1
|
Tinggaard M, Slotved HC, Jørgensen CS, Kronborg G, Benfield T. Predictors of serological non-response to the 13-valent pneumococcal conjugate vaccine followed by the 23-valent polysaccharide vaccine among adults living with HIV. Vaccine 2023; 41:4414-4421. [PMID: 37316406 DOI: 10.1016/j.vaccine.2023.06.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/16/2023] [Accepted: 06/04/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND People living with HIV (PLWH) have higher incidence of pneumococcal disease compared to people without HIV. Immunization with pneumococcal vaccines is recommended, but serological non-response to pneumococcal vaccination is common for largely unknown reasons. METHODS PLWH on antiretroviral treatment and no prior pneumococcal vaccination received the 13-valent pneumococcal conjugate vaccine (PCV13) followed 60 days later by the 23-valent polysaccharide vaccine (PPV23). Serological response was evaluated 30 days post-PPV23 by antibodies against 12 serotypes covered by both PCV13 and PPV23. Seroprotection was defined as a ≥2-fold rise to a level above 1.3 µg/ml in geometric mean concentration (GMC) across all serotypes. Associations with non-responsiveness were evaluated by logistic regression. RESULTS Fifty-two virologically suppressed PLWH (median age of 50 years (IQR 44-55) and median CD4 count of 634 cells/mm3 (IQR 507-792)) were included. Forty-six percent (95 % CI 32-61, n = 24) achieved seroprotection. Serotypes 14, 18C and 19F had the highest, and serotypes 3, 4 and 6B the lowest GMCs. Pre-vaccination GMC levels less than 100 ng/ml were associated with increased odds of non-responsiveness compared to levels above 100 ng/ml (adjusted OR 8.7, 95 % CI 1.2-63.6, p = 0.0438). CONCLUSION Less than half of our study population achieved anti-pneumococcal seroprotective levels following PCV13 and PPV23 immunization. Low pre-vaccination GMC levels were associated with non-response. Further research is required to optimize vaccination strategies that achieve higher seroprotection in this high-risk group.
Collapse
Affiliation(s)
- Michaela Tinggaard
- Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, Hvidovre, Denmark.
| | - Hans-Christian Slotved
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | | | - Gitte Kronborg
- Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, Hvidovre, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Benfield
- Department of Infectious Diseases, Copenhagen University Hospital - Amager and Hvidovre, Hvidovre, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
2
|
See KC. Pneumococcal Vaccination in Adults: A Narrative Review of Considerations for Individualized Decision-Making. Vaccines (Basel) 2023; 11:vaccines11050908. [PMID: 37243012 DOI: 10.3390/vaccines11050908] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/22/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023] Open
Abstract
Pneumococcal disease remains one of the major causes of severe disease in both children and adults. Severe disease may be prevented by pneumococcal polysaccharide and conjugate vaccines, which currently cover more than 20 serotypes. However, unlike routine pneumococcal vaccination in children, guidelines promote only limited pneumococcal vaccination in adults, and do not cater for decision-making for individual patients. In this narrative review, considerations for individualized decision-making are identified and discussed. This review identifies and discusses considerations for individualized decision-making, including the risk of severe disease, immunogenicity, clinical efficacy, mucosal immunity, herd immunity, concomitant administration with other vaccines, waning immunity, and replacement strains.
Collapse
Affiliation(s)
- Kay Choong See
- Department of Medicine, National University Hospital, Singapore 119228, Singapore
| |
Collapse
|
3
|
Kim H, Yu J, Bai D, Nahm MH, Wang P. Potentiating pneumococcal glycoconjugate vaccine PCV13 with saponin adjuvant VSA-1. Front Immunol 2022; 13:1079047. [PMID: 36578488 PMCID: PMC9790987 DOI: 10.3389/fimmu.2022.1079047] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 11/21/2022] [Indexed: 12/14/2022] Open
Abstract
VSA-1 is a semisynthetic saponin adjuvant prepared from naturally occurring Momordica saponin and capable of stimulating antigen-specific humoral and cellular immune responses. Its immunostimulating activity in enhancing the immune responses induced by the clinical glycoconjugate pneumococcal vaccine PCV13 is compared with QS-21 in female BALB/c mice. Both VSA-1 and QS-21 boosted IgG and opsonic antibodies titers against seven selected serotypes, including serotypes 3, 14, and 19A that are involved in most PCV13 breakthroughs. Since VSA-1 is much more accessible and of lower toxicity than QS-21, it can be a practical saponin immunostimulant to be included in a new glycoconjugate pneumococcal vaccine formulation.
