IgG antibody to HAV usually persists for lifetime, conferring immunity to further hepatitis A infections. Because of the high cost of the vaccine
, some physicians prefer to test for hepatitis A antibody
to assess the need for vaccination. A test for total hepatitis antibody (IgG and IgM) should be ordered. If this test is positive and the person does not have any signs or symptoms of acute hepatitis, it can be assumed that they have protective levels of hepatitis IgG antibody.