1
|
Swarthout TD, Henrion MYR, Thindwa D, Meiring JE, Mbewe M, Kalizang'Oma A, Brown C, Msefula J, Moyo B, Mataya AA, Barnaba S, Pearce E, Gordon M, Goldblatt D, French N, Heyderman RS. Waning of antibody levels induced by a 13-valent pneumococcal conjugate vaccine, using a 3 + 0 schedule, within the first year of life among children younger than 5 years in Blantyre, Malawi: an observational, population-level, serosurveillance study. THE LANCET. INFECTIOUS DISEASES 2022; 22:1737-1747. [PMID: 36029796 PMCID: PMC10555849 DOI: 10.1016/s1473-3099(22)00438-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/25/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Pneumococcal conjugate vaccines (PCVs) induce serotype-specific IgG antibodies, effectively reducing vaccine-serotype carriage and invasive pneumococcal disease (IPD). IgG production wanes approximately 1 month after vaccination in absence of serotype-specific exposure. With uncertainty surrrounding correlate of protection (CoP) estimates and with persistent vaccine-serotype carriage and vaccine-serotype IPD after PCV13 introduction, we aimed to profile population-level immunogenicity among children younger than 5 years in Blantyre, Malawi. METHODS For this serosurveillance study, we used a random subset of samples from a prospective population-based serosurvey in Blantyre, Malawi, done between Dec 16, 2016, and June 27, 2018. Sample selection was based on age category optimisation among children younger than 5 years, adequate sample volume, and available budget. We measured serotype-specific IgGs against the 13 vaccine serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) and two non-vaccine serotypes (12F and 33F), as well as IgGs against three pneumococcal proteins (PsaA, NanA, and Ply), using ELISA and a direct-binding electrochemiluminescence-based multiplex assay. We estimated population-level, serotype-specific immunogenicity profiles using a linear spline regression model. Analyses included samples stratified to 20 3-month age strata (eg, age <3 months to 57-59 months). FINDINGS We evaluated 638 plasma samples: 556 primary samples and 82 unique secondary samples (each linked to one primary sample). Immunogenicity profiles revealed a consistent pattern among vaccine serotypes except serotype 3: a vaccine-induced IgG peak followed by waning to a nadir and subsequent increase in titre. For serotype 3, we observed no apparent vaccine-induced increase. Heterogeneity in parameters included age range at post-vaccination nadir (from 11·2 months [19A] to 27·3 months [7F]). The age at peak IgG titre ranged from 2·69 months (5) to 6·64 months (14). Titres dropped below CoPs against IPD among nine vaccine serotypes (1, 3, 4, 5, 6B, 7F, 9V, 18C, and 23F) and below CoPs against carriage for ten vaccine serotypes (1, 4, 5, 6B, 7F, 9V, 14, 18C, 19F, and 23F). Increasing antibody concentrations among older children and seroincident events were consistent with ongoing vaccine-serotype exposure. INTERPRETATION A 3 + 0 PCV13 schedule with high uptake has not led to sustained population-level antibody immunity beyond the first year of life. Indeed, post-vaccine antibody concentrations dropped below putative CoPs for several vaccine serotypes, potentially contributing to persistent vaccine-serotype carriage and residual vaccine-serotype IPD in Malawi and other similar settings. Policy decisions should consider alternative vaccine strategies, including a booster dose, to achieve sustained vaccine-induced antibody titres, and thus control. FUNDING Bill & Melinda Gates Foundation, Wellcome UK, and National Institute for Health and Care Research.
Collapse
Affiliation(s)
- Todd D Swarthout
- National Institute for Health and Care Research Mucosal Pathogens Research Unit, Research Department of Infection, Division of Infection and Immunity, University College London, London, UK; Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi.
| | - Marc Y R Henrion
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi; Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Deus Thindwa
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi; Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - James E Meiring
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Maurice Mbewe
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
| | - Akuzike Kalizang'Oma
- National Institute for Health and Care Research Mucosal Pathogens Research Unit, Research Department of Infection, Division of Infection and Immunity, University College London, London, UK; Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
| | - Comfort Brown
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
| | - Jacquline Msefula
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi; Faculty of Medicine, University of Amsterdam, Amsterdam, Netherlands
| | - Brewster Moyo
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
| | - Andrew A Mataya
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
| | - Susanne Barnaba
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi; Chancellor College, University of Malawi, Blantyre, Malawi
| | - Emma Pearce
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Melita Gordon
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi; Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - David Goldblatt
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Neil French
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Robert S Heyderman
- National Institute for Health and Care Research Mucosal Pathogens Research Unit, Research Department of Infection, Division of Infection and Immunity, University College London, London, UK
| |
Collapse
|
2
|
Mackenzie GA, Osei I, Salaudeen R, Hossain I, Young B, Secka O, D'Alessandro U, Palmu AA, Jokinen J, Hinds J, Flasche S, Mulholland K, Nguyen C, Greenwood B. A cluster-randomised, non-inferiority trial of the impact of a two-dose compared to three-dose schedule of pneumococcal conjugate vaccination in rural Gambia: the PVS trial. Trials 2022; 23:71. [PMID: 35073989 PMCID: PMC8785014 DOI: 10.1186/s13063-021-05964-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/22/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Pneumococcal conjugate vaccines (PCV) effectively prevent pneumococcal disease but the global impact of pneumococcal vaccination is hampered by the cost of PCV. The relevance and feasibility of trials of reduced dose schedules is greatest in middle- and low-income countries, such as The Gambia, where PCV has been introduced with good disease control but where transmission of vaccine-type pneumococci persists. We are conducting a large cluster-randomised, non-inferiority, field trial of an alternative reduced dose schedule of PCV compared to the standard schedule, the PVS trial. METHODS PVS is a prospective, cluster-randomised, non-inferiority, real-world field trial of an alternative schedule of one dose of PCV scheduled at age 6 weeks with a booster dose at age 9 months (i.e. the alternative '1 + 1' schedule) compared to the standard schedule of three primary doses scheduled at 6, 10, and 14 weeks of age (i.e. the standard '3 + 0' schedule). The intervention will be delivered for 4 years. The primary endpoint is the population-level prevalence of nasopharyngeal vaccine-type pneumococcal carriage in children aged 2 weeks to 59 months with clinical pneumonia in year 4 of the trial. Participants and field staff are not masked to group allocation while measurement of the laboratory endpoint will be masked. Sixty-eight geographic population clusters have been randomly allocated, in a 1:1 ratio, to each schedule and all resident infants are eligible for enrolment. All resident children less than 5 years of age are under continuous surveillance for clinical safety endpoints measured at 11 health facilities; invasive pneumococcal disease, radiological pneumonia, clinical pneumonia, and hospitalisations. Secondary endpoints include the population-level prevalence of nasopharyngeal vaccine-type pneumococcal carriage in years 2 and 4 and vaccine-type carriage prevalence in unimmunised infants aged 6-12 weeks in year 4. The trial includes components of mathematical modelling, health economics, and health systems research. DISCUSSION Analysis will account for potential non-independence of measurements by cluster, comparing the population-level impact of the two schedules with interpretation at the individual level. The non-inferiority margin is informed by the 'acceptable loss of effect' of the alternative compared to the standard schedule. The secondary endpoints will provide substantial evidence to support the interpretation of the primary endpoint. PVS will evaluate the effect of transition from a standard 3+ 0 schedule to an alternative 1 + 1 schedule in a setting of high pneumococcal transmission. The results of PVS will inform global decision-making concerning the use of reduced-dose PCV schedules. TRIAL REGISTRATION International Standard Randomised Controlled Trial Number 15056916 . Registered on 15 November 2018.
Collapse
Affiliation(s)
- Grant A Mackenzie
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, Gambia.
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
- Murdoch Children's Research Institute, Melbourne, Australia.
