A Hepatitis B surface antibody value greater than 10 mIU/mL is indicative of a positive test result and provides protection. However, if the level of antibody decreases later, turns negative, and all the hepatitis B virological indicators (i.e., both halves are negative), then it is necessary to revaccinate in order to produce hepatitis B surface antibody. In the case of self-cure of hepatitis B virus infection, the body can also obtain positive hepatitis B surface antibodies, the higher its titer, the stronger the resistance to hepatitis B virus infection. Hepatitis B surface antibody is a protective antibody of the human body, which is mainly produced by the surface antigen of hepatitis B virus through stimulating the immune system of the human body.