, Waight PA, Borrow R, Ladhani S, George RC, Slack MPE, Miller E. Using the indirect cohort design to estimate the effectiveness of the seven valent pneumococcal conjugate vaccine in England and Wales. PLoS One 2011; 6:e28435. [PMID: 22164292 PMCID: PMC3229580 DOI: 10.1371/journal.pone.0028435] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 11/08/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The 7-valent pneumococcal conjugate vaccine (PCV-7) was introduced in the United Kingdom in 2006 with a 2, 3 and 13 month schedule, and has led to large decreases in invasive pneumococcal disease (IPD) caused by the vaccine serotypes in both vaccinated and unvaccinated cohorts. We estimated the effectiveness of PCV-7 against IPD. METHODS AND FINDINGS We used enhanced surveillance data, collated at the Health Protection Agency, on vaccine type (n = 153) and non vaccine type (n = 919) IPD cases eligible for PCV-7. The indirect cohort method, a case-control type design which uses non vaccine type cases as controls, was used to estimate effectiveness of various numbers of doses as well as for each vaccine serotype. Possible bias with this design, caused by differential serotype replacement in vaccinated and unvaccinated individuals, was estimated after deriving formulae to quantify the bias. The results showed good effectiveness, increasing from 56% (95% confidence interval (CI): -7-82) for a single dose given under one year of age to 93% (95% CI: 70-98) for two doses under one year of age plus a booster dose in the second year of life. Serotype specific estimates indicated higher effectiveness against serotypes 4, 14 and 18C and lower effectiveness against 6B. Under the assumption of complete serotype replacement by non vaccine serotypes in carriage, we estimated that effectiveness estimates may be overestimated by about 2 to 5%. CONCLUSIONS This study shows high effectiveness of PCV-7 under the reduced schedule used in the UK. This finding agrees with the large reductions seen in vaccine type IPD in recent years in England and Wales. The formulae derived to assess the bias of the indirect cohort method for PCV-7 can also be used when using the design for other vaccines that affect carriage such as the recently introduced 13 valent pneumococcal conjugate vaccine.
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Affiliation(s)
- Nick Andrews
- Statistics, Modelling and Economics Department, Health Protection Services, Health Protection Agency, London, United Kingdom.
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Increasing incidence of invasive pneumococcal disease and pneumonia despite improved vaccination uptake: surveillance in Hull and East Yorkshire, UK, 2002-2009. Epidemiol Infect 2011; 140:1252-66. [PMID: 22040368 DOI: 10.1017/s0950268811001907] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Introduction of pneumococcal polysaccharide (PPV23) and conjugate vaccine (PCV7) programmes were expected to change the epidemiology of invasive pneumococcal disease (IPD) and pneumonia in the UK. We describe the epidemiology of IPD and hospitalization with pneumonia using high-quality surveillance data over an 8-year period, 2002-2009. Although PPV23 uptake increased from 49% to 70% and PCV7 uptake reached 98% by 2009, the overall incidence of IPD increased from 11.8/100 000 to 16.4/100 000 (P=0.13), and the incidence of hospitalization with pneumonia increased from 143/100 000 to 207/100 000 (P<0.001). Although a reduction in the proportion of IPD caused by PCV7 serotypes was observed, concurrent increases in PPV23 and non-vaccine serotype IPD contributed to an increased IPD burden overall. Marked inequalities in the geographical distribution of disease were observed. Existing vaccination programmes have, so far, not been sufficient to address an increasing burden of pneumococcal disease in our locality.
