Prospects for a new acellular pertussis vaccine.

A number of virulence factors of Bordetella pertussis have been isolated and studied for their roles in pathogenesis and are under consideration, singly and in combinations, for inclusion in candidate acellular pertussis vaccines to be used in clinical trials to demonstrate safety and efficacy. Prospective immunogens would include lymphocytosis-promoting factor, agglutinogens, adenylate cyclase, filamentous haemagglutinin, heat-labile toxin and tracheal cytotoxin. Some of these factors are toxins and would need to be properly toxoided before being formulated into a vaccine. Clinical trials with acellular pertussis vaccines are planned or in progress in several countries.