Intravenous immunoglobulin consists of the antibodies extracted from pooled blood donations from hundreds of donors, which are likely to include a broad range of antibodies against many different pathogens. This therapy is different from passive immunotherapy where plasma with high levels of specifically anti-HIV antibodies is given.

Intravenous immunoglobulin is marketed commercially under the tradenames Endobulin, Gamimune-N, Sandoglobulin, Venoglobulin , Vigam and WinRho SD. It is sometimes abbreviated to IVIG, or referred to as gamma globulin.

Intravenous immunoglobulin is a licensed treatment for people with low antibody levels, for idiopathic thrombocytopenia purpura and for preventing infections in people who have received blood transfusions. It is also the standard treatment for B19 parvovirus infection. In March 1994, it was licensed as a treatment for HIV-positive children. Its use as an anti-HIV treatment in adults is experimental and unlicensed.

Studies in HIV-positive children confirm that treatment with intravenous immunoglobulin can help to prevent bacterial and viral infections, but only in children with CD4 cell counts above 200 cells/mm³ or who were not receiving co-trimoxazole (Septrin) prophylaxis. For children with lower CD4 cell counts, it does not appear to offer any added protection against infections or to prolong survival^[1][2]. However, it did not affect CD4 cell counts^[3].

Studies in adults have also shown no evidence of beneficial effects on immunological markers or CD4 cell count, although the injections did decrease the frequency of infection^[4][5]. One study suggested that it might be an effective treatment for low platelet counts due to HIV^[6].

Despite its name, the drug can be given either by the intravenous or the intramuscular injection route. Side-effects of immunoglobulin are rare but may include flushing of the face, chest tightness, chills and fever.