VACCINES AND HEPATITIS B

Abstract

On a global basis, the hepatitis B virus (HBV) is the most important vaccine-preventable liver disease. As a consequence, the development of vaccines for the prevention of HBV represents one of the major achievements of modern medicine. 34 Universal immunization against HBV has been adopted in over 80 countries. 19 Unfortunately, in many developing countries, HBV immunization coverage still is limited. The first commercially available vaccine was a plasma-derived product. Approved for use in the United States in 1981, it no longer is available in this country. However, plasma-derived vaccines currently compose 80% of worldwide HBV vaccine production. These relatively inexpensive subunit vaccines are produced by the concentration, purification, and chemical treatment of HBV surface antigen (HBsAg) particles isolated from the plasma of HBV carriers. Despite excellent immunogenicity and protective efficacy rates, 15 physician acceptance of the first plasma-derived vaccine was impeded in the United States because of unfounded concerns about the presence of bloodborne infectious agents in the vaccine. The first recombinant HBV vaccine was introduced in 1986, and a second was approved in 1989. Currently, at least 10 recombinant HBV vaccines are manufactured, but only two are approved in the United States. The current recombinant vaccines may be used interchangeably at the recommended dosage for each product. 37 Recombivax HB, the first recombinant HBV vaccine, is formulated to contain a 10-μg adult dose of HBsAg protein. Engerix-B is formulated to contain a 20-μg dose of HBsAg protein for older children and adults.