Editing Immunization (section)

===Passive immunization===
{{Main|Passive immunity}}
Passive immunization is where pre-synthesized elements of the immune system are transferred to a person so that the body does not need to produce these elements itself. Currently, [[antibodies]] can be used for passive immunization. This method of immunization begins to work very quickly, but it is short lasting, because the antibodies are naturally broken down, and if there are no B cells to produce more antibodies, they will disappear.

Passive immunization occurs physiologically, when antibodies are transferred from mother to [[fetus]] during [[pregnancy]], to protect the fetus before and shortly after birth.

Artificial passive immunization is normally administered by [[Injection (medicine)|injection]] and is used if there has been a recent outbreak of a particular disease or as an emergency treatment for toxicity, as in for [[tetanus]]. The antibodies can be produced in animals, called "serum therapy," although there is a high chance of [[anaphylactic shock]] because of immunity against animal serum itself. Thus, [[humanized antibodies]] produced ''[[in vitro]]'' by [[cell culture]] are used instead if available.