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

Hepatitis A Vaccination Schedule and Administration

The standard Hepatitis A vaccination consists of a 2-dose series: the first dose should be given at 12-23 months of age (or when indicated in adults), followed by a second dose 6-12 months later for Havrix or 6-18 months later for Vaqta. 1

Standard Vaccination Schedule

Children

• First dose: 12-23 months of age 1
• Second dose: 6-12 months after first dose (Havrix) or 6-18 months after first dose (Vaqta) 1
• If the schedule is interrupted, simply continue with the remaining required doses—there is no need to restart the series 1
• Different brands of hepatitis A vaccines are interchangeable for completing the series 1

Adults

• Two-dose series with the same timing as children: second dose 6-12 months later for Havrix or 6-18 months later for Vaqta 1
• For Vaqta specifically: adults receive 1.0 mL (50 U) initially, then booster at 6-12 months 2
• For Havrix specifically: adults receive 1.0 mL (1440 ELISA units) initially, then 1.0 mL booster at 6-12 months 2

Administration Technique

Administer intramuscularly with appropriate needle length based on patient age and size 1:

• Shake the vaccine well before administration 1
• The vaccine should appear as a slightly opaque, white-colored suspension after proper mixing 1
• No serologic testing is recommended before or after vaccination in the general population 1

Special Populations

International Travelers

• Administer the first dose as soon as travel is considered, ideally 2 or more weeks before departure 3
• Complete the series according to the routine schedule 3
• For infants 6-11 months traveling internationally: give one dose, but this does NOT count toward the routine 2-dose series, which must still be initiated at 12 months 3

Immunocompromised Persons and Chronic Liver Disease

• These patients should receive both Hepatitis A vaccine AND immune globulin (IG) simultaneously at different anatomic sites when exposed to HAV within the past 14 days 1
• For preexposure protection in immunocompromised individuals: administer one dose of vaccine plus 0.1-0.2 mL/kg of IG based on provider's risk assessment 3

Adults Over 40 Years

• For postexposure prophylaxis: give one dose of vaccine, and consider adding IG (0.1 mL/kg) based on provider's risk assessment 3
• The provider should determine whether both vaccine and IG are warranted; if so, administer simultaneously at different anatomic sites 3

Postexposure Prophylaxis

Administer within 14 days of exposure 1:

• Ages 12 months to 40 years (healthy): one dose of vaccine only 3
• Ages >40 years (healthy): one dose of vaccine, with IG (0.1 mL/kg) added based on provider's risk assessment 3
• Immunocompromised or chronic liver disease (≥12 months): one dose of vaccine PLUS 0.1 mL/kg IG simultaneously at different sites 3
• Infants <12 months: IG only (0.1 mL/kg), no vaccine 3

A second dose is not required specifically for postexposure prophylaxis, but the vaccination series should be completed with a second dose at least 6 months after the first dose for long-term immunity 3

Combined Hepatitis A and B Vaccine (Twinrix)

If using the combined vaccine 3:

• Standard schedule: 3 doses at 0,1, and 6 months 3
• Accelerated schedule: 4 doses on days 0,7, and 21-30, followed by a booster at month 12 3
• The combined vaccine demonstrates immunogenicity at least as marked as monovalent vaccines and is generally well tolerated 4

Storage Requirements

Store between 2°C and 8°C (36°F and 46°F) 1:

• Do NOT freeze—freezing destroys vaccine potency 1

High-Risk Groups Requiring Vaccination

Vaccination is indicated for 3:

• Men who have sex with men 3
• Persons who use injection or non-injection illicit drugs 3
• Persons working with HAV-infected primates or HAV in research laboratories 3
• Persons with chronic liver disease 3
• Persons receiving clotting factor concentrates 3
• International travelers to countries with high or intermediate HAV endemicity 3
• Unvaccinated persons anticipating close contact with international adoptees from endemic countries during the first 60 days after arrival 3

Important Clinical Considerations

Common pitfall: Remember that measles, mumps, and rubella (MMR) vaccine should not be administered for at least 3 months after receipt of immune globulin 3. However, HepA vaccine and MMR can be administered simultaneously to infants aged 6-11 months traveling internationally 3.

The vaccine is highly effective, with seroconversion rates exceeding 95% in healthy children and adults 2, and hepatitis A does not cause chronic infection or chronic liver disease 5.