Viral hepatitis, type B. Studies on natural history and prevention re-examined.

Frozen serial serum specimens obtained from past studies on the natural history and prevention of Type B hepatitis in children were retested by radioimmunoassay for the following markers of hepatitis B infection: hepatitis B surface antigen (HBsAg) and antibody (anti-HBs), hepatitis B e antigen (HBeAg) and antibody (anti-HBe), and antibody to hepatitis B core antigen (anti-HBc). The interval between exposure and evidence of viremia (HBsAg) was as short as six days. HBsAg and HBeAg persisted for two to five months and occasionally for more than one year after recovery. After the disappearance of their respective antigens, anti-HBc and anti-HBs persisted for more than seven years and anti-HBe for one to two years. Treatment with hepatitis B immune globulin after exposure induced complete or partial protection or prolongation of the incubation period. Administration of heat-inactivated hepatitis B virus, MS-2 strain, to 29 children induced an inapparent infection in three, characterized by a transient appearance of HBsAg and HBeAg, and the persistence of anti-HBc, anti-HBe and anti-HBs for more than two years.