Newly Licensed Hepatitis B Vaccine

Abstract

THE RECENTLY licensed subunit hepatitis B vaccine (HEPATAVAX-B) is unique among vaccines in that it is manufactured solely from human plasma obtained from asymptomatic individuals with chronic hepatitis B. Plasma from donors selected for manufacturing this vaccine contains high concentrations of noninfectious hepatitis B surface antigen (HBsAg) particles and lower concentrations of infectious hepatitis B virus (HBV). The ratio of HBsAg to HBV can be as great as 10,000:1.¹From the starting plasma, 22-nm spherical HBsAg particles are separated from HBV by ultracentrifugation. The 22-nm particles are then further purified by digestion with pepsin followed by the addition of 8M urea. Finally, the vaccine is treated with formaldehyde. Vaccine Plasma Donors Vaccine plasma donors are selected for their high titers of HBsAg. By federal regulation, they must be asymptomatic and in apparent good health.²They must meet all federal requirements for acceptable plasmapheresis donors, except that their serum