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Occupational hepatitis B exposure in a documented vaccine responder — ABIM Board MCQ

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HardVaccinationOccupational hepatitis B exposure in a documented vaccine responderABIM Board

A 34-year-old surgical resident sustains a percutaneous injury from a hollow-bore needle immediately after it was used in a patient. The wound is washed promptly. The source patient tests positive for hepatitis B surface antigen. The resident has written documentation of a complete 3-dose hepatitis B vaccine series received 8 years ago and an anti-HBs concentration of 24 mIU/mL measured 6 weeks after the final dose. He has no immunocompromising condition. Employee health nevertheless measures his anti-HBs concentration today, which is 4 mIU/mL; HBsAg and total anti-HBc are negative. Which of the following is the most appropriate hepatitis B-specific management?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: B — Provide no HBIG, additional vaccination, or follow-up HBV serologic testing

Explanation lettering: D = shown as A · C = shown as B · B = shown as C · A = shown as D

This resident is a documented hepatitis B vaccine responder: he completed the vaccine series and had anti-HBs ≥10 mIU/mL when appropriately tested 1–2 months afterward. Immunocompetent responders have durable immune memory even when circulating anti-HBs subsequently falls below 10 mIU/mL. Therefore, no HBV postexposure prophylaxis, booster vaccination, or follow-up HBV testing is indicated, even though the source is HBsAg-positive. A is reserved for a documented nonresponder—anti-HBs <10 mIU/mL after two complete vaccine series—exposed to an HBsAg-positive or unknown-status source. B may be used when a clinician completed a series but has no documented prior response, currently has anti-HBs <10 mIU/mL, and the source is HBsAg-negative; the dose is followed by repeat testing. D is appropriate after exposure to an HBsAg-positive or unknown-status source when the clinician completed one series but never had response testing and now has anti-HBs <10 mIU/mL. E applies to an unvaccinated or incompletely vaccinated clinician exposed to an HBsAg-positive or unknown-status source. The low titer obtained today is a distractor: it does not negate the resident's previously documented protective response.

Reference: Responding to HBV Exposures in Health Care Settings (May 16, 2024) — https://www.cdc.gov/hepatitis-b/hcp/infection-control/index.html Table 1: Treatment for HBV Exposures in Health Care Settings (May 13, 2024) — https://www.cdc.gov/hepatitis-b/hcp/infection-control/table-1.html CDC Pink Book, Chapter 10: Hepatitis B (Checked August 27, 2026) — https://www.cdc.gov/pinkbook/hcp/table-of-contents/chapter-10-hepatitis-b.html