Hepatitis A (HepA) Vaccine
Both hepatitis A vaccines provide long-term protection against hepatitis A.
(See also Overview of Immunization.)
Hepatitis A (HepA) vaccines are prepared from formalin-inactivated, cell culture–derived hepatitis A virus. There are 2 hepatitis A vaccines (Havrix® and Vaqta®); both are available in pediatric and adult formulations.
A vaccine that combines hepatitis A and hepatitis B vaccine (Twinrix®) is also available.
The HepA vaccine is a routine childhood vaccination (see Table: Recommended Immunization Schedule for Ages 0–6 Years).
HepA vaccine also is indicated when any of the following is present:
A desire for protection from hepatitis A in people not previously vaccinated
Travel to or work in endemic areas
Occupational exposure (eg, working with primates infected with hepatitis A virus [HAV] or HAV in a research laboratory)
Sex between men
Use of illicit drugs (injected or not), such as methamphetamine
Treatment with clotting factor concentrates
A chronic liver disorder
A clotting factor disorder
Anticipated close personal contact (eg, as members of the household or as regular babysitters) with an adopted child during the first 60 days after the child's arrival in the US from an endemic area
Healthy adults ≤ 40 years who have recently been exposed to hepatitis A virus and adults > 40 if hepatitis A immunoglobulin cannot be obtained
The combination HepA and HepB vaccine can be used in people ≥ 18 years who have indications for either hepatitis A or hepatitis B vaccine and who have not been previously vaccinated with one of the vaccine components.
The main contraindication for HepA vaccine is
A severe allergic reaction (eg, anaphylaxis) after previous dose or to a vaccine component
The main precaution with HepA vaccine is
The HepA vaccine dose is 0.5 mL IM up to age 18 years or 1 mL IM for adults (age ≥ 19 years).
Children are given a 2-dose series typically at age 12 to 23 months and 6 to 18 months after the 1st dose.
Adults are given the vaccine in a 2-dose series at either 0 and 6 to 12 months (Havrix®) or 0 and 6 to 18 months (Vaqta®).
Or adults may be given the combination HepA and HepB vaccine on a 3-dose schedule: at 0, 1, and 6 months. The 1st and 2nd doses should be separated by ≥ 4 weeks, and the 2nd and 3rd doses should be separated by ≥ 5 months. Alternatively, the vaccine may be given on a 4-dose schedule: on days 0, 7, and 21 to 30, followed by a booster 12 months after the 1st dose.
As soon as an adoption of a child from an endemic area is planned, close contacts should be given the 1st dose of the 2-dose HepA vaccine series, ideally ≥ 2 weeks before the adopted child arrives.