What is the recommended vaccination schedule for a patient requesting Hepatitis A and Hepatitis B vaccines?

Hepatitis A and B Vaccination Schedule

For adults requesting both hepatitis A and hepatitis B vaccines, administer the combination vaccine Twinrix as a 3-dose series at 0,1, and 6 months, or use separate monovalent vaccines with hepatitis A given at 0 and 6-12 months and hepatitis B given at 0,1, and 6 months. 1

Standard Vaccination Schedules

Hepatitis B Vaccine Options

For adults ≥18 years, three evidence-based schedules are available:

• Standard 3-dose schedule: Administer at 0,1, and 6 months, which achieves >90% seroprotection in healthy adults under 40 years 1
• Heplisav-B (2-dose schedule): Administer at 0 and 1 month, achieving approximately 90% protective antibody response with greater convenience 2
• Accelerated schedule (when rapid protection needed): Administer at days 0,7, and 21-30, followed by a booster at 12 months, providing 65% seroprotection by day 28 and 99% by month 13 1, 3

Hepatitis A Vaccine Options

Two monovalent vaccines are available with similar efficacy:

• Havrix: Administer 1.0 mL (1440 ELISA units) at 0 and 6-12 months 1, 4
• Vaqta: Administer 1.0 mL (50 units) at 0 and 6-18 months 1, 4
• Both vaccines achieve >95% seroconversion rates in healthy adults 4

Combination Vaccine (Twinrix)

For patients requiring both vaccines, Twinrix offers simplified administration:

• Standard schedule: 3 doses at 0,1, and 6 months 1, 2
• Accelerated schedule: 4 doses on days 0,7, and 21-30, followed by a booster at 12 months 1, 3
• This approach reduces the number of injections from 5-6 (if using separate vaccines) to 3-4 doses 3

Critical Timing Considerations

Minimum intervals must be respected to ensure adequate immune response:

• Between first and second hepatitis B doses: 4 weeks minimum 5, 2
• Between second and third hepatitis B doses: 8 weeks minimum 5, 2
• Between first and third hepatitis B doses: 16 weeks minimum 5, 2

The interval between doses significantly impacts antibody response: A third hepatitis B dose given at 12 months produces geometric mean titers of 19,912 IU/L compared to only 5,846 IU/L when given at 6 months, demonstrating superior long-term protection with longer intervals 6

Managing Interrupted Schedules

If vaccination is interrupted, never restart the series—simply continue where you left off:

• Administer the next dose as soon as possible 7, 2
• The immune system maintains memory of previous doses even with extended intervals 7
• This applies to all hepatitis B vaccine formulations including Heplisav-B 7

Post-Vaccination Testing

Serologic testing is NOT routinely required for immunocompetent adults, but IS recommended for specific high-risk groups 1-2 months after series completion:

• Healthcare personnel 1, 5
• Hemodialysis patients 1, 5
• HIV-infected persons 1, 5
• Other immunocompromised individuals 1, 5
• Sexual partners of HBsAg-positive persons 1

An anti-HBs level ≥10 mIU/mL indicates adequate protection 1, 5

Special Population Considerations

Patients with Chronic Liver Disease

Hepatitis A vaccination is particularly important for patients with any chronic liver disease:

• Acute HAV superinfection in patients with chronic HBV or HCV causes more severe disease, acute hepatic failure, and higher fatality rates 8
• Coinfection with hepatitis A in HBV carriers increases mortality risk by 5.6- to 29-fold 1
• Vaccinate early upon diagnosis, as response decreases with disease progression 8

Hemodialysis and Immunocompromised Patients

These patients require higher doses and special monitoring:

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

Age-Related Considerations

Vaccine response decreases significantly with age:

• Adults <40 years: >90% develop protective antibodies after complete series 2
• Adults ≥60 years: Only ~75% develop protective antibodies 2
• Older adults may require revaccination or higher doses 2

Common Pitfalls to Avoid

• Do not restart the series if interrupted—this wastes doses and delays protection 7, 2
• Do not delay vaccination waiting for serologic testing—lack of testing should never be a barrier to vaccination 1, 2
• Do not assume all adults respond equally—older adults and immunocompromised patients have significantly lower response rates 2
• Do not forget hepatitis A vaccination in patients with chronic liver disease—this is a critical missed opportunity to prevent severe complications 1, 8

Prevaccination Testing

Testing before vaccination is cost-effective only in high-prevalence populations:

• Household, sexual, or needle-sharing contacts of HBsAg-positive persons 1
• HIV-positive persons 1
• Past or current injection drug users 1
• Men who have sex with men 1
• Persons with elevated liver enzymes of unknown etiology 1

When testing is performed, check HBsAg, anti-HBs, and anti-HBc, but administer the first vaccine dose immediately after blood collection without waiting for results 1