A positive hepatitis B surface antibody result above the standard value indicates that there is immunity to the hepatitis B virus in the body, which protects the body from being infected by the hepatitis B virus. Hepatitis B surface antibody is a kind of protective antibody. A positive result over the standard value indicates that the protective antibody in the body can prevent the body from being infected by the hepatitis B virus. This may be due to the hepatitis B vaccine, or high hepatitis B antigen caused by recovery from a previous hepatitis B virus infection. Usually, when there are high levels of hepatitis B antibodies in the body, the antibodies will react to help protect against the hepatitis B virus if the person is exposed to it. The higher the antibodies the more protective they are and the longer they last. However, these antibodies are not constant, and antibody titers can gradually decrease over time. Therefore, it is necessary to monitor the antibody titer regularly, and if it disappears, the hepatitis B vaccine can be reinforced with another injection.