Novel acellular vaccine for protection against Bordetella infection
Despite high vaccine coverage, whooping cough caused by Bordetella pertussis remains one of the most common vaccine-preventable diseases worldwide. Introduction of whole-cell pertussis (wP) vaccines in the 1940s and acellular pertussis (aP) vaccines in 1990s reduced mortality due to pertussis. Despite induction of both antibody and cell-mediated immune (CMI) responses by aP and wP vaccines, there has been resurgence of pertussis in many countries in recent years. Possible hypotheses for pertussis resurgence include (i) incompliance with the recommended vaccination programmes using the currently used aP vaccine and (ii) infection with resurged clinical isolates characterised by mutations in the virulence factors, resulting in antigenic divergence with vaccine strain, and increased production of pertussis toxin, resulting in dampening of immune responses. While use of these vaccines provide varying degrees of protection against whooping cough, protection against infection and transmission appears to be less effective, warranting continued efforts in the development of an improved pertussis vaccine.
Researchers at the Ohio State University have developed an acellular B. pertussus and B. bronchiseptica vaccine comprising the immunogenic BcfA (Bordetella colonization factor A) protein, which with remarkable efficacy establishes protective immunity in vivo against Bordetella infections. Proof of concept has been established in an in vivo mouse model. Both passive and active immunization have been shown to induce complete protection from bordetellosis, greatly decreased bacterial burden, high antibody titers and markedly reduced pulmonary injury.