Do I need to get a booster shot if I have antibodies to hepatitis B? It depends on the situation. If the antibody you have is not surface antibody, but e antibody or core antibody, you do not need a booster shot, nor can you get the hepatitis B vaccine. If the antibodies are surface antibodies, a booster shot is not necessary if the antibodies are positive or if the antibody quantification is greater than 100 IU/L. This is because although hepatitis B antibodies will gradually decline over time, there will be a longer period of time when they drop to about 10 IU/L. If the surface antibody of hepatitis B is below 100 IU/L and greater than 10 IU/L, it is considered to have antibody and the test may be weakly positive. However, after some more time, the antibody will probably drop below 10 IU/L and lose immunity to hepatitis B. A booster shot is needed to get the surface antibody of hepatitis B up and above 100 IU/L to gain a stronger immunity to hepatitis B. In addition, some scholars believe that even if one has previously received hepatitis B vaccine and has surface antibodies, even if the antibodies drop below 10 IU/L, because the immune system has a memory, it is very likely that one will not be infected with hepatitis B virus at this time. Therefore, if one’s antibody level is very low, below 10 IU/L, there is no need to worry about getting infected with hepatitis B. One only needs to go to the immunization station for a supplementary hepatitis B vaccination.