Why do I still get infected with the hepatitis B virus after being injected with the hepatitis B vaccine? It is almost a household name that hepatitis B vaccine is effective in preventing infection with hepatitis B virus. However, due to differences in quality, storage conditions, and the immune status of the vaccinees, 5% to 10% of people may have no immune response or only a low titer response after full immunization with the hepatitis B vaccine. These people may still be infected with hepatitis B virus. It is also reported that 1 month after the first dose of hepatitis B vaccine, only 30% of people have positive anti-HBs (surface antibodies). During this period, the vaccinated person may still develop disease due to hepatitis B virus infection. In addition, hepatitis B can be transmitted by injection. Hepatitis B can also occur if the needle is contaminated with the hepatitis B virus at the same time as the hepatitis B vaccination. Therefore, care should be taken to have one needle and two tubes for each person when injecting. How can I know that I have achieved the intended immunization effect after hepatitis B vaccination? You can find out by testing the anti-HBs level in the serum within 1 to 3 months after the full immunization with hepatitis B vaccine. If the anti-HBs level is positive or reaches the protection threshold, it indicates that the intended immunization effect has been achieved. Otherwise, the immunization should be booster again. Can the hepatitis B vaccine be given intrathecally in the buttocks? It has been shown in the literature that hepatitis B vaccine is much more effective when administered intramuscularly in the deltoid muscle of the upper arm than subcutaneously or intramuscularly in the buttocks. It has also been found abroad that intramuscular injection of hepatitis B vaccine in the buttocks is associated with a low response rate in the organism. Therefore, the hepatitis B vaccine should be strictly limited to intramuscular injections in the deltoid muscle of the upper arm, while infants and newborns can be injected intramuscularly in the anterolateral thigh. Do I have to get a booster dose of hepatitis B vaccine every 3 to 5 years? For people who have achieved the intended immunization effect, anti-HBs positivity can generally be maintained for 3 to 5 years. Theoretically, the hepatitis B vaccine should be given again every 3-5 years to consolidate its effect, but in clinical practice, it has been found that for people who have been successfully immunized, only one booster dose of hepatitis B vaccine is needed after 3-5 years to evoke the original memory cells, resulting in a long-lasting and stable immunity against anti-HBs, and it is not necessary to give a full immunization with hepatitis B vaccine every 3-5 years. There is no need for full immunization with hepatitis B vaccine every 3-5 years. According to clinical data, even if the serum anti-HBs is negative, the rate of hepatitis B virus infection is significantly reduced in those who have received full immunization. Therefore, some scholars argue that additional immunization is not necessary. In recent years, more in-depth studies have concluded that the immunoprophylactic effect cannot be guaranteed for those with low positive surface antibody levels, and that the ratio of surface antibody should be determined by releasing the vaccine, and if the test result is above 100-International Units, the booster injection can be suspended. Does the hepatitis B vaccine itself have any therapeutic effect on hepatitis B patients? The hepatitis B vaccine can prevent the infection of hepatitis B virus and promote the body to produce anti-HBs for protection, but it has no therapeutic effect on hepatitis B patients. o The clinical application of hepatitis B vaccine in combination with immunomodulators for the treatment of hepatitis B is to stimulate the body’s immune system with the help of its reinforcement, improve the immune response and produce protective antibodies, so as to achieve the purpose of inhibiting the replication of hepatitis B virus. What are the indicators of successful hepatitis B vaccination? The level of surface antibodies is measured 1~3 months after hepatitis B vaccination, and the response of each person, i.e. immune response, can be different. (2) Weak response, the anti-HBs produced are 2 to 10 international units. (3) Low response, producing anti-HBs of 10 to 100 international units. (4) Good response, producing anti-HBs of 100 international units or more. The non-responders and weak responders account for 5-10% of these people, who should try to be reinjected or tested, and if they are low responders, it is better to have the 4th vaccination after 6 months.