- Department of Paediatrics, University of Melbourne, Melbourne, Australia.
| | - Isaac Osei
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, Gambia
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Rasheed Salaudeen
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, Gambia
| | - Ilias Hossain
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, Gambia
| | - Benjamin Young
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, Gambia
| | - Ousman Secka
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, Gambia
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, Gambia
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Arto A Palmu
- Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Jukka Jokinen
- Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Jason Hinds
- Institute for Infection and Immunity St George's University of London, London, UK
- BUGS Bioscience, London Bioscience Innovation Centre, London, UK
| | - Stefan Flasche
- Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Kim Mulholland
- Murdoch Children's Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Cattram Nguyen
- Murdoch Children's Research Institute, Melbourne, Australia
| | - Brian Greenwood
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| |
Collapse
|
3
|
Mackenzie GA, Osei I, Salaudeen R, Secka O, D'Alessandro U, Clarke E, Schmidt-Chanasit J, Licciardi PV, Nguyen C, Greenwood B, Mulholland K. Pneumococcal conjugate vaccination schedules in infants-acquisition, immunogenicity, and pneumococcal conjugate and yellow fever vaccine co-administration study. Trials 2022; 23:39. [PMID: 35033180 PMCID: PMC8760872 DOI: 10.1186/s13063-021-05949-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 12/17/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Pneumococcal conjugate vaccines (PCVs) effectively prevent pneumococcal disease, but the global impact of pneumococcal vaccination is hampered by its cost. The evaluation of reduced dose schedules of PCV includes measurement of effects on immunogenicity and carriage acquisition compared to standard schedules. The relevance and feasibility of trials of reduced dose schedules is greatest in middle- and low-income countries, such as The Gambia, where the introduction of PCV resulted in good disease control but where transmission of vaccine-type pneumococci persists. We designed a large cluster-randomised field trial of an alternative reduced dose schedule of PCV compared to the standard schedule, the PVS trial. We will also conduct a sub-study to evaluate the individual-level effect of the two schedules on carriage acquisition, immunogenicity, and co-administration of PCV with yellow fever vaccine, the PVS-AcqImm trial. METHODS PVS-AcqImm is a prospective, cluster-randomised trial of one dose of PCV scheduled at age 6 weeks with a booster dose at age 9 months (i.e. alternative '1+1' schedule) compared to three primary doses scheduled at 6, 10, and 14 weeks of age (i.e. standard '3+0' schedule). Sub-groups within the alternative schedule group will receive yellow fever vaccine separately or co-administered with PCV at 9 months of age. The primary endpoints are (a) rate of nasopharyngeal vaccine-type pneumococcal acquisition from 9 to 14 months of age, (b) geometric mean concentration of vaccine-type pneumococcal IgG at 18 months of age, and (c) proportions with yellow fever neutralising antibody titre ≥8 four weeks after administration of yellow fever vaccine. Participants and field staff will not be masked to group allocation while the measurement of laboratory endpoints will be masked. Approximately equal numbers of participants will be resident in each of 28 geographic clusters (14 clusters in alternative and standard schedule groups); 784 enrolled for acquisition measurements and 336 for immunogenicity measurements. DISCUSSION Analysis will account for potential non-independence of measurements by cluster and so interpretation of effects will be at the individual level (i.e. a population of individuals). PVS-AcqImm will evaluate whether acquisition of vaccine-type pneumococci is reduced by the alternative compared to the standard schedule, which is required if the alternative schedule is to be effective. Likewise, evidence of superior immune response at 18 months of age and safety of PCV co-administration with yellow fever vaccine will support decision-making regarding the use of the alternative 1+1 schedule. Acquisition and immunogenicity outcomes will be essential for the interpretation of the results of the large field trial comparing the two schedules. TRIAL REGISTRATION International Standard Randomised Controlled Trial Number 72821613 .
Collapse
Affiliation(s)
- Grant A Mackenzie
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia.
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
- Murdoch Children's Research Institute, Melbourne, Australia.
- Department of Paediatrics, University of Melbourne, Melbourne, Australia.
| | - Isaac Osei
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Rasheed Salaudeen
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia
| | - Ousman Secka
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia
| | - Ed Clarke
- Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia
| | | | | | - Cattram Nguyen
- Murdoch Children's Research Institute, Melbourne, Australia
| | - Brian Greenwood
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Kim Mulholland
- Murdoch Children's Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, UK
| |
Collapse
|
4
|
Kaur R, Pichichero M. Comparison of anti-capsular antibody quantity and functionality in children after different primary dose and booster schedules of 13 valent-pneumococcal conjugate vaccine. Vaccine 2020; 38:4423-4431. [PMID: 32402752 DOI: 10.1016/j.vaccine.2020.04.063] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 04/06/2020] [Accepted: 04/26/2020] [Indexed: 11/30/2022]
Abstract
Different schedules for pediatric use of the 13-valent pneumococcal conjugate vaccine (PCV-13) are recommended in different countries and the U.S. Advisory Committee on Immunization Practices (ACIP) has considered potential of changing from 3 primary doses plus a booster (3p + 1) to two primary doses plus a booster (2p + 1) for protection against Streptococcus pneumoniae. In this paper, we report results of IgG antibody measured by ELISA and opsonophagocytic assay (OPA) after 2p, 3p, at child age 15 months of pre-booster and 18 months (post-booster) in serum samples opportunistically available from a prior study that focused on PCV effectiveness against AOM. A total of ~ 100 sera for each of the 4 study time points (390 sera tested) from 169 children were tested. Geometric mean concentrations (GMCs) and percentage of children exceeding the presumed protective antibody thresholds measured by ELISA and OPA were calculated. 2p doses produced lower antibody levels measured by ELISA but not OPA until the booster dose for serotypes 6A, 6B, 5 and 23F only. Booster dosing at 15 months resulted in significant increases in antibody. There was no difference in the percentage of children with ≥ correlate of protection (COP) for OPA for 2p vs 3p doses except for serotype 23F. A 2p + 0 or 3p + 0 schedule would likely result in many children failing to sustain protective levels of antibody into the second year of life. We conclude that protection from invasive pneumococcal infection in early childhood would be similar for most serotypes in PCV13 using a 2p + 1 or 3p + 1 but not a 2p + 0 or 3p + 0 schedule.
Collapse
Affiliation(s)
- Ravinder Kaur
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester, NY, United States.
| | - Michael Pichichero
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester, NY, United States
| |
Collapse
|
5
|
Adebanjo TA, Pondo T, Yankey D, Hill HA, Gierke R, Apostol M, Barnes M, Petit S, Farley M, Harrison LH, Holtzman C, Baumbach J, Bennett N, McGuire S, Thomas A, Schaffner W, Beall B, Whitney CG, Pilishvili T. Pneumococcal Conjugate Vaccine Breakthrough Infections: 2001-2016. Pediatrics 2020; 145:peds.2019-0836. [PMID: 32054822 PMCID: PMC7055927 DOI: 10.1542/peds.2019-0836] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/14/2019] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Most countries use 3-dose pneumococcal conjugate vaccine (PCV) schedules; a 4-dose (3 primary and 1 booster) schedule is licensed for US infants. We evaluated the invasive pneumococcal disease (IPD) breakthrough infection incidence in children receiving 2 vs 3 primary PCV doses with and without booster doses (2 + 1 vs 3 + 1; 2 + 0 vs 3 + 0). METHODS We used 2001-2016 Active Bacterial Core surveillance data to identify breakthrough infections (vaccine-type IPD in children receiving ≥1 7-valent pneumococcal conjugate vaccine [PCV7] or 13-valent pneumococcal conjugate vaccine [PCV13] dose) among children aged <5 years. We estimated schedule-specific IPD incidence rates (IRs) per 100 000 person-years and compared incidence by schedule (2 + 1 vs 3 + 1; 2 + 0 vs 3 + 0) using rate differences (RDs) and incidence rate ratios. RESULTS We identified 71 PCV7 and 49 PCV13 breakthrough infections among children receiving a schedule of interest. PCV13 breakthrough infection rates were higher in children aged <1 year receiving the 2 + 0 (IR: 7.8) vs 3 + 0 (IR: 0.6) schedule (incidence rate ratio: 12.9; 95% confidence interval: 4.1-40.4); PCV7 results were similar. Differences in PCV13 breakthrough infection rates by schedule in children aged <1 year were larger in 2010-2011 (2 + 0 IR: 18.6; 3 + 0 IR: 1.4; RD: 16.6) vs 2012-2016 (2 + 0 IR: 3.6; 3 + 0 IR: 0.2; RD: 3.4). No differences between schedules were detected in children aged ≥1 year for PCV13 breakthrough infections. CONCLUSIONS Fewer PCV breakthrough infections occurred in the first year of life with 3 primary doses. Differences in breakthrough infection rates by schedule decreased as vaccine serotypes decreased in circulation.
