Question
The child was vaccinated against Hepatitis B at birth and later had a Hepatitis B series test at kindergarten, which all came back negative. Subsequently, one dose of vaccine was administered at the kindergarten. Now, at the age of 10, the results of the Hepatitis B series test showed that the second item, surface antibody, was weakly positive. Is it necessary to re-vaccinate against Hepatitis B?
Answer
Generally speaking, there is no need to re-vaccinate in this situation. However, you can consider undergoing a quantitative test for the Hepatitis B series. If the concentration of the surface antibody is below 100 units, you may consider re-vaccinating.