Citation

The reemergence of pertussis or whooping cough in several countries highlights the need for better vaccines. Acellular pertussis vaccines (aPV) contain alum as the adjuvant and elicit Th2 biased immune responses that are less effective in protecting against infection than the reactogenic whole cell pertussis vaccines (wPV), which elicit primarily a Th1/Th17 response. An important goal for the field is to devise aPVs that will induce immune responses similar to wPV. We show that Bordetella Colonization Factor A (BcfA), an outer membrane protein fromB. bronchiseptica,has strong adjuvant function and elicits cellular and humoral immune responses to heterologous andB. pertussisantigens. Addition of BcfA to a commercial aPV resulted in greater reduction ofB. pertussisnumbers from the lungs than elicited by aPV alone. More efficient pathogen clearance was accompanied by increased IL-17 and reduced IL-5, and an increased ratio of IgG2/IgG1 antibodies. Thus our results suggest that BcfA improves aPV induced responses by modifying the alum-induced Th2-biased aPV response towards Th1/Th17. A re-designed aPV containing BcfA may allow better control of pertussis reemergence by reshaping immune responses to resemble those elicited by wPV immunization. Copyright 2018 American Society for Microbiology.