About 5-10% of the normal population does not produce hepatitis B antibodies after vaccination, and individuals do not produce antibodies even after several courses of vaccination, which are mainly in the following cases: 1. The potency of hepatitis B vaccine is too low: the hepatitis B vaccine is now a recombinant hepatitis B surface antigen (HBsAg) of high purity manufactured through genetic engineering, which is a protein, like other protein-based drugs. It must be stored in the range of 2-8°C to be most stable. If the temperature is too low or too high during storage, transportation and use, the vaccine may freeze or coagulate and its immune effect may be reduced or lost. Therefore, it is best to receive the hepatitis B vaccine directly at the hospital or immunization station and not to take it out and bring it home or inject it at another place. 2. Individual children’s immune function is not yet well developed: the overall immune function of the body has a gradual process of improvement, and a few people may not produce antibodies or produce too few antibodies during childhood hepatitis B vaccination, which has no protective effect. 3.There are also some people who may be infected with a small amount of hepatitis B virus in childhood, and later, although the virus is cleared by the body’s non-specific immunity, the body has developed immune tolerance to the hepatitis B virus, and vaccination cannot produce antibodies. 4, there is another situation is that currently infected with hepatitis B virus, is in the window period or has become a chronic occult hepatitis B virus carriers. People in the window period will have hepatitis B antibodies in the next six months to two years, while occult hepatitis B carriers may gradually develop surface antigen positivity and become chronic hepatitis B. 5. Of course, patients who have recently suffered from immunocompromised diseases (such as chicken pox, typhoid, etc.) or are using immunosuppressive drugs will not easily produce hepatitis B antibodies with hepatitis B vaccination. When the above situation occurs, you should first consult a specialist to analyze and understand the possible causes, and if necessary, do the most sensitive and accurate quantitative hepatitis B surface antigen test (electrochemiluminescent HBsAg quantitative method) and quantitative hepatitis B surface antibody test (electrochemiluminescent anti-HBs quantitative method) to accurately determine the situation and standardize the treatment.