A significant increase in the incidence of
pertussis in adolescents and adults has been observed in vaccinated populations. Concomitantly, emergence of novel
pertussis toxin and
pertactin types in circulating Bordetella pertussis isolates was noticed. In this study, immunity induced by
acellular vaccines against
infection due to isolates expressing different
pertactin types and fimbriae was monitored in a mouse model. In accordance with previous studies, the effect of a bicomponent
DTPa vaccine on bacterial clearance was lower when compared with tri- or pentavalent
DTPa vaccines. Whatever the isolates used to infect mice, the tri- or pentavalent
DTPa vaccines were both efficacious in inducing immunity that resulted in clearance of
infection. These findings suggest that re-emergence of
pertussis might not be related to emergence of isolates escaping
vaccine protection. The present study reduces potential concerns about
acellular vaccine efficacy, but frequent monitoring of protection and surveillance of the evolution of the B.
pertussis population remains of particular importance.