an antiviral treatment and immunomodulator used to treat active infections or regulate immune functioning in those with immune deficiencies or autoimmune disorders. IVIG contains antibodies (IgG immunoglobulins) that target pathogens found in the bloodstream for destruction.
The gamma globulins are pooled from the blood products of many blood donors that have been treated to kill any infections present. Gamma globulin therapy is FDA approved to treated several diseases but is used off-label in a many others including many auto-immune ones.
Gamma globulins downsides include high expense and low availability although both have improved somewhat recently. It can be administered intramuscularly or intravenously.