Pertussis vaccines and protective immunity

Despite high vaccine coverage, reported cases of pertussis have increased steadily over the last twenty years. This resurgence has stimulated interest in host responses to pertussis infection and vaccination with the goal of developing more effective next-generation vaccines and vaccination strategies. Optimal protection against Bordetella pertussis appears to be multifactorial requiring both humoral and cellular responses. Natural infection and whole-cell pertussis vaccination induce Th1 and Th17-dominated responses. In contrast, acellular vaccines induce Th2-dominated responses. Available immunological data indicate that while antibodies provide protection against disease, Th1 and Th17-mediated immune responses are required for bacterial clearance and long-lasting protection. The nature of the priming in children appears to be important in modulating bias and durability of immune responses required to provide protection against B. pertussis. This review summarizes the current understanding of differences in immune responses and their role in protection against B. pertussis following infection or vaccination.