According to the guidelines for the prevention and treatment of chronic hepatitis B, when the surface antibody against hepatitis B is less than 10 mIU/mL, it is necessary to consider catching up on the vaccine, that is to say, receiving a booster shot. Hepatitis B vaccine belongs to Class I vaccine in China, which has the effect of preventing viral hepatitis B. The vaccination can stimulate the body to produce protective antibodies, which can resist the invasion of hepatitis B virus. For the body, hepatitis B surface antibody >10mIU/mL is positive, and the higher the value, the stronger the protection against hepatitis B virus. Although it is said that hepatitis B vaccination can effectively improve the value of hepatitis B surface antibody, but in the case of vaccination for a long time, the value of hepatitis B surface antibody in the body will continue to decline, and once it is lower than 10mIU/mL, it should be timely inoculated with booster shots. If you find that the level of hepatitis B surface antibody in your body is low, especially for those who are at high risk of hepatitis B, you must pay high attention to it, and you can maintain your personal health by taking booster shots.