Abstract

Streptococcus pneumoniae is a major causative agent of adult pneumonia. Following the introduction of pneumococcal conjugate vaccines (PCV) for children, serotype replacement has been reported in adult invasive pneumococcal diseases, but it has not been well-studied for adult pneumococcal pneumonia cases in Asia. To investigate serotype replacement in adult pneumococcal pneumonia in Japan, we conducted a systematic literature search across five databases using terms including pneumococcus, serotype, and their synonyms and derivatives. After the assessment of the identified articles, data on the pneumococcal serotype distribution among adult pneumonia cases were extracted from relevant studies. Twenty-two studies were reviewed, and four relevant articles were included in the pooled data analysis. There was a significant decrease in the proportion of the 7-valent PCV (PCV7)-covered serotypes from before and after the introduction of PCV7 for children (-18.1%, p<0001); moreover, there were significant increases in the proportions of serotypes covered by PCV13 but not by PCV7 (+9.9%, p=0.003) and serotypes covered by the 23-valent polysaccharide vaccine but not by PCV7 (+9.4%, p=0.007). Serotype replacement occurred in adult pneumococcal pneumonia cases following the vaccination of children with PCV7 in Japan. Further nationwide surveillance is warranted to investigate serotype replacement in the post-PCV13 phase.

  • Western Pacific
  • Japan
  • Adults
  • Administration
  • Efficacy/effectiveness
  • Pneumococcal disease