Binding of murine antibodies against whole-cell pertussis vaccine or filamentous haemagglutinin by Bordetella pertussis from patients with whooping cough

In 1996 an unexpected rise in the incidence of whooping cough occurred in t he Netherlands, and antigenic divergence between vaccine strains and clinic al isolates has been suggested as a cause for this phenomenon. To investiga te this assumption, the binding of murine antibodies against the whole-cell pertussis vaccine or filamentous haemagglutinin, an important protective a ntigen, to a limited number of Bordetella pertussis strains isolated during different time-periods (1991-92, 1994 and 1996) was assessed. The results showed that all strains were recognized equally well by these antisera, ind icating that filamentous haemagglutinin was unchanged during the time-perio ds examined. Although over the years changes have occurred in at least two surface proteins of B. pertussis, these changes are too subtle to be recogn ized by the antibodies raised in mice. Further research is required to asse ss whether antigenic variation of B. pertussis has an effect on protective immunity.