Impact of infant 13-valent pneumococcal conjugate vaccine on serotypes in adult pneumonia

Infant 13-valent pneumococcal conjugate vaccination (PCV13) was introduced to the UK in 2010. Its impact on serotypes implicated in adult non-bacteraemic pneumococcal pneumonia is not known. Beginning in 2008, a 5-year prospective cohort study of adults admitted to hospital with community-acquired pneumonia (CAP) was conducted. Pneumococcal serotype was established using a validated multiplex immunoassay (Bio-Plex; Bio-Rad, Hercules, CA, USA). The overall incidence for hospitalised CAP and pneumococcal CAP was 79.9 (95% CI 76.6-83.3) and 23.4 (95% CI 21.6-25.3) per 100,000 population, respectively. A decline in CAP (incidence rate ratio (IRR) per year 0.96, 95% CI 0.94-0.99; p=0.016) and pneumococcal CAP (IRR per year 0.84, 95% CI 0.80-0.89; p