What is the recommended dosage and schedule for hepatitis B revaccination, including recommendations for high‑risk groups and pregnant patients?

Hepatitis B Revaccination: Dosage and Schedule

Revaccination is not routinely recommended for immunocompetent individuals who completed the primary vaccine series, but specific high-risk populations require revaccination when anti-HBs levels fall below 10 mIU/mL, using standard age-appropriate dosing with serologic testing 1-2 months after completion. 1

General Principles for Immunocompetent Persons

• Routine booster doses are not recommended for persons with normal immune status who were vaccinated as infants, children, adolescents, or adults, regardless of subsequent antibody decline. 1
• Immunologic memory provides long-term protection even when anti-HBs levels drop below 10 mIU/mL in vaccine responders. 1
• There is no maximum number of booster doses if revaccination becomes necessary. 1

High-Risk Populations Requiring Revaccination

Healthcare Personnel (HCP)

For HCP with documented complete vaccination but anti-HBs <10 mIU/mL:

• Administer one additional dose of hepatitis B vaccine (20 mcg for adults), followed by anti-HBs testing 1-2 months later. 1
• If anti-HBs remains <10 mIU/mL after the single dose, complete a second full 3-dose series (usually 6 doses total when accounting for the original series). 1
• Retest anti-HBs 1-2 months after the final dose to document vaccine response status. 1

Hemodialysis Patients

• Use 40 mcg dose (two 20 mcg injections) on a 0,1,2,6-month schedule for initial vaccination. 2
• Perform annual anti-HBs testing and administer 40 mcg booster doses when antibody levels decline below 10 mIU/mL. 1, 2
• This population has less complete vaccine-induced protection that persists only as long as antibody levels remain above 10 mIU/mL. 2

Infants Born to HBsAg-Positive Mothers

For HBsAg-negative infants with anti-HBs <10 mIU/mL after primary series:

• Administer one dose of hepatitis B vaccine (10 mcg/0.5 mL for infants), and retest 1-2 months later. 1
• If anti-HBs remains <10 mIU/mL after single dose revaccination, administer two additional doses to complete a second series, followed by anti-HBs testing 1-2 months after the final dose. 1
• Alternative approach: Administer a complete second 3-dose series and retest (HBsAg and anti-HBs) 1-2 months after the final dose. 1

Other Immunocompromised Persons

• HIV-infected persons, hematopoietic stem-cell transplant recipients, and persons receiving chemotherapy require revaccination when anti-HBs <10 mIU/mL. 1
• Administer 3 additional doses on an appropriate schedule (0,1,6 months), followed by anti-HBs testing 1-2 months after the final dose. 1

Standard Dosing by Age Group

Primary Series Dosing

• Infants and children (birth through 10 years): 10 mcg/0.5 mL at 0,1,6 months 2
• Adolescents (11-19 years): 10 mcg/0.5 mL at 0,1,6 months (or 20 mcg/1.0 mL as alternative) 2
• Adults (>19 years): 20 mcg/1.0 mL at 0,1,6 months 2
• Adult hemodialysis patients: 40 mcg/2.0 mL at 0,1,2,6 months 2

Booster Dosing

• Children ≤10 years: 10 mcg 2
• Adolescents 11-19 years: 20 mcg 2
• Adults: 20 mcg 2
• Hemodialysis patients: 40 mcg 2

Interrupted Vaccination Series

• Never restart the series if interrupted at any point; simply continue where it was left off. 3
• Administer the second dose as soon as possible, with a minimum interval of 4 weeks between doses 1 and 2. 3
• The third dose must be given at least 8 weeks after dose 2 and at least 16 weeks after dose 1. 3
• Doses administered ≤4 days before the minimum interval are considered valid and do not need to be repeated. 3

Post-Revaccination Testing

• Measure anti-HBs levels 1-2 months after the final dose of the revaccination series. 1
• Seroprotection is defined as anti-HBs ≥10 mIU/mL. 1
• Post-vaccination testing is specifically recommended for HCP, hemodialysis patients, HIV-infected persons, other immunocompromised individuals, sex partners of HBsAg-positive persons, and infants born to HBsAg-positive mothers. 1

Special Considerations for Pregnant Patients

• The guidelines do not provide specific modifications for pregnant patients regarding revaccination schedules. 1
• Standard age-appropriate dosing and schedules should be followed, as hepatitis B vaccine is not contraindicated in pregnancy. 1

Common Pitfalls to Avoid

• Do not routinely test or revaccinate immunocompetent individuals with declining antibody levels after documented vaccine response. 1
• Do not restart an interrupted series; continue from where it was left off while respecting minimum intervals. 3
• Do not use subcutaneous administration unless the patient is at risk of hemorrhage with intramuscular injections, as this results in lower antibody titers. 2
• For persons who fail to respond to two complete vaccine series (usually 6 doses total), do not administer additional doses; these individuals should receive HBIG for known exposures to HBsAg-positive sources. 1