March 18 is National Hepatitis Day, and hepatitis B vaccination is the most effective way to prevent hepatitis B virus infection. However, many readers are still confused about hepatitis B immunization. What does “effective response, low response and no response” mean for hepatitis B vaccination? Hepatitis B vaccination consists of 3 injections, the second and third injections are given 1 month and 6 months respectively after the first injection, so it is called the “0-1-6 months immunization program”. When a person produces enough antibodies after receiving the hepatitis B vaccine, the doctor says that he or she has received an effective immune response (referred to as an effective response or a normal response). People with low or no response have little or no resistance to the hepatitis B virus and may still be infected with the hepatitis B virus. What are the reasons for no or low response to hepatitis B vaccination? There are many reasons affecting the response to hepatitis B vaccination, including the vaccine and the human body itself. First, it is related to insufficient vaccine dose. From the vaccination situation of hepatitis B vaccine in China for many years, the effect of using recombinant yeast hepatitis B vaccine with a dose of 10 micrograms is significantly better than that with a dose of 5 micrograms. Therefore, the 2010 edition of the Guidelines for the Prevention and Control of Chronic Hepatitis B increased the recommended dose of 5 micrograms to 10 micrograms in 2005. Second, it is related to the quality of vaccine preservation and vaccination. Third, it is related to genetic factors. It is found that if parents do not produce antibodies after receiving hepatitis B vaccine, the incidence of their children having no or low response is high; if parents are infected with hepatitis B virus, their children’s response to hepatitis B vaccine is poorer. Fourth, already infected by hepatitis B virus. About 20% of the non-responders are infected with hepatitis B virus, and most of them are transmitted from mother to child. Those who have been infected with hepatitis B virus will not respond to hepatitis B vaccine. Fifth, those who suffer from some diseases that affect the immune system, such as AIDS, diabetes, tumors, etc., which lead to low immune function of the body, will not respond well to hepatitis B vaccination. What should I do if I have no or low response to hepatitis B vaccination? The majority of healthy non-responders are not absolutely non-responders to hepatitis B vaccine. Increasing the vaccination dose and the number of shots (booster immunization) can effectively improve their antibody response level. According to a study, after strengthening immunization for non-responding children according to the “0-1-6 months immunization program”, 70% of the children in the 5-microgram dose group produced antibodies, and 91% of the children in the 10-microgram dose group produced antibodies; 61% of the children in the 1-dose strengthening immunization group achieved a normal response, and 85% of the children in the 3-dose strengthening immunization group achieved a normal response. Therefore, booster immunization is considered to be the easiest and currently practicable way to solve the problem of low/no response to hepatitis B vaccine. How to do booster immunization for Hepatitis B vaccine? There is no need to monitor anti-HBs in general population after hepatitis B vaccination, because the effective antibody of hepatitis B vaccination can be maintained for 12 years, and the immune system has a strong “memory”, even if the antibody disappears, when hepatitis B virus invades into the human body, the immune system will quickly produce antibody to clear the invading enemy. However, for the high-risk groups of hepatitis B virus infection, such as parents or spouses of hepatitis B virus infected people, medical personnel, people who often receive blood transfusion or blood products, immunocompromised people, etc., should be monitored after hepatitis B vaccination anti-HBs.