What is the recommended Hepatitis B (HB) vaccine dosage for adults?

Hepatitis B Vaccine Dosage for Adults

The recommended hepatitis B vaccine dosage for adults depends on the specific vaccine product, with standard adult dosing being 10-20 μg administered in a series of 2-3 doses depending on the vaccine brand. 1

Standard Adult Dosing by Vaccine Type

Single-Antigen Vaccines

• Recombivax HB:

  • Adults ≥20 years: 10 μg (1.0 mL) per dose
  • Schedule: 3 doses at 0,1, and 6 months 1

• Engerix-B:

  • Adults ≥20 years: 20 μg (1.0 mL) per dose
  • Schedule: 3 doses at 0,1, and 6 months 1

• Heplisav-B:

  • Adults ≥18 years: 20 μg (0.5 mL) per dose
  • Schedule: 2 doses at 0 and 1 month 1

• PreHevbrio:

  • Adults ≥18 years: 10 μg (1.0 mL) per dose
  • Schedule: 3 doses at 0,1, and 6 months 1

Combination Vaccine

• Twinrix (Hepatitis A-Hepatitis B):
  • Adults ≥18 years: 20 μg HBsAg (1.0 mL) per dose
  • Standard schedule: 3 doses at 0,1, and 6 months
  • Accelerated schedule: 4 doses at 0,7,21-30 days, and 12 months 1

Special Populations

Hemodialysis Patients and Immunocompromised Adults

• Recombivax HB: 40 μg (1.0 mL) per dose, 3-dose series 1
• Engerix-B: 40 μg (2.0 mL) per dose, 4-dose series at 0,1,2, and 6 months 1

Important Considerations for Special Populations

• Heplisav-B and PreHevbrio have not been established as safe or effective for adults on hemodialysis 1
• For pregnant women requiring HBV vaccination, providers should use Engerix-B, Recombivax HB, or Twinrix rather than Heplisav-B or PreHevbrio due to insufficient data on vaccine-associated risks in pregnancy 1

Administration Guidelines

• Administer intramuscularly in the deltoid muscle for adults 1
• If the vaccination schedule is interrupted, the series does not need to be restarted 1
• For an interrupted 3-dose series:
  • If interrupted after first dose: Give second dose as soon as possible
  • Second and third doses should be separated by ≥8 weeks
  • Final dose must be administered ≥8 weeks after second dose and ≥16 weeks after first dose 1
• Minimum interval between first and second doses is 4 weeks 1

Vaccine Response and Efficacy

• The 3-dose vaccine series produces a protective antibody response in >90% of healthy adults under age 40 1
• Response rates decline with age:
  • Adults over 40: <90% response rate
  • Adults over 60: approximately 75% response rate 1
• Other factors affecting response include smoking, obesity, genetic factors, and immune suppression 1

Common Pitfalls to Avoid

1. Incorrect administration site: Always use deltoid muscle in adults, never the buttock (significantly reduces immunogenicity) 1

2. Improper dosing for special populations: Hemodialysis patients require higher doses and sometimes additional doses compared to the general population 1

3. Restarting interrupted series: If a series is interrupted, it doesn't need to be restarted - simply continue where left off 1

4. Mixing vaccines inappropriately: While completing a series with a different brand is acceptable, certain vaccines (Heplisav-B, PreHevbrio) have specific limitations for certain populations 1

5. Unnecessary antibody testing: Routine post-vaccination serologic testing is not needed for most healthy adults 1

The Advisory Committee on Immunization Practices now recommends universal hepatitis B vaccination for all adults aged 19-59 years, regardless of risk factors, which removes the need for risk factor screening and could increase vaccination coverage 1.