Collapse
Affiliation(s)
- Hyunjung Kim
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jigui Yu
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Di Bai
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Moon H. Nahm
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States,World Health Organization (WHO) Pneumococcal Serology Reference Laboratory, University of Alabama at Birmingham, Birmingham, AL, United States,*Correspondence: Moon H. Nahm, ; Pengfei Wang,
| | - Pengfei Wang
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, United States,*Correspondence: Moon H. Nahm, ; Pengfei Wang,
| |
Collapse
|
4
|
Durability of Antibody Response after Primary Pneumococcal Double-Dose Prime-Boost Vaccination in Adult Kidney Transplant Recipients and Candidates: 18-Month Follow-Up in a Non-Blinded, Randomised Clinical Trial. Vaccines (Basel) 2022; 10:vaccines10071091. [PMID: 35891255 PMCID: PMC9323946 DOI: 10.3390/vaccines10071091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 06/26/2022] [Accepted: 07/03/2022] [Indexed: 12/04/2022] Open
Abstract
Background: Pneumococcal prime-boost vaccination is recommended for solid organ transplant recipients and candidates. The long-term durability of the antibody (AB) response is unknown. The same applies to a dose-dependent immune response. Methods: We studied the durability of the vaccine response after 18 months in kidney transplant recipients (KTRs) and patients on the kidney transplant waiting list (WLPs). Both groups received either a normal dose (ND) or a double dose (DD) of the 13-valent pneumococcal conjugate vaccine and the 23-valent pneumococcal polysaccharide vaccine. The average pneumococcal AB geometric mean concentration (GMC) was evaluated. A level ≥ 1 mg/L was considered protective against invasive pneumococcal disease (IPD). Results: Sixty WLPs and 70 KTRs were included. The proportion of participants protected declined from 52% to 33% in WLPs and from 29% to 16% in KTRs, with the previously significant dose-effect in WLPs no longer present (40% DD vs. 27% ND; p = 0.273). Average pneumococcal AB GMCs remained significantly above baseline levels (all groups p ≤ 0.001). Drug-induced immunosuppression diminished the vaccine dose-effect. Conclusions: At follow-up, the pneumococcal prime-boost vaccination still provided significantly elevated average pneumococcal AB GMCs in both populations. Though the proportion of participants protected against IPD in WLP-DD and WLP-ND were statistically comparable, a DD may still be recommended for WLPs (EudraCT: 2016-004123-23).
Collapse
|
5
|
Immunogenicity and safety of double dosage of pneumococcal vaccines in adult kidney transplant recipients and waiting list patients: A non-blinded, randomized clinical trial. Vaccine 2022; 40:3884-3892. [PMID: 35644672 DOI: 10.1016/j.vaccine.2022.05.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/09/2022] [Accepted: 05/15/2022] [Indexed: 01/07/2023]
Abstract
BACKGROUND Pneumococcal prime-boost vaccination is recommended for solid organ transplant recipients, but is not thoroughly tested in this population. Furthermore, a pneumococcal vaccine dose effect has never been investigated, though observed in healthy adults. To assess whether a double dose of 13-valent pneumococcal conjugate vaccine (PCV13) and of 23-valent pneumococcal polysaccharide vaccine (PPV23) increases the immunogenicity of prime-boost vaccination in kidney transplant recipients (KTRs) and patients on the kidney transplant waiting list (WLPs), a phase 3, randomized, non-blinded trial was conducted. METHODS KTRs and WLPs were in parallel groups assigned either normal or double dosage of both vaccines 12 weeks apart. A 'protective response' was an average geometric mean concentration ≥ 1 mg/L based on 12 vaccine shared serotype-specific IgG antibodies. Furthermore, number of antibodies with ≥ 2-fold rises and individual serotype-specific antibody concentrations were evaluated. Follow-up was 48 weeks. RESULTS Seventy-four KTRs and 65 WLPs were enrolled. In WLPs, double dosage resulted in a significantly higher proportion of participants with a 'protective response' (66.7%), 5 weeks after PPV23, compared to normal dosage (35.5%), p = 0.015. KTRs exhibited no dose effect. After PPV23, all four groups had increased their number of serotypes with ≥ 2-fold rises (p ≤ 0.05 for both WLPs groups; p ≤ 0.01 for both KTRs groups). Vaccines were safe, well tolerated and still immunogenic at week 48. CONCLUSIONS Data suggests that double dosage of pneumococcal vaccines used according to the prime-boost strategy might be recommendable for WLPs. Furthermore, our data supports PPV23́s additive effect to PCV13 in KTRs and WLPs. (EudraCT: 2016-004123-23).
