Hepatitis B Immunity Test - Hepatitis B Surface Antibody Test (HBsAb)

A quantitative or qualitative test to detect and measure the titer of antibodies directed against the hepatitis B virus surface antigen (Hepatitis B Surface Antibody - Anti-HBs or HBsAb) in serum. These antibodies are produced in response to hepatitis B vaccination or naturally after recovery from an acute infection. They provide immunity against future infection, and their presence in sufficient quantities (>10 mIU/mL) is considered an indicator of protective immunity.