An immune globulin injection is the administration of antibodies that provide protection against certain diseases. Unlike a vaccine, which stimulates the body to produce its own antibodies, an immune globulin injection provides prefabricated antibodies that have been filtered from other people’s bodies. An immune globulin injection is useful if you don’t have the two or three weeks of time needed to wait for a vaccine to become effective. For example, if you are suddenly traveling overseas to a country where you might be exposed to the hepatitis A virus, you need protection immediately and don’t have time to wait for the vaccine to work.
The major drawback to an immune globulin injection is that the protection will fade as the antibodies are slowly destroyed over three to four months. For this reason, an immune globulin injection is often given at the same time as a vaccine. A common example is giving both the rabies immune globulin injection and the rabies vaccine when someone is exposed to a rabid animal. The antibodies in the immune globulin injection will work immediately to protect the recipient from the disease, while the vaccine will stimulate the long-term production of the body’s own antibodies.