Lack of Effect of Hepatitis B Vaccine on T-Cell Phenotypes

THE safety and efficacy of hepatitis B vaccine have been established in controlled trials.1 2 3 The vaccine consists of purified 22-nm particles of hepatitis B surface antigen derived from the plasma of chronic carriers of the surface antigen, many of whom are homosexual men4 — a group at risk of the acquired immunodeficiency syndrome (AIDS).5 Because epidemiologic observations suggest that AIDS is likely to be transmitted by a blood-borne virus,6 theoretically, an AIDS agent could contaminate the plasma pool from which hepatitis B vaccine is produced.Preparation of hepatitis B vaccine includes multiple inactivation steps (pepsin, urea, and formalin), which cumulatively . . .