What is the typical dosing regimen for Hepatitis A and B vaccines (Hepatitis A vaccine and Hepatitis B vaccine)?

Hepatitis A and B Vaccine Dosing Regimens

The standard dosing regimen for hepatitis B vaccination in adults is a 3-dose series administered at 0,1, and 6 months, while Heplisav-B offers a more convenient 2-dose schedule at 0 and 1 month with comparable efficacy. 1, 2

Hepatitis B Vaccine Options and Dosing

Standard Adult Dosing (Age ≥18 years)

• For adults ≥20 years, Recombivax HB is administered as 10 μg (1.0 mL) per dose in a 3-dose schedule at 0,1, and 6 months 2
• For adults ≥20 years, Engerix-B is administered as 20 μg (1.0 mL) per dose in a 3-dose schedule at 0,1, and 6 months 2
• For adults ≥18 years, Heplisav-B is administered as 20 μg (0.5 mL) per dose in a 2-dose schedule at 0 and 1 month 1, 2
• Clinical trials have shown that Heplisav-B achieves approximately 90% protective antibody response compared to 70.5%-90.2% with Engerix-B 1

Special Populations

• For hemodialysis patients and immunocompromised adults ≥20 years:
  • Recombivax HB: 40 μg (1.0 mL) per dose in a 3-dose schedule 1, 2
  • Engerix-B: 40 μg (2.0 mL) per dose in a 4-dose schedule at 0,1,2, and 6 months 1, 2
• Annual anti-HBs testing and booster doses should be considered for hemodialysis patients when anti-HBs levels decline to <10 mIU/mL 1

Combined Hepatitis A and B Vaccine (Twinrix)

• For adults ≥18 years, Twinrix is administered as a 3-dose series at 0,1, and 6 months 1, 2
• Alternatively, a 4-dose accelerated schedule can be used with doses administered on days 0,7, and 21-30, followed by a booster dose at 12 months 1
• The combined vaccine has been shown to elicit similar immune responses to the individual vaccines 3

Interrupted Schedules and Minimum Intervals

• If the hepatitis B vaccine schedule is interrupted, the series does not need to be restarted 1, 2
• For interrupted 3-dose series, the second dose should be administered as soon as possible, with the second and third doses separated by at least 8 weeks 1
• The minimum interval between the first and second doses is 4 weeks, and the final dose must be administered at least 8 weeks after the second dose and at least 16 weeks after the first dose 1
• Vaccine doses administered ≤4 days before the minimum interval are considered valid 1, 2

Response to Vaccination and Revaccination

• After the first dose of hepatitis B vaccine, approximately 30-55% of healthy adults aged <40 years develop protective antibody levels 1
• After the second dose, approximately 75% develop protective antibody levels 1
• After the third dose, >90% of healthy adults aged <40 years develop protective antibody levels 1
• The response rate decreases with age, with only about 75% of persons aged 60 years developing protective antibody levels after a complete series 1

Common Pitfalls to Avoid

• Do not restart the vaccination series if the schedule is interrupted; simply continue where left off 1, 2
• Do not assume serologic testing is required before vaccination; lack of testing should not be a barrier to vaccination 2
• Do not use Heplisav-B in pregnant women, as there is insufficient data on vaccine-associated risks in pregnancy 2
• Be aware that older adults (>40 years) have lower response rates to hepatitis B vaccination and may require revaccination or higher doses 1, 4

By following these evidence-based dosing regimens, you can ensure optimal protection against hepatitis A and B infections while maximizing patient compliance through appropriate vaccine selection and scheduling.