What is the proper dosage of hepatitis B immune globulin (HBIG) for an infant born to a hepatitis B-positive mother?

The proper dosage of hepatitis B immune globulin (HBIG) for an infant born to a hepatitis B-positive mother is 0.5 mL administered intramuscularly within 12 hours of birth. This timing and dosage are critical for ensuring that the infant receives passive immunity against the hepatitis B virus as soon as possible after birth.

Administering HBIG intramuscularly allows for effective absorption and prompt response in the infant's immune system. The timing within the first 12 hours is essential, as it maximizes the protective effect against potential infection from the mother during labor and delivery. HBIG works by providing immediate antibodies to the hepatitis B virus, which is particularly important for infants at high risk of infection due to maternal hepatitis B positivity.

In contrast, administering the solution subcutaneously could lead to less effective absorption of the globulin, making that option less favorable. Additionally, giving HBIG intravenously is not a standard practice for newborns in this context, as it may pose unnecessary risks and does not align with the typical guidelines for preventing hepatitis B infection in newborns. The dosage of 1.0 mL is not consistent with the standard recommendation of 0.5 mL in this situation, further undersc