Collapse
Affiliation(s)
- Tolulope A. Adebanjo
- Epidemic Intelligence Service and,National Center for Immunization and Respiratory
Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - David Yankey
- National Center for Immunization and Respiratory
Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Holly A. Hill
- National Center for Immunization and Respiratory
Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | | | - Meghan Barnes
- Colorado Department of Public Health and Environment,
Denver, Colorado
| | - Susan Petit
- Connecticut Department of Public Health, Hartford,
Connecticut
| | - Monica Farley
- School of Medicine, Emory University and Atlanta
Department of Veterans Affairs Medical Center, Atlanta, Georgia
| | - Lee H. Harrison
- Bloomberg School of Public Health, Johns Hopkins
University, Baltimore, Maryland
| | | | - Joan Baumbach
- New Mexico Department of Health, Santa Fe, New
Mexico
| | - Nancy Bennett
- School of Medicine and Dentistry, University of
Rochester, Rochester, New York
| | | | - Ann Thomas
- Oregon Public Health Division, Portland, Oregon;
and
| | | | - Bernard Beall
- National Center for Immunization and Respiratory
Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Cynthia G. Whitney
- National Center for Immunization and Respiratory
Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Tamara Pilishvili
- National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia;
| |
Collapse
|
6
|
Dagan R. Relationship between immune response to pneumococcal conjugate vaccines in infants and indirect protection after vaccine implementation. Expert Rev Vaccines 2019; 18:641-661. [PMID: 31230486 DOI: 10.1080/14760584.2019.1627207] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Introduction: Streptococcus pneumoniae is a leading cause of morbidity and mortality worldwide. Widespread infant vaccination with pneumococcal conjugate vaccines (PCVs) substantially reduced vaccine-serotype pneumococcal disease by direct protection of immunized children and indirect protection of the community via decreased nasopharyngeal carriage and transmission. Essential to grasping the public health implications of pediatric PCV immunization is an understanding of how PCV formulations impact carriage. Areas covered: Using clinical evidence, this review examines how the immune response to PCVs is associated with subsequent nasopharyngeal carriage reduction in vaccinated infants and toddlers. By combining direct and indirect protection, carriage reduction results in a reduced spread of vaccine serotypes, and eventually, a decrease in vaccine serotype disease incidence in community members of all ages. Expert opinion: The current review presents some of the aspects that influence the overall impact of PCVs on vaccine-serotype carriage, and thus, spread. The link between reduction of vaccine-serotype carriage and the eventual reduction of vaccine-serotype disease in the wider community is described by comparing data from current PCVs, specifically with respect to their ability to reduce carriage of some cross-reacting serotypes (i.e. 6A versus 6B and 19A versus 19F).
Collapse
Affiliation(s)
- Ron Dagan
- a The Faculty of Health Sciences , Ben-Gurion University of the Negev , Beer-Sheva , Israel
| |
Collapse
|
7
|
Yang A, Cai F, Lipsitch M. Herd immunity alters the conditions for performing dose schedule comparisons: an individual-based model of pneumococcal carriage. BMC Infect Dis 2019; 19:227. [PMID: 30836941 PMCID: PMC6402138 DOI: 10.1186/s12879-019-3833-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 02/19/2019] [Indexed: 12/05/2022] Open
Abstract
Background There is great interest in the use of reduced dosing schedules for pneumococcal conjugate vaccines, a strategy premised on maintaining an acceptable level of protection against disease and carriage of the organism. We asked about the practicality of measuring differential effectiveness against carriage in a population with and without widespread use of the vaccine for infants. Methods We adapted an existing transmission-dynamic, individual-based stochastic model fitted to the prevaccine epidemiology of pneumococcal carriage in the United States, and compared the observed vaccine-type carriage prevalence in different arms of a simulated trial with one, two, or three infant doses plus a 12-month booster. Using these simulations, we calculated vaccine efficacy that would be estimated at different times post-enrollment in the trial and calculated required sample sizes to see a difference in carriage prevalence. Results In a pneumococcal conjugate vaccine (PCV)-naïve population, the difference in vaccine-type (VT) pneumococcal carriage prevalence between trial arms was less than 7% and varied with sampling time. In a population already receiving routine PCV administration, VT pneumococcal prevalence is nearly indistinguishable between trial arms. Relative efficacy of different dosing schedules was strongly dependent on the time between enrollment and sampling, with maximal prevalence differences reached 1–3 years post-enrollment. Moreover, vaccine efficacy estimates were typically slightly higher in trials in communities already receiving vaccination. Despite this, much larger sample sizes—by more than an order of magnitude—are required for a vaccine trial conducted in a population receiving routine PCV administration as compared to in a PCV-naïve population. Conclusions These findings highlight some underappreciated aspects of clinical trials of pneumococcal conjugate vaccines with efficacy endpoints, such as the context- and time-dependence of efficacy estimates. They support the wisdom of conducting comparative dose schedule trials of conjugate vaccine effects on carriage in vaccine-naïve populations. Electronic supplementary material The online version of this article (10.1186/s12879-019-3833-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Alan Yang
- Harvard University, 677 Huntington Ave, Kresge Building, Room 506G, Boston, MA, 02115, USA.
| | - Francisco Cai
- Harvard T.H. Chan School of Public Health, 677 Huntington Ave, Kresge Building, Room 506G, Boston, MA, 02115, USA
| | - Marc Lipsitch
- Harvard T.H. Chan School of Public Health, 677 Huntington Ave, Kresge Building, Room 506G, Boston, MA, 02115, USA
| |
Collapse
|
8
|
Dagan R, Ben-Shimol S, Simell B, Greenberg D, Porat N, Käyhty H, Givon-Lavi N. A toddler PCV booster dose following 3 infancy priming doses increases circulating serotype-specific IGG levels but does not increase protection against carriage. Vaccine 2018; 36:2774-2782. [DOI: 10.1016/j.vaccine.2018.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 03/30/2018] [Accepted: 04/03/2018] [Indexed: 11/28/2022]
|
9
|
Nasopharyngeal Pneumococcal Colonization and Impact of a Single Dose of 13-Valent Pneumococcal Conjugate Vaccine in Indian Children With HIV and Their Unvaccinated Parents. Pediatr Infect Dis J 2018; 37:451-458. [PMID: 28961675 DOI: 10.1097/inf.0000000000001800] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Human immunodeficiency virus (HIV) infection increases risk of invasive disease from Streptococcus pneumoniae. Pneumococcal conjugate vaccines (PCV) prevent invasive disease and acquisition of vaccine type (VT) pneumococcus in the nasopharynx. OBJECTIVE To look at the safety and impact of one dose of PCV13 on acquisition of VT pneumococcal carriage in Indian children with HIV. METHOD We conducted a cohort study in families of HIV-infected children (CLH) and families of HIV-uninfected children (HUC) in West Bengal. All children received one dose of PCV13. Nasopharyngeal swabs were collected from children and parents at baseline and 2 months after vaccination. RESULT One hundred and fifteen CLH and 47 HUC received one dose of PCV13. Fifty-eight percent of CLH were on antiretroviral therapy (ART), and the median nadir CD4 count was 287. There were no significant adverse events in either group. HUC had more VT colonization than CLH-55% versus 23% of all pneumococcal isolates. HIV infection doubled the risk of nonvaccine serotype colonization (P = 0.03). There was no difference in acquisition of VT isolates in CLH (4.4%) and HUC (4.5%) post-PCV13; however, older CLH (>5 years) had decreased clearance of VT strains. ART made no difference in pneumococcal colonization at baseline or after PCV13; however, CLH with higher nadir CD4 counts before starting ART were less likely to have VT colonization post-PCV13 (prevalence ratio, 0.2; 95% confidence interval: 0.1-0.5). CONCLUSION While there was no difference in acquisition of VT nasopharyngeal carriage of pneumococcus in CLH and HUC after one dose of PCV13, earlier access to ART may impact response to PCV13 in CLH.
