Vaccination

Vaccination, method of inducing immunity to infectious disease due to bacteria or virus. Early methods of inducing immunity consisted of the deliberate innoculation of material from a mild case. The vaccinated body forms antibodies and is able to produce large quantities of them rapidly thereafter. This gives protection equivalent to that induced by an attack of the disease. It is occasionally followed by a reaction resembling a mild form of the disease, rarely by the serious manifestations. Persons on steroids, with immunity disorders, or eczema may suffer severe reactions and should generally not receive vaccinations.

See also: Immunity.