Question
When should newborns receive the second dose of Hepatitis B immune globulin?
Answer
The second dose of Hepatitis B immune globulin should be administered 15 days after birth. If the first dose was administered on the third day after birth and the core antibody (HBcAb) test is positive, it indicates that the newborn is in the core window period of acute HBV infection. During this period, HBsAg has disappeared, but HBsAb has not yet appeared, so only HBcAb can be detected. This stage is known as the window period. In this situation, the newborn should receive the second dose of Hepatitis B immune globulin 15 days after birth to enhance the immune effect.