The HBsAb (Hepatitis B Surface Antibody), also known as Anti-HBs, is a blood test that detects the presence of antibodies against the Hepatitis B surface antigen (HBsAg). These antibodies are produced by the immune system either in response to a past Hepatitis B infection or following Hepatitis B vaccination.
This test is used to determine whether a person has developed immunity to the Hepatitis B virus — either through vaccination or natural infection and recovery. It is commonly ordered to confirm the effectiveness of Hepatitis B vaccination, screen healthcare workers and high-risk individuals for immunity, and as part of a complete Hepatitis B panel to determine the stage of infection or recovery. A positive (reactive) result indicates protection against Hepatitis B.