Collapse
|
6
|
LaFon D, Kim YI, Burton R, Dransfield M, Nahm M. Pneumococcal Antibody Function for Immunologic Evaluation: Normal Results in Older Adults, and a Novel Analytical Model for Vaccine Response. J Clin Immunol 2021; 41:1964-1968. [PMID: 34462839 DOI: 10.1007/s10875-021-01126-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Affiliation(s)
- David LaFon
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama At Birmingham, Birmingham, AL, USA. .,UAB Lung Health Center, University of Alabama At Birmingham, Birmingham, AL, USA.
| | - Young-Il Kim
- Division of Preventive Medicine, University of Alabama At Birmingham, Birmingham, AL, USA
| | - Robert Burton
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama At Birmingham, Birmingham, AL, USA
| | - Mark Dransfield
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama At Birmingham, Birmingham, AL, USA.,UAB Lung Health Center, University of Alabama At Birmingham, Birmingham, AL, USA.,Birmingham VA Medical Center, Birmingham, AL, USA
| | - Moon Nahm
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama At Birmingham, Birmingham, AL, USA.,Department of Microbiology, University of Alabama At Birmingham, Birmingham, AL, USA
| |
Collapse
|
7
|
Abstract
The proportion of the global population aged 65 and older is rapidly increasing. Infections in this age group, most recently with SARS-CoV-2, cause substantial morbidity and mortality. Major improvements have been made in vaccines for older people, either through the addition of novel adjuvants-as in the new recombinant zoster vaccine and an adjuvanted influenza vaccine-or by increasing antigen concentration, as in influenza vaccines. In this article we review improvements in immunization for the three most important vaccine preventable diseases of aging. The recombinant zoster vaccine has an efficacy of 90% that is minimally affected by the age of the person being vaccinated and persists for more than four years. Increasing antigen dose or inclusion of adjuvant has improved the immunogenicity of influenza vaccines in older adults, although the relative effectiveness of the enhanced influenza vaccines and the durability of the immune response are the focus of ongoing clinical trials. Conjugate and polysaccharide pneumococcal vaccines have similar efficacy against invasive pneumococcal disease and pneumococcal pneumonia caused by vaccine serotypes in older adults. Their relative value varies by setting, depending on the prevalence of vaccine serotypes, largely related to conjugate vaccine coverage in children. Improved efficacy will increase public confidence and uptake of these vaccines. Co-administration of these vaccines is feasible and important for maximal uptake in older people. Development of new vaccine platforms has accelerated following the arrival of SARS-CoV-2, and will likely result in new vaccines against other pathogens in the future.
