If your boyfriend has hepatitis B, you should first go to the hospital to check the five hepatitis B items because your boyfriend’s saliva and semen will contain hepatitis B virus, and you can be infected with hepatitis B virus through body fluids if you come into contact with the above body fluids through kissing or sexual intercourse. However, there are protective antibodies, i.e. surface antibodies, which can neutralize the hepatitis B virus even if it enters the body, and the hepatitis B virus cannot multiply in the body, so hepatitis B virus infection will not occur. If the surface antibodies are positive or the surface antibodies are greater than 100 mIU/ml in the quantitative test, there is no need to vaccinate against hepatitis B. If you are weakly positive or negative for hepatitis B surface antibodies, you do not have protective antibodies in your body, so it is important to receive the hepatitis B vaccine in a timely manner to prevent infection with the hepatitis B virus.