When hepatitis B surface antibody <10mIU/ml is detected, one shot of hepatitis B vaccine can be injected as a booster shot at community hospitals. After the human body receives hepatitis B vaccine, the antibody level will gradually decline over time. According to the Chinese Guidelines for the Prevention and Control of Chronic Hepatitis B, after receiving hepatitis B vaccine, the protective effect of those who have antibody responders generally lasts for 12 years. Therefore, when the test is negative for both half pairs of Hepatitis B or the surface antibody of Hepatitis B is less than 10mIU/ml, it is necessary to have a booster injection of Hepatitis B vaccine. When choosing hepatitis B vaccine booster shot, try to choose hepatitis B vaccine with different production process from the original three shots, as the human body has different sensitivity to vaccines of different processes, which helps to produce hepatitis B antibody more effectively. If you are not sure, you can take a hepatitis B marker test and consult your doctor whether you need to take a booster shot according to the specific test results.