Nasal vaccines for pertussis

Abstract

Whooping cough, caused by Bordetella pertussis, is still a major cause of morbidity and mortality worldwide. Current acellular pertussis (aP) vaccines induce potent circulating IgG and prevent severe disease in children/adults and in infants born to vaccinated mothers. However, they do not prevent nasal infection, allowing asymptomatic transmission of B. pertussis. Studies in animal models have demonstrated that, unlike natural infection, immunization with aP vaccines fails to induce secretory immunoglobulin A (IgA) or interleukin-17 (IL-17)-secreting tissue-resident memory CD4 T (T_RM) cells, required for sustained sterilizing immunity in the nasal mucosa. Live-attenuated vaccines or aP vaccines formulated with novel adjuvants that induce respiratory IgA and T_RM cells, especially when delivered by the nasal route, are in development and have considerable promise as next-generation vaccines against pertussis.