Use of an individual-based model of pneumococcal carriage for planning a randomized trial of a whole-cell vaccine.

ABSTRACT: For encapsulated bacteria such as Streptococcus pneumoniae, asymptomatic carriage is more common and longer in duration than disease, and hence is often a more convenient endpoint for clinical trials of vaccines against these bacteria. However, using a carriage endpoint entails specific challenges. Carriage is almost always measured as prevalence, whereas the vaccine may act by reducing incidence or duration. Thus, to determine sample size requirements, its impact on prevalence must first be estimated. The relationship between incidence and prevalence (or duration and prevalence) is convex, saturating at 100% prevalence. For this reason, the proportional effect of a vaccine on prevalence is typically less than its proportional effect on incidence or duration. This relationship is further c

SUBMITTER: Cai FY 

PROVIDER: S-EPMC6181404 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature