Hepatitis A Vaccine

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Contents 1 Indications 2 Contraindications 3 Dosage 4 Pharmacokinetics 5 Notes 6 More General Terms 7 Additional Terms 8 References

Indications

• active immunization of persons >= 2 years of age against hepatitis A

• persons (including military) traveling to or working in countries where hepatitis A is endemic (including Mexico)

• >= 1 month prior to departure to endemic area [2]
• NOT needed for travel to Canada, western Europe, Australia, New Zealand, Japan [4]

• sexually active homosexual & bisexual men
• illicit drug users
• persons with chronic liver disease
• patients with clotting factor disorders [2]

• those that receive clotting factor concentrates

• persons with occupational risk

• laboratory workers who handle hepatitis A virus

• routine vaccination of children prevents outbreaks [3] & may confer herd immunity on the population [5]
• all toddlers age 12-23 months [7]

• Limitations:

• may not prevent hepatitis A infection in patients who have unrecognized hepatitis A infection at the time of vaccination
• may not prevent infection in patients who do not achieve protective antibody titers
• the lowest protective titer has not been established

Contraindications

• hypersensitivity to any component of the vaccine

• Caution:

• do not inject in gluteal region, response may be suboptimal
• shake vial or syringe well before use

• pregnancy-category C
• safety in lactation ?

Dosage

• Primary immunization:*

• Harvix:

• Children 2-18 years: 720 ELU (0.5 mL) IM in deltoid
• Adults > 18 years: 1440 ELU (1 mL) IM in deltoid

• VAQTA:

• Children 2-17 years: 25 units (0.5 mL)
• Adults >= 18 years: 50 units (1 mL)

• * 90% effective within 2-4 weeks
• Booster:

• recommended at any time between 6-12 months after primary immunization

• Injection:

• Harvix:

• 720 ELU/0.5 mL (0.5 mL vial)
• 1440 ELU/ mL (1 mL vial, 1 mL syringe)

• VAQTA:

• 25 units/0.5 mL (0.5 mL vial, 0.5 mL syringe)
• 50 units/1 mL (1 mL vial, 1 mL syringe)

Pharmacokinetics

• elimination: liver Adverse reactions:
• most common (1-10%)

• headache, fatigue, fever (rare), transient abnormal LFTs, inflammation at injection site

Notes

• may be administered concomitantly with immune globulin, although titer is likely to be lower than if vaccine is given alone
• may be administered concomitantly with hepatitis B vaccine Twinrix is combined hepatitis A/ hepatitis B vaccine

More General Terms

• vaccine

Additional Terms

• hepatitis A infection
• hepatitis A virus (HAV)

References

1. Kaiser Permanente Northern California Regional Drug Formulary, 1998
2. Medical Knowledge Self Assessment Program (MKSAP) 11, 14, American College of Physicians, Philadelphia 1998, 2006
3. Journal Watch 22(3):25, 2002 Averhoff et al JAMA 286:2968, 2001
4. Prescriber's Letter 9(7):40 2002
5. Wasley A, Samandari T, Bell BP. Incidence of hepatitis A in the United States in the era of vaccination. JAMA. 2005 Jul 13;294(2):194-201. PMID: [1]
6. Prescriber's Letter 13(2): 2006 Detail-Document#: [2] (subscription needed) [3]
7. Prescriber's Letter 14(9): 2007 Immunization Update 2007 Detail-Document#: [4] (subscription needed) [5]
8. Department of Veterans Affairs, VA National Formulary
9. Vaccinations for Hepatitis A and B [6]
10. National Guideline Clearinghouse Hepatitis A vaccine recommendations. American Academy of Pediatrics ngc-guideline: [7]

hepatitis A vaccine (Harvix, VAQTA)