Collapse
Affiliation(s)
- Anthony L Cunningham
- Centre for Virus Research, The Westmead Institute for Medical Research, Faculty of Medicine and Health, University of Sydney, Australia
| | - Peter McIntyre
- Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Kanta Subbarao
- WHO CollaboratingCentre for Reference and Research on Influenza and Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Robert Booy
- National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The Children's Hospital at Westmead, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, School of Biological Sciences and Sydney Medical School, University of Sydney, Australia
| | - Myron J Levin
- Departments of Pediatrics and Medicine, University of Colorado School of Medicine Anschutz Medical Campus, Aurora, Colorado, USA
| |
Collapse
|
8
|
Therapeutic Activity of Type 3 Streptococcus pneumoniae Capsule Degrading Enzyme Pn3Pase. Pharm Res 2020; 37:236. [PMID: 33140159 PMCID: PMC7605875 DOI: 10.1007/s11095-020-02960-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 10/19/2020] [Indexed: 02/08/2023]
Abstract
Purpose Streptococcus pneumoniae (Spn) serotype 3 (Spn3) is considered one of the most virulent serotypes with resistance to conventional vaccine and treatment regimens. Pn3Pase is a glycoside hydrolase that we have previously shown to be highly effective in degrading the capsular polysaccharide of type 3 Spn, sensitizing it to host immune clearance. To begin assessing the value and safety of this enzyme for future clinical studies, we investigated the effects of high doses of Pn3Pase on host cells and immune system. Methods We assessed the enzyme’s catalytic activity following administration in mice, and performed septic infection models to determine if prior administration of the enzyme inhibited repeat treatments of Spn3-challenged mice. We assessed immune populations in mouse tissues following administration of the enzyme, and tested Pn3Pase toxicity on other mammalian cell types in vitro. Results Repeated administration of the enzyme in vivo does not prevent efficacy of the enzyme in promoting bacterial clearance following bacterial challenge, with insignificant antibody response generated against the enzyme. Immune homeostasis is maintained following high-dose treatment with Pn3Pase, and no cytotoxic effects were observed against mammalian cells. Conclusions These data indicate that Pn3Pase has potential as a therapy against Spn3. Further development as a drug product could overcome a great hurdle of pneumococcal infections.
Collapse
|
9
|
Rouphael NG, Morgan C, Li SS, Jensen R, Sanchez B, Karuna S, Swann E, Sobieszczyk ME, Frank I, Wilson GJ, Tieu HV, Maenza J, Norwood A, Kobie J, Sinangil F, Pantaleo G, Ding S, McElrath MJ, De Rosa SC, Montefiori DC, Ferrari G, Tomaras GD, Keefer MC. DNA priming and gp120 boosting induces HIV-specific antibodies in a randomized clinical trial. J Clin Invest 2020; 129:4769-4785. [PMID: 31566579 PMCID: PMC6819112 DOI: 10.1172/jci128699] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 07/24/2019] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND RV144 is the only preventive HIV vaccine regimen demonstrating efficacy in humans. Attempting to build upon RV144 immune responses, we conducted a phase 1, multicenter, randomized, double-blind trial to assess the safety and immunogenicity of regimens substituting the DNA-HIV-PT123 (DNA) vaccine for ALVAC-HIV in different sequences or combinations with AIDSVAX B/E (protein). METHODS One hundred and four HIV-uninfected participants were randomized to 4 treatment groups (T1, T2, T3, and T4) and received intramuscular injections at 0, 1, 3, and 6 months (M): T1 received protein at M0 and M1 and DNA at M3 and M6; T2 received DNA at M0 and M1 and protein at M3 and M6; T3 received DNA at M0, M1, M3, and M6 with protein coadministered at M3 and M6; and T4 received protein and DNA coadministered at each vaccination visit. RESULTS All regimens were well tolerated. Antibodies binding to gp120 and V1V2 scaffold were observed in 95%–100% of participants in T3 and T4, two weeks after final vaccination at high magnitude. While IgG3 responses were highest in T3, a lower IgA/IgG ratio was observed in T4. Binding antibodies persisted at 12 months in 35%–100% of participants. Antibody-dependent cell-mediated cytotoxicity and tier 1 neutralizing-antibody responses had higher response rates for T3 and T4, respectively. CD4+ T cell responses were detectable in all treatment groups (32%–64%) without appreciable CD8+ T cell responses. CONCLUSION The DNA/protein combination regimens induced high-magnitude and long-lasting HIV V1V2–binding antibody responses, and early coadministration of the 2 vaccines led to a more rapid induction of these potentially protective responses. TRIAL REGISTRATION ClinicalTrials.gov NCT02207920. FUNDING National Institute of Allergy and Infectious Diseases (NIAID) grants UM1 AI068614, UM1 AI068635, UM1 AI068618, UM1 AI069511, UM1 AI069470, UM1 AI069534, P30 AI450008, UM1 AI069439, UM1 AI069481, and UM1 AI069496; the National Center for Advancing Translational Sciences, NIH (grant UL1TR001873); and the Bill & Melinda Gates Foundation (grant OPP52845).
