Intravenous immunoglobulin (IVIG) is a type of medicine made from donated blood plasma. IVIG is made of certain antibodies that fight bacteria, fungi, viruses, or other substances that can cause disease.

Some types of IVIG can be used to reduce the risk of infection in people who have too few antibodies to effectively fight infections because of a weakened immune system. Other types can be used to prevent infection in people who may have been exposed to a disease-causing virus, such as the hepatitis A virus. IVIG can also be used as treatment for immune system problems that were present at birth (congenital immunodeficiency). And IVIG can be used to prevent problems that Rh incompatibility can cause in a fetus.

Because immunoglobulin is made from donated blood, it is sometimes in short supply. It is also very expensive.