Mechanisms of natural and vaccine-induced immunity to Bordetella pertussis.

Bordetella pertussis causes whooping cough (pertussis), a respiratory infectious disease that is resurgent despite high vaccine coverage. Research on the mechanisms of immunity to B. pertussis have demonstrated protective roles for innate immune cells, antibodies and T cells in immunity induced by natural infection. Studies in animal models have demonstrated that IL-17-secreting respiratory tissue-resident memory CD4+ T (TRM) cells and associated recruitment of neutrophils play a critical role in clearance of bacteria from nasal mucosa. However, current acellular pertussis (aP) vaccines, while inducing potent serum antibody responses and protecting against pertussis disease, fail to induce local immune responses in the respiratory tract, thus allowing transmission of the bacteria from vaccinated individuals. Motivated by the resurgence of pertussis and the limitations of the current aP vaccines, several research groups involved in the design of more effective third generation pertussis vaccines are focusing on nasal-delivery approaches that induce respiratory TRM cells and mucosal IgA, as well as circulating antibodies.