Open AccessIncidence of invasive pneumococcal disease after introduction of the 13-valent conjugate pneumococcal vaccine in British Columbia: A retrospective cohort study
Author(s) -
Nirma Khatri Vadlamudi,
David M. Patrick,
Linda Hoang,
Manish Sadarangani,
Fawziah Marra
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0239848
Subject(s) - pneumococcal conjugate vaccine , medicine , incidence (geometry) , pneumococcal disease , poisson regression , serotype , cohort , pediatrics , pneumococcal infections , rate ratio , streptococcus pneumoniae , cohort study , immunology , confidence interval , population , environmental health , biology , antibiotics , microbiology and biotechnology , physics , optics
Background A significant reduction in invasive pneumococcal disease (IPD) has been reported, across all ages, following the implementation of 7-valent conjugate pneumococcal vaccine (PCV7) globally, as part of infant immunization programs. We explored the additional impact of PCV13 on IPD over a 14-year period. Methods Using provincial laboratory surveillance and hospitalization data (N = 5791), we calculated the annual incidence of IPD following the implementation of PCV13 vaccine. Poisson regression was used to evaluate changes in the overall incidence of IPD, and serotype-specific IPD between PCV7 (2004–10) and PCV13 (2011–2015) eras. Results Overall, IPD rates have seen a modest decline in the PCV13 compared to the PCV7 era (IRR 0.84; 95% CI: 0.79–0.89); this was seen in children ≤2 years of age, and the majority of the adult cohort. Rates of vaccine-type IPD (PCV7 and PCV13) also decreased in the PCV13 era. In contrast, IPD incidence related to non-PCV13 (IRR: 1.56; 95%CI:1.43–1.72) and non-vaccine serotypes (IRR: 2.12; 95%CI:1.84–2.45) increased in the PCV13 era compared to the PCV7 era. Conclusions A modest reduction in IPD from the PCV13 vaccine was observed, with gains limited to the immunized cohort and adults. However, a significant increase in non-vaccine serotypes emphasizes the need for continued surveillance.