Hepatitis B antibody 15 does not need to be replenished for the time being, but it is usually necessary to re-vaccinate with Hepatitis B vaccine once after half a year. Antibody has a certain half-life in the body, and loses its original protective function when it drops to a certain level, and the antibody level can be produced and improved by re-vaccination. Generally speaking, if the highest value of Hepatitis B antibody titer is 10~100mIU/m1, it is recommended to take 1 shot after half a year. It is recommended that patients should regularly recheck the titer of hepatitis B antibody after booster injection of hepatitis B vaccine in order to prevent hepatitis B virus infection, and the time of rechecking is generally determined according to the titer of hepatitis B antibody: when the titer is 101~1000mIU/ml, the titer of hepatitis B antibody should be rechecked within 1~2 years after the first vaccination; when the titer is 1001~10000mIU/ml, the titer should be rechecked within 2~4 years; if the titer is greater than 10000mIU/ml, it can be rechecked in 4~6 years. When the highest value of Hepatitis B antibody titer is found to be less than 10mIU/ml, the vaccination should be repeated, that is to say, three Hepatitis B vaccines should be re-vaccinated according to the regularity, so as to stimulate the organism to produce antibodies and prevent viral infection.