''Passive immunity'' is acquired through [[transfer]] of antibodies or activated T-cells from an immune host, and is short lived -- usually lasting only a few months ''Active immunity'' is induced in the [[host]] itself by antigen, and lasts much longer, sometimes life-long.[http://en.wikipedia.org/wiki/Immunity_%28medical%29] | ''Passive immunity'' is acquired through [[transfer]] of antibodies or activated T-cells from an immune host, and is short lived -- usually lasting only a few months ''Active immunity'' is induced in the [[host]] itself by antigen, and lasts much longer, sometimes life-long.[http://en.wikipedia.org/wiki/Immunity_%28medical%29] |