The effect of pertussis whole cell and acellular vaccines on pulmonary immunology in an aerosol challenge model

Recent clinical trials have shown that the new generation of acellular pertussis vaccines (Pa) can confer protection against whooping cough with negligible adverse reactions. We have compared the effects of pertussis whole cell and acellular vaccines on pulmonary immune responses after aerosol challenge in a murine model of infection. Mice were vaccinated with PBS, Pw or Pa and challenged with Bordetella pertussis by the aerosol route. Cytokine gene expression was analysed from lung tissue and cells; lung lymphocytes were re-stimulated in vitro and cytokines produced measured. The results obtained are consistent with the proposal that a strong Th-1 response is associated with bacterial clearance in both the non-vaccinated and Pw vaccinated mice. The acellular vaccine treated mice cleared the bacterial challenge (with an intermediate efficacy) in the presence of low levels of any of the cytokines assessed. This suggests that Pa protects via a Th-2 independent mechanism.