The HBsAb test, or hepatitis B surface antibody test, looks for antibodies that your immune system makes in response to the surface protein of the hepatitis B virus. The hepatitis B surface antibody is also referred to as anti-HBs and should not be confused with HBsAg, which stands for hepatitis B surface antigen.
This HBsAb test may be done to look for prior exposure to Hepatitis B or whether your vaccination was successful.
When HBsAb is positive (antibodies are present,) it usually means that you have recovered from a hepatitis B infection and have some immunity. If your HBsAb test is negative, it means you are not immune to the Hepatitis B virus. If your other Hepatitis B tests (both HBsAb and other hepatitis tests) are negative, it means you are either not infected or that you are in the very early incubation stage of infection.
