Passive immunity

A state of passive immunity is established of immunity from immunized to non-immune host by administration of serum antibodies, or transplantation of lymphocytes. The state is normally short-lived, and is part of therapy for active disease.

The most common reason for inducing passive immunity is to counteract the effects of a circulating biological toxin, which may be of bacterial origin, or from a higher-level organism, such as a venomous snake. Antitoxin is a routine part of treatment for botulism and tetanus.