In reporting the preliminary data on the anti-B hepatitis vaccination study, the paper compares the two plasma-derived vaccines on the market, Pasteur Hevac-B and HB-Vax M.S.D. in two groups of hemodialyzed subjects. It briefly described the properties of the two vaccines and examines the respective vaccination protocols, doses and administration methods. After reporting the data on the two groups considered and the results in each one, the paper concludes that the M.S.D. vaccine is the most efficacious for hemodialyzed subjects.