Rabies immunoglobulin (RIG) is a medication made up of antibodies against the rabies virus.^[10] It is used to prevent rabies following exposure.^[10] It is given after the wound is cleaned with soap and water or povidone-iodine and is followed by a course of rabies vaccine.^[10] It is given by injection into the site of the wound and into a muscle.^[10] It is not needed in people who have been previously vaccinated against rabies.^[11]

Common side effects include pain at the site of injection, fever, and headache.^[10] Severe allergic reactions such as anaphylaxis may rarely occur.^[12] Use during pregnancy is not known to harm the baby.^[10] It works by binding to the rabies virus before it can enter nerve tissue.^[10] After the virus has entered the central nervous system, rabies immunoglobulin is no longer useful.^[10]

The use of rabies immunoglobulin in the form of blood serum dates from 1891.^[13] Use became common within medicine in the 1950s.^[14] It is on the World Health Organization's List of Essential Medicines.^[15] Rabies immunoglobulin is expensive and hard to come by in the developing world.^[16] In the United States it is estimated to be more than US$1,000.00 per dose.^[17] It is made from the blood plasma of people or horses who have high levels of the antibody in their blood.^[10][17] The horse version is less expensive but has a higher rate of side effects.^[17][14]

Rabies immunoglobulin (RIG) is indicated for the passive, transient post-exposure prophylaxis of rabies infection, when given immediately after contact with a rabid or possibly rabid animal and in combination with a rabies vaccine.^[18][19][1]