Active immunisation is termed vaccination and elicits a response from the body that provides protective immunity. It is long-lasting.
Passive immunisation is, in practice, the injection of antibodies to provide short term protection.
MHC polymorphism enable the persistence of antigen, probably on follicular dendritic cells in lymphoid tissue, to elicit continued production of antibody from B cells. Whole organism vaccines tend to have these abilities. Subunit vaccines can be enhanced to produce these results by the use of adjuvants, such as alum. Vaccination should be deferred if there is an acute neurological condition Poliomyelitis Live, attenuated Oral. Killed parenteral vaccine also available.