Patient's question:
Why do some doctors say that hepatitis B antibodies are lifelong effective, while others say to get a booster shot every four or five years? Additional question: How can one determine the level of antibodies? At what level does it become necessary to get a booster?Doctor's answer:
Hello, a 15-year follow-up observation in our country on children in Long'an County, Guangxi who have been vaccinated against hepatitis B showed that the positive rate of hepatitis B surface antigen in the vaccinated group was 1.9%, while in the control group it was 16.7%, with a protection rate of 88.6%. At 15 years, 50.9% of the vaccinated group had a positive hepatitis B antibody. This indicates that the immune persistence of the hepatitis B vaccine can last for up to 15 years. Similar reports have also been made abroad. In Senegal, Africa, 12 years after vaccination against hepatitis B, the positive rate of hepatitis B surface antigen in the vaccinated group was 2%, while in the control group it was 19%, with a protection rate of 88%. Among children vaccinated against hepatitis B, 68% had a hepatitis B antibody. Although the antibody levels of vaccinated individuals may gradually decline over time, due to immune memory, their antibody levels can rise again when exposed to the hepatitis B virus. This is particularly evident in high-prevalence and high-risk areas and populations. Therefore, as a general rule, if a full course of hepatitis B vaccination is completed and high-titer hepatitis B antibodies are produced after vaccination, revaccination may not be necessary within 10 years.However, on an individual basis, each vaccinated person's situation may be different. Therefore, specific cases should be analyzed individually. For example, the latest national hepatitis B vaccination coverage survey showed that the rate of full-course qualified vaccination in our country was only 28.4%, with 73.6% being non-full-course vaccination. Children who received non-full-course vaccination may not have hepatitis B antibodies or may have low antibody titers. Such children should be tested for hepatitis B antibodies. If no antibodies are produced or if existing antibodies have disappeared, revaccination should be administered promptly. It is worth noting that even after full-course hepatitis B vaccination, 5% to 10% of vaccinated individuals may not produce hepatitis B antibodies or may only produce low-titer antibodies. These children with no response or low response should be repeatedly vaccinated against hepatitis B until antibodies are produced. Additionally, for children with a high risk of hepatitis B infection, such as those with family members or parents who are hepatitis B carriers, their antibody levels and hepatitis B infection indicators should be monitored regularly. If the antibody levels drop to a low level or completely disappear, revaccination should be administered promptly.