What is the recommended post-exposure prophylaxis (PEP) for a patient exposed to hepatitis B (HBV)?

Post-Exposure Prophylaxis for Hepatitis B

For unvaccinated persons exposed to HBsAg-positive blood, administer both HBIG (0.06 mL/kg) and hepatitis B vaccine simultaneously at separate anatomic sites as soon as possible, preferably within 24 hours. 1, 2, 3

Immediate Wound Care

• Wash wounds and skin thoroughly with soap and water immediately after any percutaneous, ocular, or mucous membrane exposure 1, 4
• Flush mucous membranes with water 1, 4
• Do not apply caustic agents like bleach or inject antiseptics into wounds 1

Risk Assessment & Source Testing

• Test the source patient for HBsAg as soon as possible after exposure 1
• Simultaneously assess the exposed person's hepatitis B vaccination history and documented anti-HBs status 1
• Do not delay prophylaxis while waiting for source testing results if high suspicion exists 2, 4

Management Based on Vaccination Status

Unvaccinated or Incompletely Vaccinated Persons

HBsAg-Positive Source:

• Administer HBIG 0.06 mL/kg IM as soon as possible, preferably within 24 hours (effectiveness unclear beyond 7 days) 1, 3
• Give first dose of hepatitis B vaccine simultaneously at a separate anatomic site (e.g., separate limb) 1
• Complete the 3-dose vaccine series at 0,1, and 6 months 1, 3
• Recent evidence suggests HBIG may remain effective when given between 24 hours and 7 days post-exposure, though earlier is strongly preferred 5

Unknown HBsAg Source:

• Initiate hepatitis B vaccine series immediately, preferably within 24 hours 1
• Complete the vaccine series according to schedule 1
• HBIG is not required for unknown source exposures 1

Fully Vaccinated Persons (Completed 3-Dose Series)

With Documented Anti-HBs ≥10 mIU/mL:

• No postexposure prophylaxis needed regardless of source HBsAg status 1
• No testing required 1

Without Previous Anti-HBs Testing:

• Test the exposed person for anti-HBs immediately 1
• Test source patient for HBsAg simultaneously 1
• If anti-HBs <10 mIU/mL and source is HBsAg-positive: Give 1 dose HBIG plus initiate second 3-dose vaccine series (total 6 doses) 1
• If anti-HBs <10 mIU/mL and source is HBsAg-negative: Give single vaccine booster dose 1
• If anti-HBs ≥10 mIU/mL: No prophylaxis needed 1

With Written Documentation but No Postvaccination Testing:

• Give single hepatitis B vaccine booster dose if source is HBsAg-positive 1
• No treatment needed if source is HBsAg-negative or unknown 1

Known Vaccine Non-Responders (Anti-HBs <10 mIU/mL After 6 Total Doses)

HBsAg-Positive Source:

• Administer 2 doses of HBIG (0.06 mL/kg each), given 1 month apart 1, 3
• No additional vaccination needed 1
• These individuals should be counseled they remain susceptible to HBV and require HBIG for any future known exposures 1

Unknown or HBsAg-Negative Source:

• No prophylaxis required 1

Special Exposure Types

Sexual Exposure

• Administer HBIG 0.06 mL/kg within 14 days of last sexual contact with HBsAg-positive person 2
• Initiate or complete hepatitis B vaccine series 1

Perinatal Exposure (Infants Born to HBsAg-Positive Mothers)

• Administer HBIG 0.5 mL IM within 12 hours of birth 2, 3
• Give hepatitis B vaccine 0.5 mL (10 μg) within 7 days of birth at separate site 2, 3
• Complete vaccine series at 1 and 6 months 3
• Efficacy decreases markedly if HBIG delayed beyond 48 hours 3

Follow-Up Testing

• For persons who received HBIG, perform anti-HBs testing 4-6 months after administration (when HBIG antibodies are no longer detectable) 1
• For persons who received vaccine only, test anti-HBs 1-2 months after final vaccine dose 1
• Protective anti-HBs level is ≥10 mIU/mL 1

Critical Pitfalls to Avoid

• Never delay HBIG administration while waiting for source or exposed person test results 2, 4
• Do not test discarded needles or syringes for virus contamination—focus on source patient testing 1, 4
• Do not confuse hepatitis B protocols with hepatitis C (no immunoglobulin or vaccine exists for HCV) 2, 4
• Ensure HBIG and vaccine are given at separate anatomic sites to avoid interference 1
• The 24-hour window is ideal, but prophylaxis may retain efficacy up to 7 days for percutaneous exposures and 14 days for sexual exposures 1, 5