Vaccines for hepatitis A and B. The latest recommendations on safe and extended protection.

Hepatitis A vaccines (Havrix and Vaqta), administered in two doses, provide long-term protection. Target groups include international travelers, children in high-risk communities, homosexually active men, injecting drug users, persons who work with nonhuman primates, patients with chronic hepatitis, and recipients of clotting factors. The place of hepatitis A vaccination in the childhood-immunization schedule has not been determined. Postexposure prophylaxis for hepatitis A consists of administration of immune globulin within 2 weeks of exposure. Hepatitis B vaccines (Recombivax HB and Engerix-B), administered in three doses, provide protective antibody levels in more than 95% of recipients. Duration of protection appears to approach 10 years. Booster doses are not currently recommended. Hepatitis B vaccination has been incorporated into the routine childhood-immunization schedule. Additional target groups include medical personnel exposed to blood products, household and sexual contacts of infected persons, injecting drug users, and homosexually active men. Postexposure prophylaxis consists of administration of hepatitis B immune globulin as soon after exposure as possible, along with the initial dose of vaccine if desired.