Immunoglobulins, or antibodies, are an important part of the body's defense system – the immune system. The major class of immunoglobulins, immunoglobulin G (IgG), is made up of antibodies that protect the body against many bacterial and some viral infections. People with PI often cannot produce enough of these protective antibodies.

GAMMAGARD LIQUID is a highly purified preparation of IgG that can help people with PI by replacing their IgG antibodies, helping the immune system function properly.