Immunologic hazards associated with vaccination of humans.

Universal vaccination remains the most effective measure for preventing the spread of many infectious diseases. Since vaccination is one of the few medical interventions applied to healthy individuals, its safety must be as absolute as human efforts can make it. Questions have been raised recently about the possibility that particular vaccines can trigger or promote autoimmune disease, although controlled, population-based studies have not supported this notion. In collaboration with the World Health Organization, we investigated a subunit vaccine of human chorionic gonadotropin, and found evidence of benign, but not pathologic, autoimmunity. We propose an algorithm for systematic study of possible immunologic hazards of vaccines in animals and human subjects.