Collapse
|
10
|
Kinetics of antibodies against pneumococcal proteins and their relationship to nasopharyngeal carriage in the first two months of life. PLoS One 2017; 12:e0185824. [PMID: 28982123 PMCID: PMC5628860 DOI: 10.1371/journal.pone.0185824] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 09/20/2017] [Indexed: 12/25/2022] Open
Abstract
Introduction The currently used Streptococcus pneumoniae vaccines have had a significant impact on the pneumococcal diseases caused by the serotypes they cover. Their limitations have stimulated a search for alternate vaccines that will cover all serotypes, be affordable and effective in young children. Pneumococcal protein antigens are potential vaccine candidates that may meet some of the shortfalls of the current vaccines. Thus, this study aimed to determine the relationship between antibodies against pneumococcal protein antigens and nasopharyngeal carriage in infants. Methods One hundred and twenty mother-infant pairs were enrolled into the study. They had nasopharyngeal swabs(NPS) taken at birth and every two weeks for the first eight weeks after delivery, and blood samples were obtained at birth and every four weeks for the first eight weeks after delivery. Nasopharyngeal carriage of S. pneumoniae was determined from the NPS and antibodies against the pneumococcal proteins CbpA, PspA and rPly were measured in the blood samples. Results The S. pneumoniae carriage rate in infants increased to that of mothers by eight weeks of age. The odds of carriage in infants was 6.2 times (95% CI: 2.0–18.9) higher when their mothers were also carriers. Bacterial density in infants was lower at birth compared to their mothers (p = 0.004), but increased with age and became higher than that of their mothers at weeks 4 (p = 0.009), 6 (p = 0.002) and 8 (p<0.0001). At birth, the infants’ antibodies against CbpA, and rPly pneumococcal protein antigens were similar, but that of PspA was lower (p<0.0001), compared to their mothers. Higher antibody concentrations to CbpA [OR (95% CI): 0.49 (0.26–0.92, p = 0.03)], but not PspA and rPly, were associated with protection against carriage in the infants. Conclusion Naturally induced antibodies against the three pneumococcal protein antigens were transferred from mother to child. The proportion of infants with nasopharyngeal carriage and the bacterial density of S. pneumoniae increased with age within the first eight weeks of life. Higher concentrations of antibodies against CbpA, but not PspA and rPly, were associated with reduced risk of nasopharyngeal carriage of S. pneumoniae in infants.
Collapse
|
11
|
Sáez-Llorens X, Rowley S, Wong D, Rodríguez M, Calvo A, Troitiño M, Salas A, Vega V, Castrejón MM, Lommel P, Pascal TG, Hausdorff WP, Borys D, Ruiz-Guiñazú J, Ortega-Barría E, Yarzabal JP, Schuerman L. Efficacy of 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine against acute otitis media and nasopharyngeal carriage in Panamanian children - A randomized controlled trial. Hum Vaccin Immunother 2017; 13:1-16. [PMID: 28368738 PMCID: PMC5489287 DOI: 10.1080/21645515.2017.1287640] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
We previously reported 10-valent pneumococcal non-typeable Haemophilus influenzae (NTHi) protein D conjugate vaccine (PHiD-CV) efficacy in a double-blind randomized trial (ClinicalTrials.gov: NCT00466947) against various diseases, including acute otitis media (AOM). Here, we provide further analyses. In the Panamanian subset, 7,359 children were randomized (1:1) to receive PHiD-CV or control vaccine at age 2/4/6 and 15–18 months. Of these, 2,000 had nasopharyngeal swabs collected. AOM cases were captured when parents sought medical attention for children with AOM symptoms; surveillance was enhanced approximately 2 y into the study through regular telephone calls or home visits by study personnel, who advised parents to visit the clinic if their child had AOM symptoms. Mean follow-up was 31.4 months. Clinical AOM (C-AOM) cases were assessed by physicians and confirmed by otorhinolaryngologists. Middle ear fluid samples, taken from children with C-AOM after specific informed consent, and nasopharyngeal samples were cultured for pathogen identification. For 7,359 children, 2,574 suspected AOM cases were assessed by a primary healthcare physician; 649 cases were C-AOM cases as per protocol definition. From the 503 MEF samples collected, 158 resulted in a positive culture. In the intent-to-treat cohort (7,214 children), PHiD-CV showed VE against first C-AOM (24.0% [95% CI: 8.7, 36.7]) and bacterial (B-AOM) episodes (48.0% [20.3, 66.1]) in children <24 months, which declined thereafter with age. Pre-booster VE against C-AOM was 30.7% [12.9, 44.9]; post-booster, −6.7% [−36.4, 16.6]. PHiD-CV VE was 17.7% [−6.1, 36.2] against moderate and 32.7% [−20.5, 62.4] against severe C-AOM. VE against vaccine-serotype pneumococcal NPC was 31.2% [5.3, 50.3] 3 months post-booster, and 25.6% [12.7, 36.7] across all visits. NTHi colonization rates were low and no significant reduction was observed. PHiD-CV showed efficacy against C-AOM and B-AOM in children younger than 24 months, and reduced vaccine-serotype NPC.
Collapse
Affiliation(s)
- Xavier Sáez-Llorens
- a Department of Infectious Diseases , Hospital del Niño, Panama City, Panama; Distinguished Member of the SNI , Senacyt , Panama
| | - Stella Rowley
- b Department of Otorhinolaryngology Hospital del Niño , Panama City , Panama
| | - Digna Wong
- c Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT) , Panama City , Panama
| | - Mirna Rodríguez
- c Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT) , Panama City , Panama
| | - Arlene Calvo
- d Health Research International , Panama City , Panama
| | | | - Albino Salas
- d Health Research International , Panama City , Panama
| | - Vielka Vega
- d Health Research International , Panama City , Panama
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Nicholls TR, Leach AJ, Morris PS. The short-term impact of each primary dose of pneumococcal conjugate vaccine on nasopharyngeal carriage: Systematic review and meta-analyses of randomised controlled trials. Vaccine 2015; 34:703-13. [PMID: 26742947 DOI: 10.1016/j.vaccine.2015.12.048] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/16/2015] [Accepted: 12/17/2015] [Indexed: 01/20/2023]
Abstract
BACKGROUND Early onset of persistent otitis media is a priority issue for Australian Indigenous populations. The objective is to determine the direct and short-term impact of one, two and three doses of any pneumococcal conjugate vaccine (PCV) formulation on nasopharyngeal (NP) carriage of Streptococcus pneumoniae (Spn) and non-typeable Haemophilus influenzae (NTHi), the otopathogens targeted by current PCVs. METHODS We searched MEDLINE (PubMed) and CENTRAL (Cochrane Library) to 29 September 2015. We also scanned reference lists of recent reviews and contacted authors. We included randomised controlled trials (RCTs) with a PCV schedule commencing ≤3 months of age that reported controlled non-cumulative group-specific prevalence data for carriage of Spn or NTHi at age<12 months. We performed a standard risk of bias assessment. We estimated the pooled relative risk (RR) and 95% confidence interval (95%CI) for each vaccine dose on NP carriage by meta-analysis. RESULTS We included 16 RCTs involving 14,776 participants. The PCVs were conjugated to diphtheria toxin CRM197, diphtheria toxoid, tetanus toxoid or NTHi protein D and varied in valency (4-13). Controls were non-PCVs, placebo or no vaccine. The earliest carriage outcome was from 2 to 9 months of age. Compared to controls, there were no significant differences between one or two doses of PCV on vaccine-type (VT) pneumococcal carriage at ∼4 and ∼6 months respectively. However, VT carriage was significantly lower at ∼7 months RR 0.67 95%CI 0.56-0.81 from 9 studies and 7613 infants and non-vaccine type (NVT) carriage was higher RR 1.23 95%CI 1.09-1.40 from 8 studies and 5861 infants. No impact on overall pneumococcal or NTHi carriage was found. CONCLUSIONS The primary PCV schedule had no significant short-term impact on overall pneumococcal or NTHi NP carriage and a limited impact on VT pneumococcal carriage before the third dose.
