Evaluating principal surrogate markers in vaccine trials in the presence of multiphase sampling.

ABSTRACT: This article focuses on the evaluation of vaccine-induced immune responses as principal surrogate markers for predicting a given vaccine's effect on the clinical endpoint of interest. To address the problem of missing potential outcomes under the principal surrogate framework, we can utilize baseline predictors of the immune biomarker(s) or vaccinate uninfected placebo recipients at the end of the trial and measure their immune biomarkers. Examples of good baseline predictors are baseline immune responses when subjects enrolled in the trial have been previously exposed to the same antigen, as in our motivating application of the Zostavax Efficacy and Safety Trial (ZEST). However, laboratory assays of these baseline predictors are expensive and therefore their subsampling among participants

SUBMITTER: Huang Y 

PROVIDER: S-EPMC5743779 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature