Table 1.

Case Definitions in the Principal Efficacy Analysis

Primary caseCough ≥7 days duration and a positive culture or PCR for Bordetella pertussis, or a significant enzyme-linked immunosorbent assay immunoglobulin G or immunoglobulin A antibody response to pertussin toxin with or without a response to other B pertussis antigens, and no isolation ofB parapertussis.
Secondary caseSame as primary case definition.
Noncase in an exposed study childA study child not meeting the clinical or laboratory criteria of a secondary case.