HEPATITIS-B VIRUS-INFECTION, HEPATITIS-B VACCINE, AND HEPATITIS-B IMMUNE GLOBULIN

Hepatitis B virus (HBV) infection is a major health problem in the Uni ted States; in 1995, approximately 128,000 cases occurred. Transmissio n of HBV occurs primarily by blood exchange (ey, by shared needles dur ing injection drug use) and by sexual contact, Persons infected early in life are much more likely to become chronically infected than those infected during adulthood: as many as 90% of infants infected perinat ally develop chronic infection and up to 25% will die of HBV-related c hronic liver disease as adults. Clinical signs of acute hepatitis occu r in about 50% of infected adults but in only 5% of infected preschool -aged children. In the United States, hepatitis B vaccine is currently made by recombinant DNA technology using baker's yeast, Preexposure v accination results in protective antibody levels in almost all infants and children (>95%) and healthy adults younger than 40 years of age ( >90%). The most common adverse event following administration of hepat itis B vaccine is pain at the injection site, which occurs in 13% to 2 9% of adults and 3% to 9% of children. A comprehensive hepatitis B vac cination policy is now recommended that includes (1) routine infant va ccination; (2) catch-up vaccination of 11- to 12-year-olds who were no t previously vaccinated; (3) catch-up vaccination of young children at high risk for infection; (4) vaccination of adolescents and adults ba sed on lifestyle or environmental, medical, and occupational situation s that place them at risk; and (5) prevention of perinatal HBV infecti on.