The ability to produce antibodies after vaccination is related to the vaccine, the immunization protocol, the injection site, and other factors. The dose and purity of the vaccine are common issues, and some people who do not produce antibodies can develop antibodies after applying a higher purity or increasing the dose of the vaccine injected. For individuals, not producing antibodies is also related to the following reasons: 1. Immunity: Some people have low immunity due to some diseases (such as AIDS) or suffer from diseases such as systemic lupus erythematosus that require long-term application of glucocorticoids, which do not easily produce antibodies. 2, occult infection: people with occult infection check the surface antigen of hepatitis B virus is negative, but in the serum or liver tissue can be detected in low titers of viral replication, after vaccination does not produce antibodies, this easily overlooked situation is a more common reason for not producing antibodies. In addition, failure to produce antibodies may be related to a variety of factors, including genetics.