title: Estimation of vaccine efficacy against acquisition of pneumococcal carriage.
abstract: 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.
authors.affiliation: Department of Vaccination and Immune Protection, National Institute for Health and Welfare (THL), Finland. hanna.rinta-kokko@thl.fi
authors.forename: Hanna
authors.initials: H
authors.lastname: Rinta-Kokko
authors.forename: Ron
authors.initials: R
authors.lastname: Dagan
authors.forename: Noga
authors.initials: N
authors.lastname: Givon-Lavi
authors.forename: Kari
authors.initials: K
authors.lastname: Auranen
mesh_terms: D002353:Carrier State / Q000382:microbiology* / Q000517:prevention & control*; D003430:Cross-Sectional Studies; D006801:Humans; D009305:Nasopharynx / Q000382:microbiology; D022242:Pneumococcal Vaccines / Q000276:immunology*; D015995:Prevalence; D013290:Streptococcal Infections / Q000382:microbiology* / Q000517:prevention & control*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*
chemical_list: D022242:Pneumococcal Vaccines