If a child’s test results show antigen, there is no need to get a booster shot. If the test shows a weakly positive antigen, it is recommended to get a booster shot. Currently, clinical practice mainly relies on measuring the titer of the hepatitis B surface antigen, and based on the test results, decide when it is appropriate to get a booster shot. If the hepatitis B surface antibody titer is below or equal to ten standard units/mL, it is recommended to get a booster shot within six months. If it exceeds ten standard units/mL, it is recommended to get a booster shot within six years.

Is it necessary to get a booster shot if there is an antigen in hepatitis B?

Is it necessary to get a booster shot if there is an antigen in hepatitis B? It depends on the situation. If the antigen in hepatitis B is not the surface antigen, but the e antigen or core antibody, a booster shot is not needed, and neither is the hepatitis B vaccine. If this antigen refers to the surface antigen, and the antibody is positive or the antigen quantitative analysis exceeds 100IU/L, a booster shot is not needed. Although the hepatitis B antibody will decrease slowly over time, it will still have a relatively long duration when it drops to around 10IU/L.

If the surface antigen of hepatitis B is below 100IU/L but above 10IU/L, it is considered to have antigen, and the test may be weakly positive. However, after a period of time, the antigen may drop below 10IU/L, losing the immune ability against hepatitis B, and a booster shot is needed to raise the surface antigen to above 100IU/L to obtain a stronger resistance against hepatitis B.

In addition, some experts and scholars believe that even if the surface antigen is reduced to below 10IU/L, it is possible not to be infected with the hepatitis B virus due to the memory of the human immune system. Therefore, if the antigen level is extremely low, below 10IU/L, there is no need to worry too much about being infected with hepatitis B. It is only necessary to go to the health and epidemic prevention station to receive a booster dose of the hepatitis B vaccine.