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

Hepatitis A Vaccination Schedule and Protocol

The recommended Hepatitis A vaccination schedule consists of a 2-dose series, with the first dose administered at 12-23 months of age and the second dose given 6-12 months later for Havrix or 6-18 months later for Vaqta. 1

Standard Vaccination Schedule by Age Group

Children (1-18 years)

• First dose at 12-23 months of age as part of routine childhood immunization 1
• Second dose:
  • Havrix (720 ELU, 0.5 mL): 6-12 months after first dose 1
  • Vaqta (25 U, 0.5 mL): 6-18 months after first dose 1

Adults (≥19 years)

• Two-dose series:
  • Havrix (1440 ELU, 1.0 mL): Initial dose followed by second dose 6-12 months later 1
  • Vaqta (50 U, 1.0 mL): Initial dose followed by second dose 6-18 months later 1
• Twinrix (combined Hepatitis A and B vaccine): 3-dose series at 0,1, and 6 months for adults ≥18 years 1

Special Populations and Considerations

Immunocompromised Persons and Those with Chronic Liver Disease

• 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, should receive one dose of vaccine plus IG (0.1-0.2 mL/kg) based on provider's risk assessment 1
• Immunocompromising conditions are not a contraindication to receiving hepatitis A vaccine 1

International Travelers

• Infants 6-11 months: One dose of HepA vaccine before departure (this dose doesn't count toward routine 2-dose series) 1
• Children and adults 12 months-40 years: Single dose of HepA vaccine as soon as travel is considered 1
• Adults >40 years, immunocompromised persons, and those with chronic liver disease traveling to high/intermediate endemic areas with <2 weeks before departure: Initial dose of HepA vaccine plus IG (0.1-0.2 mL/kg) at separate injection sites 1
• For travel duration >2 months: IG dose should be repeated every 2 months if continued protection is needed 1

Postexposure Prophylaxis (PEP)

• Should be administered within 14 days of exposure 1
• Children 12 months-40 years: One dose of HepA vaccine 1
• Adults >40 years: One dose of HepA vaccine; IG (0.1 mL/kg) may also be given based on provider's risk assessment 1
• Immunocompromised persons or those with chronic liver disease: Both HepA vaccine and IG (0.1 mL/kg) simultaneously at different anatomic sites 1

Administration Guidelines

• Administer intramuscularly with appropriate needle length based on age and size 1
• Shake vaccine well before administration; properly mixed vaccine appears as a slightly opaque, white-colored suspension 1
• If vaccination schedule is interrupted, only the required doses need to be administered (no need to restart series) 1
• Different brands of hepatitis A vaccines are interchangeable for completing the series 1

Storage Requirements

• Store between 2°C and 8°C (36°F and 46°F) 1
• Do not freeze, as freezing destroys vaccine potency 1

Important Clinical Considerations

• Seroconversion rates exceed 95% in healthy children and adults after a single dose 2
• Antibody persistence is excellent for at least 12 months after one dose, allowing flexibility in timing of the booster dose 3, 4
• For last-minute travelers, the vaccine can be administered at any time before departure as it provides significant protection even with late administration 5
• No serologic testing is recommended before or after vaccination in the general population 1