Table 2.

Case Definitions in the Ancillary Efficacy Analyses

Three primary case definitions I)  Cough ≥7 days duration and a positive culture or PCR for Bordetella pertussis, or a significant ELISA IgG or IgA antibody response to any B pertussis antigen, or a significant agglutinin response, and no isolation of Bordetella parapertussis.
II)  Cough ≥21 days duration with presence of paroxysmal cough, whoop, or posttussive vomiting (modified WHO clinical criteria), or central investigator's clinical diagnosis of definite or probable pertussis.
III)  Definition II above or the primary case definition in the principal efficacy analysis (Table 1).
Four secondary case definitions I)  Cough ≥7 days duration and a positive culture or PCR for B pertussis, or a significant ELISA IgG or IgA antibody response to any B pertussis antigen, or a significant agglutinin response, and no isolation of B parapertussis.
II)  Cough ≥21 days duration with presence of paroxysmal cough, whoop, or posttussive vomiting (modified WHO clinical criteria) and a positive culture or PCR for B pertussis, or a significant ELISA IgG or IgA antibody response to PT with or without a response to other B pertussis antigens, and no isolation of B parapertussis.
III)  Cough ≥21 days duration with presence of paroxysmal cough, whoop, or posttussive vomiting (modified WHO clinical criteria), and a positive culture or PCR for B pertussis, or a significant ELISA IgG or IgA antibody response to any B pertussis antigen, or a significant agglutinin response, and no isolation of B parapertussis.
IV)  Any cough illness.
Two noncase definitions for an exposed study child I)  No cough or mild respiratory illness (coryza or cough <7 days duration).
II)  No respiratory illness at all.
  • Abbreviations: PCR, polymerase chain reaction; ELISA, enzyme-linked immunosorbent assay; IgG, immunoglobulin G; IgA, immunoglobulin A; WHO, World Health Organization; PT, pertussis toxin.