Collapse
Affiliation(s)
- Thomas Rodger Nicholls
- Menzies School of Health Research, Charles Darwin University, John Matthews Building (58), Royal Darwin Hospital Campus, Darwin 0810, NT, Australia
| | - Amanda Jane Leach
- Menzies School of Health Research, Charles Darwin University, John Matthews Building (58), Royal Darwin Hospital Campus, Darwin 0810, NT, Australia.
| | - Peter Stanley Morris
- Menzies School of Health Research, Charles Darwin University, John Matthews Building (58), Royal Darwin Hospital Campus, Darwin 0810, NT, Australia
| |
Collapse
|
13
|
Scott P, Herzog SA, Auranen K, Dagan R, Low N, Egger M, Heijne JC. Timing of bacterial carriage sampling in vaccine trials: A modelling study. Epidemics 2014; 9:8-17. [DOI: 10.1016/j.epidem.2014.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 05/08/2014] [Accepted: 08/18/2014] [Indexed: 10/24/2022] Open
|
14
|
Adegbola RA, DeAntonio R, Hill PC, Roca A, Usuf E, Hoet B, Greenwood BM. Carriage of Streptococcus pneumoniae and other respiratory bacterial pathogens in low and lower-middle income countries: a systematic review and meta-analysis. PLoS One 2014; 9:e103293. [PMID: 25084351 PMCID: PMC4118866 DOI: 10.1371/journal.pone.0103293] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 06/27/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Infection with Streptococcus pneumoniae is a major cause of childhood morbidity and mortality worldwide, especially in low income countries where pneumococcal conjugate vaccines (PCVs) are still underused. In countries where PCVs have been introduced, much of their efficacy has resulted from their impact on nasopharyngeal carriage in vaccinated children. Understanding the epidemiology of carriage for S. pneumoniae and other common respiratory bacteria in developing countries is crucial for implementing appropriate vaccination strategies and evaluating their impact. METHODS AND FINDINGS We have systematically reviewed published studies reporting nasopharyngeal or oropharyngeal carriage of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Neisseria meningitidis in children and adults in low and lower-middle income countries. Studies reporting pneumococcal carriage for healthy children <5 years of age were selected for a meta-analysis. The prevalences of carriage for S. pneumoniae, H. influenzae, and M. catarrhalis were generally higher in low income than in lower-middle income countries and were higher in young children than in adults. The prevalence of S. aureus was high in neonates. Meta-analysis of data from young children before the introduction of PCVs showed a pooled prevalence estimate of 64.8% (95% confidence interval, 49.8%-76.1%) in low income countries and 47.8% (95% confidence interval, 44.7%-50.8%) in lower-middle income countries. The most frequent serotypes were 6A, 6B, 19A, 19F, and 23F. CONCLUSIONS In low and lower-middle income countries, pneumococcal carriage is frequent, especially in children, and the spectrum of serotypes is wide. However, because data are limited, additional studies are needed to adequately assess the impact of PCV introduction on carriage of respiratory bacteria in these countries.
Collapse
Affiliation(s)
| | | | - Philip C. Hill
- Medical Research Council Unit, Banjul, The Gambia
- Centre for International Health, School of Medicine, University of Otago, Dunedin, New Zealand
| | - Anna Roca
- Medical Research Council Unit, Banjul, The Gambia
| | - Effua Usuf
- Medical Research Council Unit, Banjul, The Gambia
| | | | - Brian M. Greenwood
- Faculty of Infectious & Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| |
Collapse
|
15
|
Mackenzie GA, Bottomley C, van Hoek AJ, Jeffries D, Ota M, Zaman SMA, Greenwood B, Cutts F. Efficacy of different pneumococcal conjugate vaccine schedules against pneumonia, hospitalisation, and mortality: re-analysis of a randomised trial in the Gambia. Vaccine 2014; 32:2493-500. [PMID: 24631086 DOI: 10.1016/j.vaccine.2014.02.081] [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] [Received: 11/05/2013] [Revised: 02/12/2014] [Accepted: 02/25/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Pneumococcal conjugate vaccines (PCV) reduce disease due to Streptococcus pneumoniae. We aimed to determine the efficacy of different PCV schedules in Gambian children. METHODS We reanalysed data from a randomised placebo-controlled trial. Infants aged 6-51 weeks were allocated to three doses of nine-valent PCV (n=8718) or placebo (n=8719) and followed until age 30 months. We categorised participants to compare: (a) a first dose at age 6 or 10 weeks, (b) intervals of 1 or 2 months between doses, and (c) different intervals between second and third doses. The primary endpoint was first episode of radiologic pneumonia; other endpoints were hospitalisation and mortality. Using the placebo group as the reference population, Poisson regression models were used with follow-up after the first dose to estimate the efficacy of each schedule and from age 6 weeks to estimate the incidence rate difference between schedules. RESULTS Predicted efficacy in the groups aged 6 weeks (n=2467, 154 events) or 10 weeks (n=2420, 106 events) at first dose against radiologic pneumonia were 32% (95% CI 19-43%) and 33% (95% CI 21-44%), against hospitalisation 14% (95% CI 3-23%) and 17% (95% CI 7-26%), and against mortality 17% (95% CI -3 to 33%) and 16% (95% CI -3 to 32%) respectively. Predicted efficacy in the groups with intervals of 1 month (n=2701, 133 events) or 2 months (n=1351, 58 events) between doses against radiologic pneumonia were 33% (95% CI 20-44%) and 36% (95% CI 24-46%), against hospitalisation 15% (95% CI 5-24%) and 18% (95% CI 8-27%), and against mortality 17% (95% CI -2 to 33%) and 13% (95% CI -8 to 29%) respectively. Efficacy did not differ by interval between second and third doses, nor did the incidence rate difference between schedules. CONCLUSIONS We found no evidence that efficacy or effectiveness of PCV9 differed when doses were given with modest variability around the scheduled ages or intervals between doses.
Collapse
Affiliation(s)
- Grant A Mackenzie
- Medical Research Council (UK), The Gambia Unit, Fajara, PO Box 273, Banjul, The Gambia.
| | - Christian Bottomley
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | | | - David Jeffries
- Medical Research Council (UK), The Gambia Unit, Fajara, PO Box 273, Banjul, The Gambia.
| | - Martin Ota
- Medical Research Council (UK), The Gambia Unit, Fajara, PO Box 273, Banjul, The Gambia.
| | - Syed M A Zaman
- Public Health England, 61 Colindale Avenue, London, NW9 5EQ, UK.
| | - Brian Greenwood
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Felicity Cutts
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| |
Collapse
|
16
|
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.
