Nationwide population-based surveillance of invasive pneumococcal disease in Japanese children: Effects of the seven-valent pneumococcal conjugate vaccine

Vaccine. 2015 Nov 9;33(45):6054-60. doi: 10.1016/j.vaccine.2015.07.069. Epub 2015 Jul 31.

Abstract

Background: In Japan, the seven-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2010. PCV13 has replaced PCV7 since November 2013.

Methods: The effectiveness of PCV7 in protecting against invasive pneumococcal disease (IPD) in children aged <5 years was evaluated in a nationwide active population-based surveillance of IPD in 2008-2013 in 10 prefectures in Japan.

Results: 1181 cases were identified; 711 pneumococcal strains were analyzed for serotyping and antimicrobial resistance. Compared with the baseline IPD incidence (25.0 per 100,000), a 98% decline in IPD caused by PCV7 serotypes was found after the introduction of PCV7. This was partially offset by an increased incidence of IPD caused by PCV13 minus PCV7 and non-PCV13 serotypes, resulting in a 57% decline in overall IPD incidence. Absolute increases in the incidence rates of IPD caused by PCV13 minus PCV7 and non-PCV13 serotypes were 2.1 and 2.8 per 100,000 during the study period, respectively. The proportion of meropenem-nonsusceptible strains, especially with serotypes 19A and 15A, increased significantly after PCV7 introduction.

Conclusions: Our data confirmed a 98% decline in IPD incidence caused by PCV7 serotypes in children aged <5 years and serotype replacement after PCV7 introduction. This shows the importance of continuing surveillance of serotypes responsible for IPD and their antimicrobial resistance in Japan.

Keywords: Children; Invasive pneumococcal disease; Japan; Meropenem; Serotype replacement; Seven-valent pneumococcal conjugate vaccine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Anti-Bacterial Agents / pharmacology
  • Child
  • Child, Preschool
  • Drug Resistance, Multiple, Bacterial
  • Female
  • Heptavalent Pneumococcal Conjugate Vaccine / immunology*
  • Humans
  • Infant
  • Japan / epidemiology
  • Male
  • Meropenem
  • Microbial Sensitivity Tests
  • Pneumococcal Infections / ethnology
  • Pneumococcal Infections / microbiology*
  • Pneumococcal Infections / mortality
  • Pneumococcal Infections / prevention & control*
  • Population Surveillance
  • Prospective Studies
  • Serogroup
  • Streptococcus pneumoniae / classification*
  • Streptococcus pneumoniae / drug effects*
  • Streptococcus pneumoniae / pathogenicity
  • Thienamycins / pharmacology

Substances

  • Anti-Bacterial Agents
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Thienamycins
  • Meropenem