Public health control of hepatitis A: memorandum from a WHO meeting.

Hepatitis A virus infection is a significant cause of morbidity in many parts of the world, and hepatitis A vaccines will be important tools for its prevention and control. This Memorandum reviews the basic features of the disease and its epidemiology, and considers the measures which are available for control and prevention, including hepatitis A vaccine. The use of this vaccine should be adapted to specific epidemiological circumstances existing within a geographical region, with special attention to the cost-effectiveness of immunization programmes.