Collapse
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
| |
Collapse
|
17
|
Systematic review of the effect of pneumococcal conjugate vaccine dosing schedules on vaccine-type nasopharyngeal carriage. Pediatr Infect Dis J 2014; 33 Suppl 2:S152-60. [PMID: 24336057 PMCID: PMC3940522 DOI: 10.1097/inf.0000000000000083] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Pneumococcal conjugate vaccines (PCV) reduce nasopharyngeal carriage of vaccine type (VT) pneumococci, an important driver of vaccine programs' overall benefits. The dosing schedule that best reduces carriage is unclear. METHODS We performed a systematic review of English language publications from 1994 to 2010 (supplemented post hoc with studies from 2011) reporting PCV effects on VT carriage to assess variability in effect by dosing schedule. RESULTS We identified 32 relevant studies (36 citations) from 12,980 citations reviewed. Twenty-one (66%) evaluated PCV7; none used PCV10 or PCV13. Five studies evaluated 2 primary doses and 13 three primary doses. After the first year of life, 14 evaluated 3-dose primary series with PCV booster (3+1), seven 3 doses plus 23-valent polysaccharide booster "3+1PPV23," five "3+0," four "2+1," three "2+1PPV23" and two "2+0." Four studies directly compared schedules. From these, 3 primary doses reduced VT carriage more than 2 doses at 1-7 months following the series (1 study significant; 2 borderline). In a study, the 2+1 schedule reduced VT carriage more than 2+0 at 18, but not at 24 months of age. One study of a 23-valent pneumococcal polysaccharide vaccine booster showed no effect. All 16 clinical trials with unvaccinated controls and 11 observational studies with before-after designs showed reduction in VT carriage. CONCLUSIONS The available literature demonstrates VT-carriage reduction for 2+0, 2+1, 3+0 and 3+1 PCV schedules, but not for 23-valent pneumococcal polysaccharide vaccine booster. Comparisons between schedules show that 3 primary doses and a 2+1 schedule may reduce carriage more than 2 primary doses and a 2+0 schedule, respectively.
Collapse
|
18
|
Conklin L, Loo JD, Kirk J, Fleming-Dutra KE, Deloria Knoll M, Park DE, Goldblatt D, O'Brien KL, Whitney CG. Systematic review of the effect of pneumococcal conjugate vaccine dosing schedules on vaccine-type invasive pneumococcal disease among young children. Pediatr Infect Dis J 2014; 33 Suppl 2:S109-18. [PMID: 24336053 PMCID: PMC3944481 DOI: 10.1097/inf.0000000000000078] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Pneumococcal conjugate vaccines (PCV) are being implemented globally using a variety of different schedules. The optimal schedule to maximize protection of vaccinated children against vaccine-type invasive pneumococcal disease (VT-IPD) is not known. METHODS To assess the relative benefit of various PCV dosing schedules, we conducted a systematic review of studies published in English from 1994 to 2010 (supplemented post hoc with studies from 2011) on PCV effectiveness against VT-IPD among children targeted to receive vaccine. Data on 2-dose and 3-dose primary series, both with and without a booster ("2+0," "2+1," "3+0" and "3+1"), were included. For observational studies using surveillance data or case counts, we calculated percentage reduction in VT-IPD before and after PCV introduction. RESULTS Of 4 randomized controlled trials and 31 observational studies reporting VT-IPD among young children, none evaluated a 2+0 complete series, 7 (19%) evaluated 2+1, 4 (11%) 3+0 and 27 (75%) 3+1. Most (86%) studies were from North America or Europe. Only 1 study (observational) directly compared 2 schedules (3+0 vs. 3+1); results supported the use of a booster dose. In clinical trials, vaccine efficacy ranged from 65% to 71% with 3+0 and 83% to 94% with 3+1. Surveillance data and case counts demonstrate reductions in VT-IPD of up to 100% with 2+1 (6 studies) or 3+1 (17 studies) schedules and up to 90% with 3+0 (2 studies). Reductions were observed as early as 1 year after PCV introduction. CONCLUSIONS These data support the use of 2+1, 3+0 and 3+1 schedules, although most data of PCV impact on VT-IPD among young children are from high-income countries using 3+1. Differences between schedules for impact on VT-IPD are difficult to discern based on available data.
Collapse
Affiliation(s)
- Laura Conklin
- From the *Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA; †Westat Inc., Rockville, MD; ‡Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA; §International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; and ¶Institute for Child Health, University College London, London, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Whitney CG, Goldblatt D, O'Brien KL. Dosing schedules for pneumococcal conjugate vaccine: considerations for policy makers. Pediatr Infect Dis J 2014; 33 Suppl 2:S172-81. [PMID: 24336059 PMCID: PMC3940379 DOI: 10.1097/inf.0000000000000076] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Since second generation pneumococcal conjugate vaccines (PCVs) targeting 10 and 13 serotypes became available in 2010, the number of national policy makers considering these vaccines has steadily increased. An important consideration for a national immunization program is the timing and number of doses-the schedule-that will best prevent disease in the population. Data on disease epidemiology and the efficacy or effectiveness of PCV schedules are typically considered when choosing a schedule. Practical concerns, such as the existing vaccine schedule, and vaccine program performance are also important. In low-income countries, pneumococcal disease and deaths typically peak well before the end of the first year of life, making a schedule that provides PCV doses early in life (eg, a 6-, 10- and 14-week schedule) potentially the best option. In other settings, a schedule including a booster dose may address disease that peaks in the second year of life or may be seen to enhance a schedule already in place. A large and growing body of evidence from immunogenicity studies, as well as clinical trials and observational studies of carriage, pneumonia and invasive disease, has been systematically reviewed; these data indicate that schedules of 3 or 4 doses all work well, and that the differences between these regimens are subtle, especially in a mature program in which coverage is high and indirect (herd) effects help enhance protection provided directly by a vaccine schedule. The recent World Health Organization policy statement on PCVs endorsed a schedule of 3 primary doses without a booster or, as a new alternative, 2 primary doses with a booster dose. While 1 schedule may be preferred in a particular setting based on local epidemiology or practical considerations, achieving high coverage with 3 doses is likely more important than the specific timing of doses.
Collapse
Affiliation(s)
- Cynthia G Whitney
- From the *Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, †Institute for Child Health, London, United Kingdom; and ‡International Vaccine Access Center, Johns Hopkins University School of Public Health, Baltimore, MD
| | | | | |
Collapse
|
20
|
Park DE, Johnson TS, Nonyane BAS, Chandir S, Conklin L, Fleming-Dutra KE, Loo JD, Goldblatt D, Whitney CG, O'Brien KL, Deloria Knoll M. The differential impact of coadministered vaccines, geographic region, vaccine product and other covariates on pneumococcal conjugate vaccine immunogenicity. Pediatr Infect Dis J 2014; 33 Suppl 2:S130-9. [PMID: 24336055 PMCID: PMC3944480 DOI: 10.1097/inf.0000000000000081] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Antipneumococcal capsular polysaccharide antibody concentrations are used as predictors of vaccine efficacy against vaccine serotype (ST) pneumococcal disease among infants. While pneumococcal conjugate vaccines (PCV) are recommended globally, factors associated with optimal PCV immune response are not well described. We aimed to systematically assess local setting factors, beyond dosing schedule, which may affect PCV antibody levels. METHODS We conducted a literature review of PCV immunogenicity, abstracting data from published reports, unpublished sources, and conference abstracts from 1994 to 2010 (and ad hoc 2011 reports). Studies included in this analysis evaluated ≥ 2 primary doses of PCV before 6 months of age in non-high-risk populations, used 7-valent or higher PCV products (excluding Aventis-Pasteur and Merck products) and provided information on geometric mean concentration (GMC) for STs 1, 5, 6B, 14, 19F or 23F. Using random effects meta-regression, we assessed the impact of geographic region, coadministered vaccines and PCV product on postprimary GMC, adjusting for dosing schedule and ELISA laboratory method. RESULTS Of 12,980 citations reviewed, we identified 103 vaccine study arms for this analysis. Children in studies from Asia, Africa and Latin America had significantly higher GMC responses compared with those in studies from Europe and North America. Coadministration with acellular pertussis DTP compared with whole-cell DTP had no effect on PCV immunogenicity except for ST14, where GMCs were higher when coadministered with acellular pertussis DTP. Vaccine product, number of PCV doses, dosing interval, age at first dose and ELISA laboratory method also affected the GMC. CONCLUSIONS PCV immunogenicity is associated with geographic region and vaccine product; however, the associations and magnitude varied by ST. Consideration of these factors is essential when comparing PCV immunogenicity results between groups and should be included in the evidence base when selecting optimal PCV vaccine schedules in specific settings.
