The initial dose of hepatitis B immune globulin for neonates is administered by which route?

• A. 0.5 ml intravenous (IV) injection
• B. 0.5 ml intramuscular (IM) injection
• C. 0.5 ml subcutaneous (SC) injection
• D. 0.5 ml intradermal (ID) injection

Answer: (B)

Hepatitis B immune globulin for newborns is given to provide immediate, passive protection, and the route is intramuscular in a 0.5 mL dose. The muscle tissue of the anterolateral thigh in neonates allows reliable, rapid absorption and predictable antibody levels, which are crucial to start protection within the first hours of life. Intramuscular injection is the form the product is prepared for, offering a consistent pharmacokinetic profile in newborns. Other routes—intravenous, subcutaneous, or intradermal—do not reliably achieve the necessary protective antibody levels in this setting and are not standard practice for HBIG in newborn prophylaxis. HBIG is typically given within 12 hours of birth, often alongside the hepatitis B vaccine but at a separate site and syringe.