What is the recommended schedule and dosage for the Hepatitis B (HBV) vaccine, including Engerix-B (Hepatitis B vaccine (recombinant)) and Recombivax HB (Hepatitis B vaccine (recombinant))?

Hepatitis B Vaccine: Recommended Schedules and Dosing

For most populations, administer hepatitis B vaccine as a 3-dose series at 0,1, and 6 months using standard age-appropriate dosing, with the critical exception that all infants should receive their first dose within 12 hours of birth regardless of maternal HBsAg status. 1

Standard Dosing by Age and Product

Infants and Children

• Recombivax HB: 5 μg (0.5 mL) at 0,1-2, and 6 months 1
• Engerix-B: 10 μg (0.5 mL) at 0,1-2, and 6 months 1
• Critical timing: First dose must be given within 12 hours of birth, before hospital discharge 2, 3
• Final dose timing: Do not administer before 24 weeks (164 days) of age, regardless of when earlier doses were given 1

Adolescents (11-19 years)

• Standard 3-dose schedule: Recombivax HB 10 μg or Engerix-B 10 μg at 0,1, and 6 months 1
• Alternative 2-dose schedule: Recombivax HB adult formulation (10 μg) at 0 and 4-6 months for ages 11-15 years only 1

Adults (≥20 years)

• Recombivax HB: 10 μg (1 mL) at 0,1, and 6 months 1
• Engerix-B: 20 μg (1 mL) at 0,1, and 6 months 1
• Heplisav-B: 20 μg (0.5 mL) at 0 and 1 month (2-dose series) 1
• PreHevbrio: 10 μg (1 mL) at 0,1, and 6 months 1
• Twinrix (HepA-HepB combination): 20 μg HepB component (1 mL) at 0,1, and 6 months (standard) or 0 days, 7 days, 21-30 days, and 12 months (accelerated) 1

Special Populations Requiring Modified Dosing

Hemodialysis Patients and Immunocompromised Adults

• Recombivax HB: 40 μg (1 mL) at 0,1, and 6 months 1
• Engerix-B: 40 μg (2 mL) at 0,1,2, and 6 months (4-dose series) 1
• Annual anti-HBs testing required: Administer booster when levels fall below 10 mIU/mL 1
• Critical pitfall: Never use standard adult doses in hemodialysis patients—they require double the dose 1, 2

Pregnant Women

• Use only: Engerix-B, Recombivax HB, or Twinrix 1
• Do not use: Heplisav-B or PreHevbrio due to insufficient safety data in pregnancy 1, 2

Infants Born to HBsAg-Positive Mothers

• Within 12 hours of birth: First vaccine dose PLUS hepatitis B immune globulin (HBIG) 0.5 mL at separate anatomical sites 1, 4
• Subsequent doses: At 1-2 months and 6 months 1
• Post-vaccination testing: Check HBsAg and anti-HBs at 9-15 months of age 2, 3
• Critical warning: Delaying the birth dose beyond 12 hours significantly increases infection risk 2, 3

Infants <2000 g Born to HBsAg-Positive Mothers

• Birth dose: Give within 12 hours plus HBIG, but this dose does not count toward the series 1
• Restart series: At 1 month of age or hospital discharge, then at 2-3 months and 6 months (total of 4 doses) 1

Minimum Dosing Intervals (Critical for Validity)

• Between doses 1 and 2: Minimum 4 weeks 1, 2
• Between doses 2 and 3: Minimum 8 weeks 1, 2
• Between doses 1 and 3: Minimum 16 weeks 1, 2
• Grace period: Doses given ≤4 days before the minimum interval are considered valid 1, 2
• Exception: The 4-day grace period does NOT apply to the first 3 doses of Twinrix on the accelerated schedule 1

Interrupted Schedules: Never Restart

If the vaccination series is interrupted at any point, do not restart—simply continue where you left off. 1, 2

If Interrupted After Dose 1

• Give dose 2 as soon as possible 1
• Ensure doses 2 and 3 are separated by at least 8 weeks 1
• Ensure dose 3 is given at least 16 weeks after dose 1 1

If Only Dose 3 Is Delayed

• Give dose 3 as soon as possible 1
• Ensure it is at least 8 weeks after dose 2 and at least 16 weeks after dose 1 1

Switching Manufacturers

• No need to restart if different brands are used for different doses 1
• Immunogenicity is equivalent when switching manufacturers 1

Post-Vaccination Serologic Testing

Populations Requiring Testing (1-2 months after series completion)

• Infants born to HBsAg-positive mothers (test at 9-15 months) 1, 3
• Healthcare personnel and public safety workers 1, 3
• Hemodialysis patients 1, 3
• HIV-infected persons and other immunocompromised individuals 1, 3
• Sex partners of HBsAg-positive persons 1

Interpretation and Management

• Anti-HBs ≥10 mIU/mL: Adequate protection achieved 1, 3
• Anti-HBs <10 mIU/mL in healthcare workers: Give 1 additional dose, retest in 1-2 months; if still <10 mIU/mL, complete a second full series (6 doses total), then retest 1

Alternative Schedules with Similar Efficacy

While the 0,1,6-month schedule is standard, alternative schedules produce similar seroprotection rates 1, 2:

• 0,2,4 months: Acceptable when ensuring follow-up is difficult 2
• 0,1,4 months: Produces similar final antibody levels 1
• 0,12,24 months: Highly immunogenic for low-risk children (>98% seroprotection), though not routinely recommended 5

Longer intervals between the last 2 doses result in higher final antibody titers, but may increase short-term infection risk in high-risk individuals 1, 2

Common Pitfalls to Avoid

• Never restart an interrupted series—this wastes doses and delays protection 1, 2
• Never give dose 3 before 16 weeks from dose 1, even if 8 weeks have passed since dose 2 1, 2
• Never give the final infant dose before 24 weeks of age—this may compromise long-term immunity 1, 2
• Never use standard adult doses in hemodialysis patients—they require 40 μg doses 1, 2
• Never use Heplisav-B or PreHevbrio in pregnant women, children, or hemodialysis patients 1, 2
• Never delay the birth dose beyond 12 hours in infants of HBsAg-positive mothers—infection risk increases dramatically 2, 3, 4
• Never count the birth dose in infants <2000 g born to HBsAg-positive mothers toward the series—restart at 1 month 1

Immunogenicity Expectations

• After dose 1: 30-55% achieve protective antibody levels 2
• After dose 2: 75% achieve protection 2
• After dose 3: >90% achieve protection with traditional vaccines 2
• Heplisav-B: Achieves approximately 90% seroprotection compared to 70.5-90.2% with Engerix-B 2
• Duration: Vaccine-induced immunity persists for >30 years 2