Collapse
Affiliation(s)
- Daniel E Park
- From the *International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; †Biostatistics Consulting, Chicago, IL; ‡Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA; §Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA; and ¶Institute of Child Health, University College London, London, United Kingdom
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
BACKGROUND Despite the breadth of studies demonstrating benefits of pneumococcal conjugate vaccine (PCV), uncertainty remains regarding the optimal PCV dosing schedule in infants. METHODS We conducted a systematic literature review of PCV immunogenicity published from 1994 to 2010 (supplemented post hoc with studies from 2011). Studies included for analysis evaluated ≥2 doses of 7-valent or higher product (excluding Aventis-Pasteur PCV11) administered to nonhigh-risk infants ≤6 months of age. Impact of PCV schedule on geometric mean antibody concentration (GMC) and proportion of subjects over 0.35 mcg/mL were assessed at various time points; the GMC 1 month postdose 3 (for various dosing regimens) for serotypes 1, 5, 6B, 14, 19F and 23F was assessed in detail using random effects linear regression, adjusted for product, acellular diphtheria-tetanus-pertussis/whole-cell diphtheria- tetanus-pertussis coadministration, laboratory method, age at first dose and geographic region. RESULTS From 61 studies, we evaluated 13 two-dose (2+0) and 65 three-dose primary schedules (3+0) without a booster dose, 11 "2+1" (2 primary plus booster) and 42 "3+1" schedules. The GMC after the primary series was higher following 3-dose schedules compared with 2-dose schedules for all serotypes except for serotype 1. Pre- and postbooster GMCs were generally similar regardless of whether 2 or 3 primary doses were given. GMCs were significantly higher for all serotypes when dose 3 was administered in the second year (2+1) compared with ≤6 months of age (3+0). CONCLUSIONS While giving the third dose in the second year of life produces a higher antibody response than when given as part of the primary series in the first 6 months, the lower GMC between the 2-dose primary series and booster may result in less disease protection for infants in that interval than those who completed the 3-dose primary series. Theoretical advantages of higher antibodies induced by giving the third dose in the second year of life, such as increased protection against serotype 1 disease, longer duration of protection or more rapid induction of herd effects, need to be evaluated in practice.
Collapse
|
22
|
Bjarnarson SP, Benonisson H, Del Giudice G, Jonsdottir I. Pneumococcal polysaccharide abrogates conjugate-induced germinal center reaction and depletes antibody secreting cell pool, causing hyporesponsiveness. PLoS One 2013; 8:e72588. [PMID: 24069152 PMCID: PMC3771989 DOI: 10.1371/journal.pone.0072588] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 07/15/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Plain pneumococcal polysaccharide (PPS) booster administered during second year of life has been shown to cause hyporesponsiveness. We assessed the effects of PPS booster on splenic memory B cell responses and persistence of PPS-specific long-lived plasma cells in the bone marrow (BM). METHODS Neonatal mice were primed subcutanously (s.c.) or intranasally (i.n.) with pneumococcal conjugate (Pnc1-TT) and the adjuvant LT-K63, and boosted with PPS+LT-K63 or saline 1, 2 or 3 times with 16 day intervals. Seven days after each booster, spleens were removed, germinal centers (GC), IgM(+), IgG(+) follicles and PPS-specific antibody secreting cells (AbSC) in spleen and BM enumerated. RESULTS PPS booster s.c., but not i.n., compromised the Pnc1-TT-induced PPS-specific Abs by abrogating the Pnc1-TT-induced GC reaction and depleting PPS-specific AbSCs in spleen and limiting their homing to the BM. There was no difference in the frequency of PPS-specific AbSCs in spleen and BM between mice that received 1, 2 or 3 PPS boosters s.c.. Repeated PPS+LT-K63 booster i.n. reduced the frequency of PPS-specific IgG(+) AbSCs in BM. CONCLUSIONS PPS booster-induced hyporesponsiveness is caused by abrogation of conjugate-induced GC reaction and depletion of PPS-specific IgG(+) AbSCs resulting in no homing of new PPS-specific long-lived plasma cells to the BM or survival. These results should be taken into account in design of vaccination schedules where polysaccharides are being considered.
Collapse
Affiliation(s)
- Stefania P. Bjarnarson
- Landspitali, The National University Hospital of Iceland, Department of Immunology, Reykjavik, Iceland
- University of Iceland, Faculty of Medicine, Reykjavik, Iceland
| | - Hreinn Benonisson
- Landspitali, The National University Hospital of Iceland, Department of Immunology, Reykjavik, Iceland
- University of Iceland, Faculty of Medicine, Reykjavik, Iceland
| | | | - Ingileif Jonsdottir
- Landspitali, The National University Hospital of Iceland, Department of Immunology, Reykjavik, Iceland
- University of Iceland, Faculty of Medicine, Reykjavik, Iceland
- deCODE Genetics, Reykjavik, Iceland
- * E-mail:
| |
Collapse
|
23
|
Pomat WS, van den Biggelaar AHJ, Phuanukoonnon S, Francis J, Jacoby P, Siba PM, Alpers MP, Reeder JC, Holt PG, Richmond PC, Lehmann D. Safety and immunogenicity of neonatal pneumococcal conjugate vaccination in Papua New Guinean children: a randomised controlled trial. PLoS One 2013; 8:e56698. [PMID: 23451070 PMCID: PMC3579820 DOI: 10.1371/journal.pone.0056698] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 01/14/2013] [Indexed: 11/19/2022] Open
Abstract
Background Approximately 826,000 children, mostly young infants, die annually from invasive pneumococcal disease. A 6-10-14-week schedule of pneumococcal conjugate vaccine (PCV) is efficacious but neonatal PCV may provide earlier protection and better coverage. We conducted an open randomized controlled trial in Papua New Guinea to compare safety, immunogenicity and priming for memory of 7-valent PCV (PCV7) given in a 0-1-2-month (neonatal) schedule with that of the routine 1-2-3-month (infant) schedule. Methods We randomized 318 infants at birth to receive PCV7 in the neonatal or infant schedule or no PCV7. All infants received 23-valent pneumococcal polysaccharide vaccine (PPV) at age 9 months. Serotype-specific serum IgG for PCV7 (VT) serotypes and non-VT serotypes 2, 5 and 7F were measured at birth and 2, 3, 4, 9, 10 and 18 months of age. Primary outcomes were geometric mean concentrations (GMCs) and proportions with concentration ≥0.35 µg/ml of VT serotype-specific pneumococcal IgG at age 2 months and one month post-PPV. Results We enrolled 101, 105 and 106 infants, respectively, into neonatal, infant and control groups. Despite high background levels of maternally derived antibody, both PCV7 groups had higher GMCs than controls at age 2 months for serotypes 4 (p<0.001) and 9V (p<0.05) and at age 3 months for all VTs except 6B. GMCs for serotypes 4, 9V, 18C and 19F were significantly higher (p<0.001) at age 2 months in the neonatal (one month post-dose2 PCV7) than in the infant group (one month post-dose1 PCV7). PPV induced significantly higher VT antibody responses in PCV7-primed than unprimed infants, with neonatal and infant groups equivalent. High VT and non-VT antibody concentrations generally persisted to age 18 months. Conclusions PCV7 is well-tolerated and immunogenic in PNG neonates and young infants and induces immunologic memory to PPV booster at age 9 months with antibody levels maintained to age 18 months. Trial Registration ClinicalTrials.gov NCT00219401NCT00219401
Collapse
Affiliation(s)
- William S. Pomat
- Papua New Guinean Institute of Medical Research, Goroka, Papua New Guinea
- Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia
| | - Anita H. J. van den Biggelaar
- Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia
| | | | - Jacinta Francis
- Papua New Guinean Institute of Medical Research, Goroka, Papua New Guinea
| | - Peter Jacoby
- Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia
| | - Peter M. Siba
- Papua New Guinean Institute of Medical Research, Goroka, Papua New Guinea
| | - Michael P. Alpers
- Centre for International Health, Curtin University, Perth, Western Australia, Australia
| | - John C. Reeder
- Papua New Guinean Institute of Medical Research, Goroka, Papua New Guinea
- Burnet Institute, Melbourne, Victoria, Australia
| | - Patrick G. Holt
- Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia
| | - Peter C. Richmond
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | - Deborah Lehmann
- Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia
- * E-mail:
| | | |
Collapse
|
24
|
Completeness of reporting in randomized controlled trials of 3 vaccines: a review of adherence to the CONSORT checklist. Pediatr Infect Dis J 2012; 31:1286-94. [PMID: 22935870 DOI: 10.1097/inf.0b013e31827032bb] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Clear reporting of randomized controlled trials (RCTs) of vaccines is important for understanding results and assessing their validity. The CONsolidated Standards of Reporting Trials (CONSORT) statement provides guidance to help authors reporting RCTs. The objective was to assess the completeness of reporting of RCTs of vaccines based on the CONSORT 2010 checklist. METHODS We collected data about items required by the CONSORT checklist or specific to trials of vaccines. We used publications of RCTs identified in 3 systematic reviews of pneumococcal polysaccharide, pneumococcal conjugate and rotavirus vaccines. We included the first journal publication that reported clinical, carriage or immunological data for each trial and summarized results descriptively. RESULTS We included 70 publications from 19 journals. Of these, 14 publications (20%) stated in the title that the trial was randomized and 26 publications (37%) nominated at least 1 primary outcome. The method for generating the random allocation sequence was fully reported in 24 publications (34%), the method of allocation concealment in 9 publications (13%) and 30 publications (43%) included a flow diagram. Trial registration numbers were reported in all articles published in 2010 to 2011. Actual age at vaccination was reported in 20% of trials of childhood schedules. Eleven of 19 journals endorsed the CONSORT statement. CONCLUSIONS The reporting of RCTs of vaccines is incomplete, with important methodological details missing from most reports. Journals could play a leading role in implementing changes. Improved reporting would make publications of vaccine trials easier to find, the findings easier to interpret and aid the incorporation of findings into policy.