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Choi YH, Jit M, Gay N, Andrews N, Waight PA, Melegaro A, George R, Miller E. 7-Valent pneumococcal conjugate vaccination in England and Wales: is it still beneficial despite high levels of serotype replacement? PLoS One 2011; 6:e26190. [PMID: 22022559 PMCID: PMC3193519 DOI: 10.1371/journal.pone.0026190] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 09/22/2011] [Indexed: 11/20/2022] Open
Abstract
Background The UK introduced the 7-valent pneumococcal conjugate vaccine (PCV7) into the national vaccination program in September 2006. Previous modelling assumed that the likely impact of PCV7 on invasive pneumococcal disease (IPD) would be similar to the US experience with PCV7. However, recent surveillance data show a more rapid replacement of PCV7 IPD cases by non-PCV7 IPD cases than was seen in the US. Methods and Findings A previous model of pneumococcal vaccination was re-parameterised using data on vaccine coverage and IPD from England and Wales between 2006 and 2009. Disease incidence was adjusted for the increasing trend in reported IPD cases prior to vaccination. Using this data we estimated that individuals carrying PCV7 serotypes have much higher protection (96%;95% CI 72%-100%) against acquisition of NVT carriage than the 15% previously estimated from US data, which leads to greater replacement. However, even with this level of replacement, the annual number of IPD cases may be 560 (95% CI, -100 to 1230) lower ten years after vaccine introduction compared to what it may have been without vaccination. A particularly marked fall of 39% in children under 15 years by 2015/6 is predicted. Conclusion Our model suggests that PCV7 vaccination could result in a decrease in overall invasive pneumococcal disease, particularly in children, even in an environment of rapid replacement with non-PCV7 serotypes within 5 years of vaccine introduction at high coverage.
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Affiliation(s)
- Yoon Hong Choi
- Immunisation, Hepatitis and Blood Safety Department, Health Protection Agency, London, United Kingdom.
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Cohen JM, Khandavilli S, Camberlein E, Hyams C, Baxendale HE, Brown JS. Protective contributions against invasive Streptococcus pneumoniae pneumonia of antibody and Th17-cell responses to nasopharyngeal colonisation. PLoS One 2011; 6:e25558. [PMID: 22003400 PMCID: PMC3189185 DOI: 10.1371/journal.pone.0025558] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 09/07/2011] [Indexed: 11/18/2022] Open
Abstract
The nasopharyngeal commensal bacteria Streptococcus pneumoniae is also a frequent cause of serious infections. Nasopharyngeal colonisation with S. pneumoniae inhibits subsequent re-colonisation by inducing Th17-cell adaptive responses, whereas vaccination prevents invasive infections by inducing antibodies to S. pneumoniae capsular polysaccharides. In contrast, protection against invasive infection after nasopharyngeal colonisation with mutant S. pneumoniae strains was associated with antibody responses to protein antigens. The role of colonisation-induced Th17-cell responses during subsequent invasive infections is unknown. Using mouse models, we show that previous colonisation with S. pneumoniae protects against subsequent lethal pneumonia mainly by preventing bacteraemia with a more modest effect on local control of infection within the lung. Previous colonisation resulted in CD4-dependent increased levels of Th17-cell cytokines during subsequent infectious challenge. However, mice depleted of CD4 cells prior to challenge remained protected against bacteraemia, whereas no protection was seen in antibody deficient mice and similar protection could be achieved through passive transfer of serum. Serum from colonised mice but not antibody deficient mice promoted phagocytosis of S. pneumoniae, and previously colonised mice were able to rapidly clear S. pneumoniae from the blood after intravenous inoculation. Thus, despite priming for a Th17-cell response during subsequent infection, the protective effects of prior colonisation in this model was not dependent on CD4 cells but on rapid clearance of bacteria from the blood by antibody-mediated phagocytosis. These data suggest that whilst nasopharyngeal colonisation induces a range of immune responses, the effective protective responses depend upon the site of subsequent infection.
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Affiliation(s)
- Jonathan M. Cohen
- Centre for Respiratory Research, Department of Medicine, University College London, London, United Kingdom
- Infectious Diseases and Microbiology Unit, Child Health Institute, University College London, London, United Kingdom
| | - Suneeta Khandavilli
- Centre for Respiratory Research, Department of Medicine, University College London, London, United Kingdom
| | - Emilie Camberlein
- Centre for Respiratory Research, Department of Medicine, University College London, London, United Kingdom
| | - Catherine Hyams
- Centre for Respiratory Research, Department of Medicine, University College London, London, United Kingdom
| | - Helen E. Baxendale
- Infectious Diseases and Microbiology Unit, Child Health Institute, University College London, London, United Kingdom
- Department of Immunology, Royal Free Hospital Medical School Campus, University College London, London, United Kingdom
| | - Jeremy S. Brown
- Centre for Respiratory Research, Department of Medicine, University College London, London, United Kingdom
- * E-mail:
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