Strategy for vaccination against hepatitis B in areas with high endemicity: focus on Korea.

Hepatitis B vaccination strategies may vary from country to country depending on hepatitis B virus (HBV) endemicity, predominant modes of infection, age of infection, and health care resources. In areas with high endemicity like Korea, transmission of virus from carrier mothers to infants during the perinatal period, and from other horizontal sources to infants and children, account for most cases of HBV infection. The consequences of HBV infection at an early age are serious, as more than 70% remain chronic carriers of the virus. These chronic carriers are the principal source of infection for other susceptible people, and are themselves at high risk of developing other serious diseases, such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Theoretically, therefore, routine infant immunisation supplemented with prenatal screening of pregnant women for HBsAg or HBeAg and mass immunisation of children is the appropriate strategy for control of hepatitis B in these countries. To prevent primary liver cancer associated with HBV infection, however, immunisation of adults at high risk would also be prudent. Mandatory vaccination of all neonates is recommended in highly endemic areas, together with hepatitis B immune globulin in babies born to HBsAg carrier mothers.