Test Details: Hepatitis B is a viral infection that causes inflammation of the liver. HBV is spread through contact with body fluids. Common forms of exposure to HBV often occur during childbirth and infancy, when sharing needles for intravenous drug use, or during unprotected sex. Hepatitis B testing looks for antigens, antibodies, or the genetic material of HBV. Anti-HBs or HBsAb (Hepatitis B surface antibody) - A "positive" or "reactive" anti-HBs (or HBsAb) test result indicates that a person is protected against the hepatitis B virus. This protection can be the result of receiving the hepatitis B vaccine or successfully recovering from a past hepatitis B infection.