What are the recommended hepatitis A and B vaccination schedules, indications, contraindications, and special considerations for adults?

Hepatitis Vaccination in Adults

Hepatitis B Vaccination: Preferred Regimen

For healthy adults ≥18 years, use the 2-dose Heplisav-B regimen (20 μg at 0 and 1 month) as the preferred schedule, providing faster protection with fewer clinic visits and achieving approximately 90% seroprotection. 1

Alternative Hepatitis B Schedules

• The traditional 3-dose series remains an option: Recombivax HB 10 μg or Engerix-B 20 μg administered at 0,1, and 6 months for adults ≥20 years 1
• After the first dose, only 30-55% achieve protective antibody levels; after the second dose, 75% are protected; after the third dose, >90% achieve protection 1
• Vaccine-induced immunity persists for >30 years, and routine booster doses are not needed in immunocompetent adults 1

Minimum Dosing Intervals (Critical for 3-Dose Series)

• Dose 1 to Dose 2: minimum 4 weeks 2, 3
• Dose 2 to Dose 3: minimum 8 weeks 2, 3
• Dose 1 to Dose 3: minimum 16 weeks 2, 3
• Doses given ≤4 days before the minimum interval are considered valid 2

Hepatitis A Vaccination Schedule

Administer single-antigen vaccines as a 2-dose series: Havrix at 0 and 6-12 months, or Vaqta at 0 and 6-18 months. 1

• The first dose provides substantial protection, but the second dose is essential for long-term immunity 1
• Any person seeking protection from hepatitis A virus infection should be vaccinated—identification of specific risk factors is not required 1

Combined Hepatitis A and B Vaccination (Twinrix)

Use Twinrix only when protection against both hepatitis A and B is indicated; do not use it solely for hepatitis B vaccination when hepatitis A protection is unnecessary. 2

Standard Twinrix Schedule

• Administer as a 3-dose series at 0,1, and 6 months for adults ≥18 years 1, 3

Accelerated Twinrix Schedule (for Rapid Protection)

• Four doses at 0 days, 7 days, 21-30 days, and a booster at 12 months 1, 3
• This accelerated schedule achieves 82% seroprotection for hepatitis B and 100% for hepatitis A at month 1 4
• All subjects achieve full protection by month 13 after the booster 4
• The 4-day grace period does not apply to the first three accelerated doses 3

Indications for Twinrix

• International travelers to endemic regions requiring both vaccines 2
• Men who have sex with men at risk for both infections 2
• Persons with chronic liver disease who need both vaccines 2
• Injection drug users at risk for both viruses 5

Special Populations Requiring Modified Dosing

Hemodialysis and Immunocompromised Adults

These patients require higher antigen doses (40 μg) and cannot use Heplisav-B or PreHevbrio. 2, 3

• Recombivax HB: 40 μg (1.0 mL) per dose in a 3-dose schedule at 0,1, and 6 months 3
• Engerix-B: 40 μg (2.0 mL) per dose in a 4-dose schedule at 0,1,2, and 6 months 2, 3
• Annual anti-HBs testing is recommended with booster doses when levels fall below 10 mIU/mL 2, 3

Pregnant Women

Use only Engerix-B, Recombivax HB, or Twinrix in pregnant women; do not use Heplisav-B or PreHevbrio due to insufficient safety data in pregnancy. 1, 2, 3

Healthcare Workers

All unvaccinated healthcare workers with anticipated exposure to blood or body fluids must complete a three-dose hepatitis B vaccine series at 0,1, and 6 months. 2

• Mandatory post-vaccination serologic testing: Anti-HBs testing 1-2 months after the final vaccine dose is required to confirm immunity 2
• Testing must detect a protective anti-HBs concentration of ≥10 mIU/mL 2
• Healthcare workers with anti-HBs ≥10 mIU/mL are considered immune and do not require periodic repeat testing 2

Management of Healthcare Worker Non-Responders

• If anti-HBs <10 mIU/mL after the primary series, administer a second complete three-dose series, followed by repeat anti-HBs testing 1-2 months after the third dose 2
• If anti-HBs remains <10 mIU/mL after six total doses, test for HBsAg and anti-HBc to assess infection status 2
• Confirmed non-responders after six doses should be counseled about their continued susceptibility and the need for hepatitis B immune globulin (HBIG) plus a vaccine dose for any known or likely exposure 2

Universal Recommendation

The 2022 ACIP recommends universal hepatitis B vaccination for all adults aged 19-59 years, removing the need for risk-factor screening. 3

Managing Interrupted Vaccination Schedules

If the vaccination series is interrupted, do not restart the series—simply continue where you left off. 1, 2, 3

• If interrupted after dose 1, give dose 2 as soon as possible, then dose 3 at least 8 weeks after dose 2 2
• Increasing the interval between doses has little effect on final immunogenicity 2
• There is no maximum interval between doses 1

Pre- and Post-Vaccination Testing

Pre-vaccination serologic testing is not required and should not be a barrier to vaccination in healthy adults. 1, 3

Post-vaccination testing for hepatitis B is not routinely needed in healthy immunocompetent adults, as >90% achieve protective antibody levels after completing the series. 1

• Post-vaccination testing is mandatory only for healthcare workers and other high-risk populations 2

Contraindications

• Severe allergic reaction to a previous dose or vaccine component 1
• Heplisav-B and PreHevbrio are contraindicated in pregnant women, hemodialysis patients, and children due to insufficient safety data 1, 2, 3

Common Pitfalls to Avoid

• Never restart the series if interrupted—this wastes doses and delays protection 1, 2, 3
• Do not give the third hepatitis B dose before 16 weeks from the first dose, even if 8 weeks have passed since the second dose 2, 3
• Do not use standard adult doses in hemodialysis patients—they require 40 μg doses 2, 3
• Do not use Twinrix simply for hepatitis B vaccination when the patient has no indication for hepatitis A protection 2
• Do not assume serologic testing is required before vaccination—lack of testing should not be a barrier 3
• Older adults (>40 years) have lower response rates to hepatitis B vaccination, with only about 75% of persons aged 60 years developing protective antibody levels after a complete series 3