If you have hepatitis B vaccine antibodies, you do not need to get another hepatitis B vaccine. This is because hepatitis B surface antibody is a protective antibody that protects the body from infection with the hepatitis B virus, which can be removed and blocked when the hepatitis B virus is present. The higher the titer of hepatitis B surface antibody, the better the protection for the body. It is generally believed that a titer of hepatitis B surface antibody greater than 100 IU has a good protective effect on the human body. If the titer of hepatitis B surface antibody is less than 10 IU, the protection is poor, so it can be weakly positive at this time, and the hepatitis B vaccine can be given to enhance the immunity and increase the titer of hepatitis B surface antibody to achieve better protection.