Pertussis vaccines: present status.

The eradication of pertussis as a worldwide disease is unforeseeable for the present and immediate future. Mortality and morbidity from clinical pertussis are still commonly reported, especially in underdeveloped countries where mass immunization programs are virtually nonexistent. To achieve control of the disease, a high level of immunization coverage is necessary, and pertussis WCPV still remains one of the most effective bacterial vaccines. But, primarily because of its reactogenicity for infants, much effort has been directed toward the characterization of bacterial components important in pathogenesis and for the development of acellular vaccines. Progress in the last decade has resulted in the production and use of such vaccines for routine vaccination, and their use in Japan, as well as the recent clinical trials in Sweden and several phase I/II studies in other countries, has shown that these preparations are safer than conventional WCPV, and equally effective, in preventing disease. The development of future acellular pertussis vaccines by gene manipulation may finally inspire public confidence for vaccine prophylaxis, eventually leading to eradication of the disease. However, the production and use of such sophisticated vaccines is dependent on many factors, and consequently conventional WCPV may still be used in many countries for several years to come.