immunnity

Definition immunnity

immunnity: immunnity n. the body's ability to resist infection, afforded by the presence of circulating *antibodies and white blood cells. Antibodies are manufactured specifically to deal with the antigens associated with different diseases as they are encountered. Active immunity arises when the body's own cells produce, and remain able to produce, appropriate antibodies following an attack of a disease or deliberate stimulation (see immunization). Passive immunity, which is only short-lived, is provided by injecting ready-made antibodies in *antiserum taken from another person or animal already immune. Babies have passive immunity, conferred by antibodies from the maternal blood and *colostrum, to common diseases for several weeks after birth.