Immunogenicity of a recombinant DNA hepatitis B vaccine in institutionalized patients with Down's syndrome

Residents of institutions for the mentally handicapped, especially Down's syndrome (DS) patients, are at increased risk for exposure to hepatitis B virus (HBV). Indeed, during a serological survey of 770 mentally retarded residents in institutions in Antwerp in 1985, 32.6% of the 92 DS patients screened were HBsAg positive, compared with 7.2% of the 678 other mentally retarded (OMR) patients. Seronegative mentally handicapped individuals from three institutions were vaccinated with 20 mu g of a recombinant yeast-derived hepatitis B vaccine (YDV) according to a 0, 1, 6 month schedule. One month after the third vaccine dose, 81.3 and 97.7% of DS and OMR patients had seroconverted, respectively, with GMTs of 516.3 and 1078.7 mIU/ml. Two years after the start of the vaccination course, 66.7 and 96% of subjects in the two groups still had protective antibody levels, although GMTs had decreased to 40.1 and 166.3 mIU/ml in the two groups, respectively. The institutionally mentally handicapped, including DS patients are capable of responding adequately to YDV.