Medical Term:
acquired immunity
Definition: resistance resulting from previous exposure of an individual in question to an infectious agent or antigen; it may be active and specific, as a result of naturally acquired (apparent or inapparent) infection or intentional vaccination (artificial active immunity); or it may be passive, being acquired through transfer of antibodies from another person or from an animal, either naturally, as from mother to fetus, or by intentional inoculation (artificial passive immunity).
