Efficacy of polysaccharide pneumococcal vaccine in adults in more developed countries: the state of the evidence

Lancet Infect Dis. 2003 Feb;3(2):71-8. doi: 10.1016/s1473-3099(03)00514-0.


We review studies on the efficacy against disease caused by Streptococcus pneumoniae of the 23-valent polysaccharide pneumococcal vaccine in adult populations in the more developed countries. Meta-analyses of primary vaccine trials have attempted to reduce uncertainty from lack of power. Vaccine efficacy calculated from studies in South African gold-miners and in Papua New Guinea, with high attack rates and differing serotype patterns, cannot automatically be applied to more developed countries. Meta-analyses will overestimate a protective effect if this clinical heterogeneity is ignored. Meta-analyses limited to trials in the more developed setting show no protective effect against pneumococcal pneumonia and a non-significant protective effect against bacteraemia. Lack of a specific diagnosis limits the ability to detect a protective effect against pneumococcal pneumonia. Most, but not all, observational studies confirm a protective effect against bacteraemia. An effect on mortality in more developed countries has yet to be documented.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adult
  • Aged
  • Bacteremia / prevention & control
  • Developed Countries*
  • Humans
  • Meta-Analysis as Topic
  • Middle Aged
  • Pneumococcal Infections / epidemiology
  • Pneumococcal Infections / prevention & control*
  • Pneumococcal Vaccines*
  • Pneumonia, Pneumococcal / prevention & control
  • Randomized Controlled Trials as Topic


  • Pneumococcal Vaccines