F2 and pertussis: Hall et al. demonstrated that the SmithKline Beecham three-component aP vaccine (detoxified PT [PTd], FHA, and a 69-kDa antigen, presumably pertactin [PRN]), the Connaught five-component vaccine (PTd, FHA, agglutinins 2+3 [fimbriae], and PRN), and Evans whole-cell pertussis vaccine protected against cough upon intrabronchial B. pertussis challenge (41).