Hepatitis B Post-Exposure Prophylaxis (PEP)

Hepatitis B Post-Exposure Prophylaxis (PEP)

Definition

Hepatitis B post-exposure prophylaxis (PEP) is the administration of hepatitis B immune globulin (HBIG) and/or hepatitis B vaccine to susceptible individuals following exposure to blood or body fluids from a person infected with hepatitis B virus (HBV), with the aim of preventing infection.

Common Exposure Situations

• Needle-stick injuries

• Sharps injuries

• Mucosal exposure to blood or body fluids

• Sexual exposure to an HBsAg-positive individual

• Household exposure involving blood contact

• Neonates born to HBsAg-positive mothers

Assessment

• Determine source patient's HBsAg status.

• Determine exposed person's HBV vaccination status.

• Assess timing and type of exposure.

• Baseline HBsAg and anti-HBs testing where available.

Investigations

• HBsAg

• Anti-HBs antibody titre

• Anti-HBc (if indicated)

Pharmacological Treatment

For HBsAg-negative individuals exposed to an HBsAg-positive source:

hepatitis B immune globulin (HBIG) (IM) 0.06 mL/kg once

AND

hepatitis B vaccine (HBV) (IM) 1 mL (20 mcg) at 0, 1 and 6 months

Special Considerations

• Administer HBIG and HBV vaccine at different intramuscular sites.

• PEP should ideally be initiated within 24 hours of exposure.

• Efficacy decreases substantially after 72 hours.

• Previously vaccinated individuals with documented protective anti-HBs levels generally do not require PEP.

Follow-up

• Repeat HBsAg and anti-HBs testing according to local protocol to confirm protection and exclude infection.

Note

HBIG provides immediate passive immunity, while hepatitis B vaccine induces long-term active immunity. Both should be administered as soon as possible after significant exposure to HBV.