Incidence of invasive pneumococcal disease after introduction of the 13-valent conjugate pneumococcal vaccine in British Columbia: A retrospective cohort study

PLoS One. 2020 Sep 30;15(9):e0239848. doi: 10.1371/journal.pone.0239848. eCollection 2020.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • British Columbia / epidemiology
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Incidence
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Pneumococcal Infections / epidemiology*
  • Pneumococcal Infections / mortality
  • Pneumococcal Infections / prevention & control
  • Pneumococcal Vaccines / immunology*
  • Retrospective Studies
  • Serogroup
  • Streptococcus pneumoniae / classification
  • Streptococcus pneumoniae / immunology
  • Streptococcus pneumoniae / isolation & purification
  • Survival Rate
  • Young Adult

Substances

  • 13-valent pneumococcal vaccine
  • Pneumococcal Vaccines

Grants and funding

Invasive pneumococcal disease surveillance program is funded by British Columbia Ministry of Health. Population Data BC subsidized funding for the data that was required for NKV’s doctoral thesis project. The remainder of the data acquisition costs and salary for NKV was covered by an independent investigator grant from Pfizer, Canada to Dr. Marra. The funders had no role in the data analyses and interpretation.