The impact of PCV7/13 on the distribution of carried pneumococcal serotypes and on pilus prevalence; 14 years of repeated cross-sectional surveillance.
Carriage
Pilus-1
Pneumococcal conjugate vaccines
S. pneumoniae
Serotype replacement
Journal
Vaccine
ISSN: 1873-2518
Titre abrégé: Vaccine
Pays: Netherlands
ID NLM: 8406899
Informations de publication
Date de publication:
23 04 2020
23 04 2020
Historique:
received:
11
12
2019
revised:
26
02
2020
accepted:
05
03
2020
pubmed:
1
4
2020
medline:
28
4
2021
entrez:
1
4
2020
Statut:
ppublish
Résumé
S. pneumoniae carriage by children is a major source of pneumococcal transmission, and the initial step prior to infection. Pilus type 1, reported in ~30% of pneumococcal strains in the pre-vaccine era, contributes to pneumococcal colonization and virulence. In this study, we report the impact of the pneumococcal conjugate vaccine (PCV), PCV7/PCV13 sequential implementation on serotype distribution, and on the prevalence of piliated strains among carried pneumococci during the pre- and post-vaccine eras. During 2002-2016, 12 repeated cross-sectional surveillances of nasopharyngeal S. pneumoniae carriage were conducted among 8,473 children <5.5 years old visiting primary care physicians in Central Israel. Seven biannual surveillances in the pre-PCV period, 2 surveillances after PCV7 was licensed but before implementation in the National Immunization Plan, and 3 additional surveillances in the post-PCV period. S. pneumoniae serotype distribution and prevalence of piliated strains were assessed. Carriage of S. pneumoniae was relatively stable (45.4%). The prevalence of serotypes included in PCV13 was 65.7%, in the pre-vaccine period and the pilus was present in 26.4% of isolates. The distribution of serotypes and the pilus prevalence in the pre-PCV period was relatively stable except for a decrease in prevalence of piliated 19F, observed following the first study year. Following PCV7/PCV13 implementation, vaccine type 13 (VT13) strains were nearly eliminated to 3.3% by 2016. Piliated strains, which were primarily of VT13 serotypes, initially followed a similar trend and were nearly eliminated by 2014 (1.7%). Yet, two years later, pilus prevalence re-emerged among non-VT strains to 12.8% of all pneumococci. Following PCV implementation, a dramatic and rapid decrease in VT strains prevalence was observed with a concomitant increase in non-VT strains. Piliated strains were nearly eliminated, yet re-emerged 7 years following PCV7/PCV13 implementation in various non-VT strains. This suggests that the pilus confers an advantage in colonization.
Sections du résumé
BACKGROUND
S. pneumoniae carriage by children is a major source of pneumococcal transmission, and the initial step prior to infection. Pilus type 1, reported in ~30% of pneumococcal strains in the pre-vaccine era, contributes to pneumococcal colonization and virulence. In this study, we report the impact of the pneumococcal conjugate vaccine (PCV), PCV7/PCV13 sequential implementation on serotype distribution, and on the prevalence of piliated strains among carried pneumococci during the pre- and post-vaccine eras.
METHODS
During 2002-2016, 12 repeated cross-sectional surveillances of nasopharyngeal S. pneumoniae carriage were conducted among 8,473 children <5.5 years old visiting primary care physicians in Central Israel. Seven biannual surveillances in the pre-PCV period, 2 surveillances after PCV7 was licensed but before implementation in the National Immunization Plan, and 3 additional surveillances in the post-PCV period. S. pneumoniae serotype distribution and prevalence of piliated strains were assessed.
RESULTS
Carriage of S. pneumoniae was relatively stable (45.4%). The prevalence of serotypes included in PCV13 was 65.7%, in the pre-vaccine period and the pilus was present in 26.4% of isolates. The distribution of serotypes and the pilus prevalence in the pre-PCV period was relatively stable except for a decrease in prevalence of piliated 19F, observed following the first study year. Following PCV7/PCV13 implementation, vaccine type 13 (VT13) strains were nearly eliminated to 3.3% by 2016. Piliated strains, which were primarily of VT13 serotypes, initially followed a similar trend and were nearly eliminated by 2014 (1.7%). Yet, two years later, pilus prevalence re-emerged among non-VT strains to 12.8% of all pneumococci.
CONCLUSIONS
Following PCV implementation, a dramatic and rapid decrease in VT strains prevalence was observed with a concomitant increase in non-VT strains. Piliated strains were nearly eliminated, yet re-emerged 7 years following PCV7/PCV13 implementation in various non-VT strains. This suggests that the pilus confers an advantage in colonization.
Identifiants
pubmed: 32224005
pii: S0264-410X(20)30360-1
doi: 10.1016/j.vaccine.2020.03.016
pii:
doi:
Substances chimiques
Heptavalent Pneumococcal Conjugate Vaccine
0
Pneumococcal Vaccines
0
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
3591-3599Informations de copyright
Copyright © 2020 Elsevier Ltd. All rights reserved.
Déclaration de conflit d'intérêts
Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: MK, HR, AC, HJ, SM, CR and DD - None. GR has served as a scientific consultant for MSD, AstraZeneca, Pfizer and Astellas. GRY has served a scientific consultant of Pfizer, Astellas, Neopharm, Teva and ClearOrr and received research support from Pfizer and GSK.