This study, conducted in an institute for handicapped children, is part of an overall effort to extend the anti-HBV vaccine to all high risk categories. Out of 50 patients, 24 (48%) registered negative results for all HBV markers. Twenty-three of these 24 (95.8%) were vaccinated with the Hevac-B Pasteur vaccine s.c. Of 66 employees tested, 51 resulted negative for all HBV markers (77.3%). Of these, 45 (88.2%) were vaccinated: 20 with Hevac-B vaccine s.c., 25 with HBVAX vaccine i.m. via intragluteal injection. Of the 42 who completed the study with Hevac-B, 41 showed an antibody response greater than or equal to 10 mUI (serum conversion of 97.6%). Of the 25 subjects vaccinated with HBVAX, 17 showed an immunological antibody response greater than or equal to 10 mUI (serum conversion of 68%) (p less than 0.001). This differing effectiveness is probably due to the method of injection used in administering HBVAX. It should also be noted that an intense health-education program, stressing high sanitary standards, was instrumental to the project.