Collapse
Affiliation(s)
- Nadine G Rouphael
- Hope Clinic of the Emory Vaccine Center, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
| | - Cecilia Morgan
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Shuying S Li
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Ryan Jensen
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Brittany Sanchez
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Shelly Karuna
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Edith Swann
- Division of AIDS, NIH, Bethesda, Maryland, USA
| | | | - Ian Frank
- University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | - Janine Maenza
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.,University of Washington, Seattle, Washington, USA
| | | | - James Kobie
- Department of Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York, USA
| | - Faruk Sinangil
- Global Solutions for Infectious Diseases, South San Francisco, California, USA
| | - Giuseppe Pantaleo
- Division of Immunology and Allergy, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Song Ding
- EuroVacc Foundation, Lausanne, Switzerland
| | - M Juliana McElrath
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Stephen C De Rosa
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - David C Montefiori
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Guido Ferrari
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Georgia D Tomaras
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Michael C Keefer
- Department of Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York, USA
| | | |
Collapse
|
10
|
Matanock A, Lee G, Gierke R, Kobayashi M, Leidner A, Pilishvili T. Use of 13-Valent Pneumococcal Conjugate Vaccine and 23-Valent Pneumococcal Polysaccharide Vaccine Among Adults Aged ≥65 Years: Updated Recommendations of the Advisory Committee on Immunization Practices. MMWR-MORBIDITY AND MORTALITY WEEKLY REPORT 2019; 68:1069-1075. [PMID: 31751323 PMCID: PMC6871896 DOI: 10.15585/mmwr.mm6846a5] [Citation(s) in RCA: 227] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
11
|
Paschall AV, Middleton DR, Avci FY. Opsonophagocytic Killing Assay to Assess Immunological Responses Against Bacterial Pathogens. J Vis Exp 2019. [PMID: 31009013 DOI: 10.3791/59400] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
A key aspect of the immune response to bacterial colonization of the host is phagocytosis. An opsonophagocytic killing assay (OPKA) is an experimental procedure in which phagocytic cells are co-cultured with bacterial units. The immune cells will phagocytose and kill the bacterial cultures in a complement-dependent manner. The efficiency of the immune-mediated cell killing is dependent on a number of factors and can be used to determine how different bacterial cultures compare with regard to resistance to cell death. In this way, the efficacy of potential immune-based therapeutics can be assessed against specific bacterial strains and/or serotypes. In this protocol, we describe a simplified OPKA that utilizes basic culture conditions and cell counting to determine bacterial cell viability after co-culture with treatment conditions and HL-60 immune cells. This method has been successfully utilized with a number of different pneumococcal serotypes, capsular and acapsular strains, and other bacterial species. The advantages of this OPKA protocol are its simplicity, versatility (as this assay is not limited to antibody treatments as opsonins), and minimization of time and reagents to assess basic experimental groups.
Collapse
Affiliation(s)
- Amy V Paschall
- Department of Biochemistry and Molecular Biology, Center for Molecular Medicine and Complex Carbohydrate Research Center, University of Georgia
| | - Dustin R Middleton
- Department of Biochemistry and Molecular Biology, Center for Molecular Medicine and Complex Carbohydrate Research Center, University of Georgia
| | - Fikri Y Avci
- Department of Biochemistry and Molecular Biology, Center for Molecular Medicine and Complex Carbohydrate Research Center, University of Georgia;
| |
Collapse
|
12
|
Yang J, Li J, Wang S, Luo L, Liu P. Comparison of three sample size calculation methods for non-inferiority vaccine trials with multiple continuous co-primary endpoints. Hum Vaccin Immunother 2018; 15:256-263. [PMID: 30273507 DOI: 10.1080/21645515.2018.1514221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Clinical trials that study immunogenicity of combination vaccines often have less power than desirable. To make up for the reduction in statistical power at the study level, researchers have to increase the study sample size. To study immunogenicity variables, we used the geometric mean concentration of immune response after vaccination as immunologic endpoint and compared 3 sample size calculation methods: the "Inflation factors" method, the "Incrementing" method, and the "Bonferroni correction" method when there are multiple continuous co-primary endpoints. The parameters were set according to the actual situation of the use of combination vaccines and the simulation results were used as reference. The present study demonstrates that all 3 methods are applicable when the effect size of each endpoint is similar and the endpoints are at most weakly correlated, but when there is a true difference in effect sizes among endpoints, the "Incrementing" method has the best performance.
