## Management of Hepatitis B Immunisation in Infants Born to HBsAg-Positive Mothers ### Clinical Context This infant has already received appropriate passive and active immunisation at birth (HBV vaccine + HBIg). The question tests knowledge of the follow-up immunisation schedule for such high-risk infants. ### Key Point: **Infants born to HBsAg-positive mothers should continue the standard HBV vaccination schedule (0, 1, 6 months) regardless of maternal HBeAg status.** The initial dose at birth plus HBIg provides immediate passive protection while active immunity develops. ### High-Yield: **Standard schedule continuation is the correct approach.** After the birth dose + HBIg, the infant receives doses at 1 month and 6 months as per the normal IAP schedule. Anti-HBs titre should be checked at 9 months (post-vaccination) to confirm seroconversion. ### Clinical Pearl: **Maternal HBeAg status determines risk stratification but does NOT change the vaccination schedule:** - HBeAg-positive mothers: higher viral load, higher transmission risk → but vaccination schedule remains the same - HBeAg-negative mothers: lower risk → same schedule applies The schedule is uniform; only the interpretation of titre results may differ slightly by maternal status. ### Why Anti-HBs Testing at 9 Months? - Confirms adequate immune response (target: anti-HBs ≥10 mIU/mL) - Identifies non-responders who may need additional doses or investigation - Provides prognostic information about long-term protection ### Table: HBV Immunisation in High-Risk Infants | Timing | Intervention | Rationale | | --- | --- | --- | | At birth (within 12 hrs) | HBV vaccine + HBIg | Passive + active protection | | 1 month | HBV vaccine | Continue active immunisation | | 6 months | HBV vaccine (3rd dose) | Complete primary series | | 9 months | Anti-HBs titre check | Assess seroconversion | [cite:IAP Immunisation Schedule 2023, Park 26e Ch 6]
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.