Collapse
|
25
|
Pittet LF, Posfay-Barbe KM. Pneumococcal vaccines for children: a global public health priority. Clin Microbiol Infect 2012; 18 Suppl 5:25-36. [PMID: 22862432 DOI: 10.1111/j.1469-0691.2012.03938.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pneumococcal conjugated vaccines have been recommended in children for over a decade in many countries worldwide. Here we review the development of pneumococcal vaccines with a focus on the two types currently available for children and their safety record. We discuss also the effect of vaccines, including the 13-valent pneumococcal conjugate vaccine, on invasive pneumococcal diseases in children, particularly bacteraemia, pneumonia and meningitis, as well as on mucosal disease and carriage. In regions where immunization was implemented in young children, the number of invasive pneumococcal diseases decreased significantly, not only in the target age group, but also in younger and much older subjects. Challenges and future perspectives regarding the development of new 'universal' vaccines, which could bypass the current problem of serotype-specific protection in a context of serotype replacement, are also discussed.
Collapse
Affiliation(s)
- L F Pittet
- Department of Paediatrics, Geneva University Hospitals and University of Geneva Medical School, Geneva, Switzerland
| | | |
Collapse
|
26
|
Dagan R, Givon-Lavi N, Porat N, Greenberg D. The effect of an alternative reduced-dose infant schedule and a second year catch-up schedule with 7-valent pneumococcal conjugate vaccine on pneumococcal carriage: A randomized controlled trial. Vaccine 2012; 30:5132-40. [DOI: 10.1016/j.vaccine.2012.05.059] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Revised: 04/29/2012] [Accepted: 05/23/2012] [Indexed: 10/28/2022]
|
27
|
Akinsola AK, Ota MOC, Enwere GC, Okoko BJ, Zaman SMA, Saaka M, Nsekpong ED, Odutola AA, Greenwood BM, Cutts FT, Adegbola RA. Pneumococcal antibody concentrations and carriage of pneumococci more than 3 years after infant immunization with a pneumococcal conjugate vaccine. PLoS One 2012; 7:e31050. [PMID: 22363544 PMCID: PMC3282700 DOI: 10.1371/journal.pone.0031050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Accepted: 12/30/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND A 9-valent pneumococcal conjugate vaccine (PCV-9), given in a 3-dose schedule, protected Gambian children against pneumococcal disease and reduced nasopharyngeal carriage of pneumococci of vaccine serotypes. We have studied the effect of a booster or delayed primary dose of 7-valent conjugate vaccine (PCV-7) on antibody and nasopharyngeal carriage of pneumococci 3-4 years after primary vaccination. METHODOLOGY/PRINCIPAL FINDINGS We recruited a subsample of children who had received 3 doses of either PCV-9 or placebo (controls) into this follow-up study. Pre- and post- PCV-7 pneumococcal antibody concentrations to the 9 serotypes in PCV-9 and nasopharyngeal carriage of pneumococci were determined before and at intervals up to 18 months post-PCV-7. We enrolled 282 children at a median age of 45 months (range, 38-52 months); 138 had received 3 doses of PCV-9 in infancy and 144 were controls. Before receiving PCV-7, a high proportion of children had antibody concentrations >0.35 µg/mL to most of the serotypes in PCV-9 (average of 75% in the PCV-9 and 66% in the control group respectively). The geometric mean antibody concentrations in the vaccinated group were significantly higher compared to controls for serotypes 6B, 14, and 23F. Antibody concentrations were significantly increased to serotypes in the PCV-7 vaccine both 6-8 weeks and 16-18 months after PCV-7. Antibodies to serotypes 6B, 9V and 23F were higher in the PCV-9 group than in the control group 6-8 weeks after PCV-7, but only the 6B difference was sustained at 16-18 months. There was no significant difference in nasopharyngeal carriage between the two groups. CONCLUSIONS/SIGNIFICANCE Pneumococcal antibody concentrations in Gambian children were high 34-48 months after a 3-dose primary infant vaccination series of PCV-9 for serotypes other than serotypes 1 and 18C, and were significantly higher than in control children for 3 of the 9 serotypes. Antibody concentrations increased after PCV-7 and remained raised for at least 18 months.
Collapse
Affiliation(s)
| | - Martin O. C. Ota
- Medical Research Council (MRC), The Gambia Unit, Banjul, The Gambia
| | - Godwin C. Enwere
- Medical Research Council (MRC), The Gambia Unit, Banjul, The Gambia
| | - Brown J. Okoko
- Medical Research Council (MRC), The Gambia Unit, Banjul, The Gambia
| | - Syed M. A. Zaman
- Medical Research Council (MRC), The Gambia Unit, Banjul, The Gambia
| | - Mark Saaka
- Medical Research Council (MRC), The Gambia Unit, Banjul, The Gambia
| | | | | | | | - Felicity T. Cutts
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | |
Collapse
|
28
|
Immunogenicity of pneumococcal conjugate vaccines in infants after two or three primary vaccinations: A systematic review and meta-analysis. Vaccine 2011; 29:9600-6. [DOI: 10.1016/j.vaccine.2011.09.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 09/05/2011] [Accepted: 09/06/2011] [Indexed: 11/22/2022]
|
29
|
Scott P, Rutjes AW, Bermetz L, Robert N, Scott S, Lourenço T, Egger M, Low N. Comparing pneumococcal conjugate vaccine schedules based on 3 and 2 primary doses: Systematic review and meta-analysis. Vaccine 2011; 29:9711-21. [DOI: 10.1016/j.vaccine.2011.07.042] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 07/08/2011] [Accepted: 07/11/2011] [Indexed: 11/25/2022]
|