Plasma-Derived vs Recombinant Hepatitis B Vaccine

To the Editor.— A recent editorial by Hollinger 1 accompanied an article by Stevens and collegues 2 that demonstrated protective efficacy of a yeastrecombinant vaccine in preventing perinatal acquisition of hepatitis B. In comparing plasma-derived (Heptavax-B) and yeast-derived (Recombivax-HB) vaccines, the editorial raised some concerns about differences with respect to physicochemical properties and immunogenicity. Differences in physicochemical properties have been shown to be irrelevant to the utility of these vaccines in extensive clinical studies. While the hepatitis B surface antigen (HBsAg) polypeptides in yeast-derived vaccines are uniformly nonglycosylated, 70% to 80% of those in the plasma-derived vaccine are also nonglycosylated such that nonglycosylated polypeptides preponderate in both products. Reflecting this fact, antibodies induced by both vaccines have been shown to be indistinguishable in terms of affinity, avidity, and epitope specificity, particularly toward groupspecific a-epitopes; they also cross-react completely in vitro. 3 The association of HBsAg with lipids is essential for