1. Aetna considers hepatitis A vaccine a medically necessary preventive service according to the recommendations of the Centers for Disease Control's (CDC) Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics (AAP) for the following at-risk groups subject to the benefit design of the member's plan:

   1. Ethnic and geographic populations with high endemic rates or periodic outbreaks of hepatitis A infection, such as Native Americans and Alaskan Natives
   2. Homosexual and bisexual men
   3. Injection and illicit drug users
   4. Individuals with chronic liver disease
   5. Hemophiliacs
   6. Children 12 - 23 months of age. Children who are not vaccinated by age of 2 years can be vaccinated at subsequent visits.
   7. Migrant Hispanics.
   8. Travelers to areas where hepatitis A is endemic*
   9. Military personnel*
   10. Individuals with occupational risk of exposure, such as child-care and institutional workers, as well as primate-animal handlers*
   11. Laboratory workers who handle live hepatitis A virus*.

   * Note: Most Aetna HMO plans exclude coverage of immunizations required for travel or work. Please check benefit plan descriptions for details.

2. Aetna considers hepatitis A vaccine medically necessary for prophylaxis when initiated within 2 weeks after hepatitis A exposure.

Hepatitis A vaccine is approved for people 12 months of age and older and is given in a 2-dose schedule at least six months apart (AAP, 2003). Currently licensed vaccines (Havrix and Vaqta)  are given intramuscularly.

A combination hepatitis A/hepatitis B vaccine (Twinrix, GlaxoSmithKline Biologicals, Rixensart, Belgium) is approved for people 18 years of age and older and is given in a 3-dose schedule (0, 1, and 6 months) or an accelerated 4-dose schedule (0, 7, and 21-30 days, and a fourth dose at 1 year). The first three doses of the four-dose schedule are intended to provide protection equivalent to the first two doses of the original schedule. The new schedule is useful if travel or potential exposure is expected before the second dose (at 1 month) on the original schedule.

The annual recommended childhood and adolescent immunization schedule for January-December 2006 approved by the American Academy of Pediatrics, the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention, and the American Academy of Family Physicians (Fiore et al, 2006) recommends universal administration to all children at 1 year (12 to 23 months) of age. Furthermore, the 2 doses in the series should be separated by at least 6 months. Children who are not vaccinated by age 2 years can be vaccinated at subsequent visits to their pediatricians.

Either vaccine can be used for either dose, but use of the same vaccine for both doses is preferable. The recommended dose interval is 6 to 18 months for Vaqta and 6 to 12 months for Havrix.

The American Academy of Pediatrics (AAP) recommends that regions with immunization programs for 2- to 18-year-old children should continue them and expand them to include 12- to 23-month-olds. In areas without existing hepatitis A immunization programs, catch-up immunization of unvaccinated 2- to 18-year-old children should be considered. In addition, previously unvaccinated children who will be living in, or traveling to, areas with intermediate or high hepatitis A endemicity should be immunized before departure.

Immunization is especially recommended for adolescent and adult males who have sex with males, users of injectable or noninjectable illicit drugs, recipients of clotting factors, and individuals who work with hepatitis A virus in the laboratory setting.

The AAP recommends vaccinating children with immunocompromising conditions, as the vaccines do not contain living organisms. Hypersensitivity to vaccine components such as aluminum hydroxide and phenoxyethanol are contraindications to use of hepatitis A vaccines. Hepatitis A vaccine may be coadministered with other vaccines in the childhood immunization series.

The Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) has changed its guidelines for postexposure prophylaxis, recommending vaccine for healthy individuals between the ages of 1 and 40 years (CDC, 2007). Persons who have recently been exposed to hepatitis A virus and who have not been vaccinated previously should be administered a single dose of single-antigen hepatitis A vaccine or immune globulin (0.02 mL/kg) as soon as possible, within 2 weeks after exposure. All others should receive immune globulin, if possible.

The guidelines vary by age and health status (CDC, 2007). For healthy persons aged 12 months to 40 years, single-antigen hepatitis A vaccine at the age-appropriate dose is preferred to immune globulin because of vaccine’s advantages, including long-term protection and ease of administration, as well as the equivalent efficacy of vaccine to immune globulin. For persons aged more than 40 years, immune globulin is preferred because of the absence of information regarding vaccine performance in this age group and because of the more severe manifestations of hepatitis A in older adults. Vaccine can be used if immune globulin cannot be obtained. The magnitude of the risk of hepatitis A virus transmission from the exposure should be considered in decisions to use vaccine or immune globulin in this age group. For children aged less than 12 months, immunocompromised persons, persons with chronic liver disease, and persons who are allergic to the vaccine or a vaccine component, immune globulin should be used.

The ACIP recommendation is based upon evidence that  hepatitis A vaccine is as effective as immune globulin in preventing transmission. Researchers randomized 1090 susceptible household or day-care contacts of patients in Kazakhstan to prophylaxis with either hepatitis A vaccine or immune globulin within 2 weeks of exposure (Victor, et al., 2007). The investigators found that the effect of the vaccine would be similar to immune globulin. Between 2 and 8 weeks after exposure, vaccine recipients showed a 1.35 relative risk (95 percent confidence interval 0.70 to 2.67) for developing symptomatic infection as compared with those receiving immune globulin.