What is the recommended Hepatitis A (Hep A) vaccination schedule?

Hepatitis A Vaccination Schedule

The recommended Hepatitis A vaccination schedule is a 2-dose series, with the first dose administered at age 12 months or older and the second dose given 6-18 months after the first dose, depending on the specific vaccine used. 1

Pediatric Schedule (Ages 1-18 years)

• Havrix:

  • Dose: 720 ELU (0.5 mL)
  • Administration: Intramuscular injection
  • Schedule: 2 doses at 0 and 6-12 months 1

• Vaqta:

  • Dose: 25 U (0.5 mL)
  • Administration: Intramuscular injection
  • Schedule: 2 doses at 0 and 6-18 months 1

Adult Schedule (Ages 19 years and older)

• Havrix:

  • Dose: 1440 ELU (1.0 mL)
  • Administration: Intramuscular injection
  • Schedule: 2 doses at 0 and 6-12 months 1

• Vaqta:

  • Dose: 50 U (1.0 mL)
  • Administration: Intramuscular injection
  • Schedule: 2 doses at 0 and 6-18 months 1

• Twinrix (Combined Hepatitis A and B vaccine):

  • Dose: 720 ELU hepatitis A + 20 μg hepatitis B
  • Administration: Intramuscular injection
  • Standard schedule: 3 doses at 0,1, and 6 months 1
  • Alternative schedule: 4 doses at 0,7, and 21-30 days, with a booster at 12 months 1

Special Considerations

Interrupted Schedules

If the immunization schedule is interrupted, only the required immunization needs to be administered rather than restarting the series 1. This provides flexibility in completing the vaccination series.

High-Risk Groups

Hepatitis A vaccination is particularly important for:

• Travelers to countries with high or intermediate hepatitis A endemicity 1
• Men who have sex with men 1
• People who use injection or non-injection drugs 1
• Persons with chronic liver disease 1
• Persons with clotting factor disorders 1
• Persons working with HAV in laboratory settings 1
• Close contacts of international adoptees from endemic countries 1

Immunocompromised Patients

Immunocompromising conditions are not a contraindication to receiving hepatitis A vaccine. The preparation is an inactivated virus and has not been shown to result in increased safety risks for people with primary or secondary immunodeficiencies 1.

For patients with rheumatoid arthritis on immunosuppressive therapy (TNF inhibitors and/or methotrexate), an extra priming dose prior to travel may be considered to ensure adequate protection 2.

Vaccine Storage

The vaccine should be stored between 2°C and 8°C (36°F and 46°F). It should not be frozen as this will destroy vaccine potency 1. However, studies have shown that neither immunogenicity nor reactogenicity of Vaqta or Havrix was affected by storage at up to 37°C (98°F) for up to 1 week 1.

Vaccine Administration

Before administration, vaccine preparations should be shaken and, when well mixed, will appear as a slightly opaque, white-colored suspension 1. The vaccine should be administered intramuscularly with needle length based on age and size of the patient.

Protection Timeline

Protection is reliably present by 4 weeks after administration of the first dose of hepatitis A vaccine and may afford protection as soon as 2 weeks after immunization 1. Studies have shown seroconversion rates of 88-100% at 14-28 days after a single dose 3, 4.

The persistence of HAV antibodies has been demonstrated for at least 12 months after one dose, with excellent seroprotection rates maintained until the booster dose 4.