Pertussis vaccine controversies and acellular pertussis vaccine.

Pertussis still continues to cause significant morbidity and mortality worldwide. Because of the high reactogenicity of whole cell pertussis vaccine, it had evoked public controversy in several countries. In 1970 Japan abandoned use of whole cell pertussis vaccine and mounted efforts to develop better vaccine. To date, nearly 24 acellular pertussis vaccines have been developed, using different number and quantity of components. No acellular vaccine is most or least immunogenic with respect to all included antigens. Vaccine efficacy and duration of immunity is comparable with whole cell pertussis vaccine. The adverse events are two thirds less compared to whole cell vaccine.