Estimation of vaccine efficacy against acquisition of pneumococcal carriage

Vaccine. 2009 Jun 12;27(29):3831-7. doi: 10.1016/j.vaccine.2009.04.009. Epub 2009 Apr 23.


Evaluation of the effect of new conjugate vaccines on nasopharyngeal carriage of Streptococcus pneumoniae (pneumococcus) has been based on simple comparisons of the prevalence of carriage in vaccinees and controls. However, the definition and measurement of vaccine efficacy should be based on knowledge of the actual mechanism of the vaccine's effect. According to current knowledge, conjugate vaccines affect acquisition. We propose a simple-to-use method to measure vaccine efficacy against serotype-specific acquisition that needs only cross-sectional measurements of carriage. We demonstrate the use of the method by application to a data set where it is also possible to estimate efficacy against acquisition from longitudinal measurements.

Publication types

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

MeSH terms

  • Carrier State / microbiology*
  • Carrier State / prevention & control*
  • Cross-Sectional Studies
  • Humans
  • Nasopharynx / microbiology
  • Pneumococcal Vaccines / immunology*
  • Prevalence
  • Streptococcal Infections / microbiology*
  • Streptococcal Infections / prevention & control*
  • Streptococcus pneumoniae / isolation & purification*


  • Pneumococcal Vaccines