O-antigen enables Bordetella parapertussis to avoid Bordetella pertussis-Induced Immunity
Infection and Immunity 75: 4972-4979.
Bordetella pertussis and B. parapertussis are closely-related endemic human pathogens which cause whooping cough, a disease that is re-emerging in human populations. Despite how closely-related these pathogens are, their co-existence, and the limited efficacy of B. pertussis vaccines against B. parapertussis, suggests a lack of cross-protective immunity between the two. We sought to address the ability of infection-induced immunity against one of these pathogens to protect against subsequent infection by the other using a mouse model of infection. Immunity induced by B. parapertussis infection protected against subsequent infections by either species. However, immunity induced by B. pertussis infection prevented subsequent B. pertussis infections but did not protect against B. parapertussis infections. The O-antigen of B. parapertussis inhibited binding of antibodies to the bacterial surface and was required for B. parapertussis to colonize B. pertussis-convalescent mice. Thus, the O-antigen of B. parapertussis confers asymmetrical cross-immunity between the causative agents of whooping cough. We propose that these findings warrant investigation of the relative role of B. parapertussis in the resurgence of whooping cough.