Considerations for the development of recommendations for the use of hepatitis A vaccine.

The prevention of hepatitis A virus (HAV) infection should be greatly facilitated with the expected licensure of inactivated hepatitis A vaccines. In countries with a low endemicity of infection a number of high risk groups have been identified in which HAV infection occurs, and include both children and adults. In most other countries HAV infection occurs primarily in children. Thus, selective immunization of high-risk adults or children would not be expected to lower the overall rates of infection in most countries, and the eventual objective should be the integration of hepatitis A vaccine into the routine childhood immunization schedules. This would reduce disease incidence by preventing infections in children and by preventing infections in adults that are acquired from children. The elimination of a population susceptible to HAV infection through immunization could eliminate this well-known human disease, and the epidemiology of HAV infection suggests that eradication could be attainable with effective vaccines.