Injectable tetanus toxoid is an example of: September 2006

Ans. B: Active immunity Passive immunity: Immunity produced by the transfer to one person of antibodies that were produced by another person. Protection from passive immunity diminishes in a relatively sho time, usually a few weeks or months. For example, antibodies passed from the mother to the baby before bih confer passive immunity to the baby for the first 4-6 months of life. Passive immunity may be induced by: By administration of an antibody containing preparation (Immunoglobulin or antisera) By transfer of maternal antibodies across the placenta Active immunity: The production of antibodies against a specific agent by the immune system. Active immunity can be acquired in two ways: By contracting an infectious disease -- such as, for example, chickenpox; or By receiving a vaccination which may be a killed vaccine, a live attenuated vaccine or toxoid Active immunity is permanent. The individual is protected from the disease all their life