Question
Some doctors suggest that the Hepatitis B antibody can be lifelong effective, while others advise a booster shot every four or five years. How can one determine the level of antibody and when is it necessary to reinforce vaccination?
Answer
Based on a 15-year follow-up observation of children in Long’an County, Guangxi, who received the complete Hepatitis B vaccine series, the surface antigen positivity rate was 1.9% in the vaccinated group and 16.7% in the control group, with a protection rate of 88.6%. After 15 years, 50.9% of the children in the vaccinated group still maintained Hepatitis B antibodies. This shows that the immunity of the Hepatitis B vaccine can last for up to 15 years. Similar reports have also been made internationally. In Senegal, Africa, 12 years after receiving the Hepatitis B vaccine, the surface antigen positivity rate was 2% in the vaccinated group and 19% in the control group, with a protection rate of 88%, and 68% of the vaccinated children retained antibodies. Although antibody levels in recipients may gradually decrease over time, due to immune memory, antibody levels can rise again upon exposure to the Hepatitis B virus. This is particularly evident in high-incidence areas and high-risk populations. Therefore, for those who have completed the Hepatitis B vaccine series and produced high-titer antibodies, they may not need to be re-vaccinated within 10 years. However, for individuals, each recipient’s situation may vary, and specific analysis should be conducted for specific cases. For example, recently