Positive anti-hepatitis B virus surface antigen antibody refers to a positive surface antibody to the hepatitis B virus. There is some repetition of these terms in the question, for example, the first anti word is repeated with the anti in the antibody that follows, so it refers to the hepatitis B surface antibody. This is a protective antibody that is checked in the five tests for hepatitis B. This antibody becomes positive, usually obtained through the hepatitis B vaccination. After three complete injections of the hepatitis B vaccine, the surface antibody to hepatitis B can become positive, which indicates that immunity to the hepatitis B virus has been obtained and that one will not be infected with hepatitis B in the future because of exposure to the hepatitis B virus. There are some people who have been infected with hepatitis B but have cleared the virus through their own immunity. This may also be accompanied by a positive surface antibody to hepatitis B, but it may also be accompanied by a positive core antibody or e antibody to hepatitis B. If a person has only acquired antibodies and immunity through the hepatitis B vaccine, then the hepatitis B core antibody and hepatitis B e antibody will not be positive.