Vaccination for Hepatitis B

Abstract

Hepatitis B virus (HBV) causes acute and chronic hepatitis, with sequelae of liver cirrhosis and hepatocellular carcinoma. HBV infection is endemic in East and Southeast Asia including Taiwan. The HBV carrier rate ranged from 15% to 20% of the general population in different areas in Taiwan before the implementation of mass hepatitis B vaccination. Since 1984, active and passive immunization with hepatitis B vaccine and hepatitis B immunoglobulin given after birth have successfully blocked vertical transmission of HBV in Taiwan. Since the implementation of mass hepatitis B vaccination for all newborns in 1986, the infection rate and carrier rate of HBV has significantly decreased over the years to levels similar to those in the United States and Western Europe. The incidence of childhood hepatocellular carcinoma has also significantly decreased. The success of the mass hepatitis B vaccination program reduced the HBV carrier pool in the community. However, certain groups still have high risks of HBV infection. Because of the serious consequences of HBV infection, and because of the safety profile of licensed hepatitis B vaccines, clinicians should attempt to identify and vaccinate persons at risk for infection. Around 5% to 10% of subjects are non-responders to standard hepatitis B vaccination. If the risk of infection is considerable, a second series of HBV vaccinations should be given. Higher doses or multiple intradermal injections may increase the responsiveness. New vaccines including some with mixed HBV proteins, or special adjuvants and DNA vaccines are under investigation.