Due to local and systemic side-effects, the currently used, highly effective, whole-cell
pertussis vaccines (WCVs) will be replaced by
acellular vaccines (ACVs) in some countries. These ACVs contain detoxified
pertussis toxin, either alone or in combination with the filamentous haemagglutinin,
pertactin and fimbriae. Ongoing clinical trials show that ACVs are clearly less reactogenic than WCVs and that ACVs comprised of three to five
proteins are highly efficacious in inducing protection against Bordetella pertussis
infections. An important unresolved question is, what the effect will be of the switch from WCVs to ACVs on the incidence of Bordetella parapertussis
infections, the second causative agent of
pertussis. A comparison of the efficacy of WCVs and ACVs against B. parapertussis
infection is required to answer this question. We show that the Dutch WCV, although prepared from B.
pertussis strains, protects against B. parapertussis
infection in a murine respiratory model, although less efficiently than against B.
pertussis infection. It was shown previously that the ACV components
pertussis toxin, FHA and
pertactin did not protect against B. parapertussis
infection in a murine respiratory model. We have investigated the efficacy of two other ACV components, B.
pertussis serotype-2 and -3 fimbriae against B. parapertussis
infection in the murine model. The B.
pertussis fimbriae protected mice against B. parapertussis
infection although less efficiently than against B.
pertussis infection. This result indicates that B.
pertussis and B. parapertussis fimbriae are antigenically distinct. B.
pertussis fimbriae were found to be as efficacious as the WCV against B.
pertussis infection. Our results are discussed in the light of the switch from WCVs to ACVs.