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 hepatitis B antibody positivity. 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 hepatitis B antibody. Although the antibody levels of vaccinated individuals may decline gradually over time, due to immune memory, their antibody levels can rise again when they are exposed to the hepatitis B virus. This is particularly evident in high-prevalence and high-risk areas and populations. Therefore, overall, 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, so a specific analysis should be conducted for each case. For example, the latest national hepatitis B vaccination coverage survey showed that the qualified full vaccination rate in our country was only 28.4%, with 73.6% being non-full vaccination. Children who did not receive a full course of vaccination may have no hepatitis B antibodies or low antibody titers, and such children should be tested for hepatitis B antibodies. If no antibodies are produced or if existing antibodies have disappeared, timely revaccination should be administered. It is worth noting that even after receiving a full course of hepatitis B vaccination, 5% to 10% of vaccinated individuals may not produce hepatitis B antibodies or only produce low-titer antibodies. These non-responders or low-responders should receive multiple doses of hepatitis B vaccine 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, timely revaccination should be administered.