Collapse
Affiliation(s)
- Jiaying Yang
- a Department of Epidemiology and Biostatistics , Southeast University , Nanjing , China
| | - Jingxin Li
- b Jiangsu Province Center for Disease Control and Prevention , Nanjing , China
| | - Shiyuan Wang
- a Department of Epidemiology and Biostatistics , Southeast University , Nanjing , China
| | - Li Luo
- a Department of Epidemiology and Biostatistics , Southeast University , Nanjing , China
| | - Pei Liu
- a Department of Epidemiology and Biostatistics , Southeast University , Nanjing , China
| |
Collapse
|
13
|
Enzymatic Hydrolysis of Pneumococcal Capsular Polysaccharide Renders the Bacterium Vulnerable to Host Defense. Infect Immun 2018; 86:IAI.00316-18. [PMID: 29866907 DOI: 10.1128/iai.00316-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 05/30/2018] [Indexed: 12/15/2022] Open
Abstract
Despite a century of investigation, Streptococcus pneumoniae remains a major human pathogen, causing a number of diseases, such as pneumonia, meningitis, and otitis media. Like many encapsulated pathogens, the capsular polysaccharide (CPS) of S. pneumoniae is a critical component for colonization and virulence in mammalian hosts. This study aimed to evaluate the protective role of a glycoside hydrolase, Pn3Pase, targeting the CPS of type 3 S. pneumoniae, which is one of the most virulent serotypes. We have assessed the ability of Pn3Pase to degrade the capsule on a live type 3 strain. Through in vitro assays, we observed that Pn3Pase treatment increases the bacterium's susceptibility to phagocytosis by macrophages and complement-mediated killing by neutrophils. We have demonstrated that in vivo Pn3Pase treatment reduces nasopharyngeal colonization and protects mice from sepsis caused by type 3 S. pneumoniae Due to the increasing shifts in serotype distribution, the rise in drug-resistant strains, and poor immune responses to vaccine-included serotypes, it is necessary to investigate approaches to combat pneumococcal infections. This study evaluates the interaction of pneumococcal CPS with the host at molecular, cellular, and systemic levels and offers an alternative therapeutic approach for diseases caused by S. pneumoniae through enzymatic hydrolysis of the CPS.
Collapse
|
14
|
Wantuch PL, Avci FY. Current status and future directions of invasive pneumococcal diseases and prophylactic approaches to control them. Hum Vaccin Immunother 2018; 14:2303-2309. [PMID: 29757699 PMCID: PMC6183136 DOI: 10.1080/21645515.2018.1470726] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Streptococcus pneumoniae is a major human bacterial pathogen responsible for millions of deaths each year and significantly more illnesses worldwide. With over 90 different serotypes, providing effective vaccine programs has been a continuing challenge. Since 1983, the world has been introduced to four different pneumococcal vaccines (PPSV23, PCV7, PCV10, and PCV13) each with their own complications and successes. Since vaccination programs began, a decrease in the overall rate of pneumococcal pneumonia and associated diseases has been observed, notably in higher risk populations. However, with a decrease in incidence of vaccine type pneumococcal serotypes, increases in non-vaccine serotypes of the bacteria have been observed along with serotype switching. Additionally, a rise in antibiotic resistant strains of S. pneumoniae is noted. Here we discuss both the positive and negative clinical manifestations of pneumonia vaccine programs and discuss the challenges in pneumococcal vaccine design.
Collapse
Affiliation(s)
- Paeton L Wantuch
- a Department of Biochemistry and Molecular Biology , Center for Molecular Medicine and Complex Carbohydrate Research Center, University of Georgia , Athens , GA , USA
| | - Fikri Y Avci
- a Department of Biochemistry and Molecular Biology , Center for Molecular Medicine and Complex Carbohydrate Research Center, University of Georgia , Athens , GA , USA
| |
Collapse
|