What is the recommended treatment for Hepatitis B (HB) exposure using Hepatitis B Immunoglobulin (HBIG)?

Hepatitis B Immunoglobulin (HBIG) for Post-Exposure Prophylaxis

For Hepatitis B virus (HBV) exposure, HBIG should be administered as soon as possible (preferably within 24 hours) along with hepatitis B vaccine at a separate injection site, with treatment decisions based on the HBsAg status of the source and the vaccination/immune status of the exposed person. 1

Management Based on Vaccination Status and Source HBsAg Status

Unvaccinated or Incompletely Vaccinated Persons

• For exposure to HBsAg-positive source: Administer HBIG (0.06 mL/kg body weight) as soon as possible (preferably within 24 hours) AND begin hepatitis B vaccine series simultaneously at a separate anatomic site 1, 2
• For exposure to source with unknown HBsAg status: Begin hepatitis B vaccine series with first dose administered as soon as possible after exposure (preferably within 24 hours) 1
• The effectiveness of HBIG decreases significantly when administered >7 days after percutaneous exposure or >14 days after sexual exposure 1, 3

Previously Vaccinated Persons

• Persons with documented immunity (anti-HBs ≥10 mIU/mL): No HBIG, additional vaccination, or testing needed 1
• Persons with documented nonresponse to a complete 3-dose vaccine series:
  • If source is HBsAg-positive: Administer 1 dose of HBIG and begin a second 3-dose vaccine series 1
  • If source is HBsAg-negative: Complete revaccination series and undergo postvaccination testing 1
• Persons with documented nonresponse to two complete 3-dose vaccine series:
  • If source is HBsAg-positive: Administer 2 doses of HBIG, 1 month apart 1
  • If source is HBsAg-negative: No additional testing or treatment needed 1
• Persons with complete vaccination but unknown antibody response:
  • If source is HBsAg-positive: Test for anti-HBs immediately; if ≥10 mIU/mL, no treatment; if <10 mIU/mL, administer 1 dose of HBIG and 1 vaccine booster dose 1
  • If source has unknown HBsAg status: No treatment needed 1

Administration Guidelines

• HBIG dose: 0.06 mL/kg body weight, administered intramuscularly 1, 2
• Hepatitis B vaccine should be administered simultaneously with HBIG at a separate anatomic site 1, 2
• For infants born to HBsAg-positive mothers: HBIG (0.5 mL) should be administered within 12 hours of birth 2
• HBIG efficacy decreases markedly if treatment is delayed beyond 48 hours for perinatal exposure 2

Special Considerations

• For sexual exposure to an HBsAg-positive person: HBIG is 75% effective if administered within 2 weeks of last sexual exposure 2, 4
• For household exposure to persons with acute HBV infection: Prophylaxis with HBIG and hepatitis B vaccine is indicated for infants <12 months of age if the mother or primary caregiver has acute HBV infection 2
• Postvaccination testing should be performed 1-2 months after completing the vaccine series for healthcare personnel and other high-risk groups 1
• Testing after HBIG administration should be delayed until anti-HBs from HBIG is no longer detectable (4-6 months after administration) 1

Common Pitfalls to Avoid

• Delaying HBIG administration beyond 24 hours significantly reduces effectiveness, though recent research suggests it may still be effective up to 7 days post-exposure 5, 3
• Failing to administer HBIG and vaccine at separate anatomical sites 2
• Not completing the full hepatitis B vaccine series after exposure 1
• Assuming immunity without documented serologic testing after vaccination 5
• Not recognizing that persons with documented immunity (anti-HBs ≥10 mIU/mL) do not require HBIG after exposure 1

HBIG combined with hepatitis B vaccination provides both immediate and long-term protection against HBV infection, making it the preferred approach for post-exposure prophylaxis in most situations 2, 4.