Human Rabies Immune Globulin
Human rabies immune globulin (HRIG) is administered only once, at the beginning of anti-rabies prophylaxis, to previously unvaccinated persons. This will provide immediate antibodies until the body can respond to the vaccine by actively producing antibodies of its own. If possible, the full dose of HRIG should be thoroughly infiltrated in the area around and into the wounds. Any remaining volume should be injected intramuscularly at a site distant from vaccine administration.
HRIG should never be administered in the same syringe or in the same anatomical site as the first vaccine dose. However, subsequent doses of vaccine in the four-dose series can be administered in the same anatomic location where the HRIG dose was administered.
If HRIG was not administered when vaccination was begun, it can be administered up to seven days after the administration of the first dose of vaccine. Beyond the seventh day, HRIG is not recommended since an antibody response to the vaccine is presumed to have occurred.
Because HRIG can partially suppress active production of antibody, no more than the recommended dose should be administered. The recommended dose of HRIG is 20 IU/kg body weight. This formula is applicable to all age groups, including children.