Passive Immunity Index to this page Active vs.
Active immunity is the development of antibodies in response to stimulation by an antigen .
Once formed, those antibodies can be removed from the host and transferred into another recipient where they provide immediate passive immunity. The protection is short-lived, lasting only until the last of the injected antibodies have been catabolized . Horse proteins are foreign to the human patient and will, in due course, elicit an active immune response. This may lead to an allergic reaction such as systemic anaphylaxis or serum sickness To avoid such problems, humans are often used as the source of passive antibodies. Instead it is the C-region portion of the antibody molecules that provides the protection.