The pertussis vaccine controversy.

Over the past few years, there has been continuing controversy about whether the benefits of routine vaccination for pertussis outweight the potential risks. Some of the epidemiologic and technical issues include ascertainment and reporting of cases, case definition and laboratory confirmation, identification and purification of antigens, vaccine potency measurement, vaccine efficacy, and vaccine safety. Other factors include legal and economic issues, ethical concerns, emotional overlays, and the role of the media. Much of the evidence for the benefits of pertussis vaccination arises from epidemiologic studies regarding the incidence of the disease and the effectiveness of the vaccine in preventing it. The very nature of epidemiologic data has contributed to the controversy, since there is virtually no epidemiologic study with absolutely incontrovertible results that allow only one interpretation. Nonetheless, available evidence indicates that the benefits of pertussis vaccination far outweight the risks.