immunization

Definition immunization

immunization: immunization n. the production of *immunity by artificial means. Passive immunity, which is temporary, may be conferred by the injection of an *antiserum, but the production of active immunity calls for the use of treated antigens, to stimulate the body to produce its own antibodies: this is the procedure of *vaccination (also called inoculation). The material used for immunization (the *vaccine) may consist of live bacteria or viruses so treated that they are harmless while remaining antigenic or completely dead organisms or their products (e.g. toxins) chemically or physically altered to produce the same effect.