Among the five hepatitis B tests, a positive hepatitis B surface antibody means that there is a sufficient amount of hepatitis B surface antibody in the body. Hepatitis B surface antibody is a neutralizing antibody against hepatitis B surface antigen, which can neutralize the hepatitis B virus that enters the body through various transmission channels, prevent the hepatitis B virus from replicating in the body, and prevent the infection of hepatitis B virus, so hepatitis B surface antibody is a good antibody that has a preventive effect on the human body. The purpose of hepatitis B vaccination for newborns and adults without surface antibodies is to prevent the occurrence of hepatitis B virus infection by producing hepatitis B surface antibodies. However, hepatitis B surface antibodies do not exist for life. Currently, the average protection period through hepatitis B genetically engineered vaccination is 12 years, which means that the effective concentration of surface antibodies produced by the body will remain on average for 12 years after vaccination.