[Response to recombinant DNA antihepatitis B vaccine in mentally retarded patients with Down's syndrome. A controlled study].

To investigate the response of mentally retarded individuals (MR) with Down's syndrome (Down-MR) to recombinant hepatitis B vaccine, three doses (20 micrograms per dose) were administered on the usual schedule (months 0, 1 and 6) to two groups of MR with mean age of 14.6 years. The first group consisted of 32 MR-Down. The second group consisted of 35 MR other etiologies (non Down-MR). Both had the same sex distribution and similar ages and weight/height index. The post vaccination anti-HBs titers were measured on months 1, 2, 6 and 8. The results could be analysed in 63 MR. Eight months after vaccination, 100% of Down-MR and 91% of non Down-MR developed a response to the vaccine (anti-HBs greater than 10 IU/l). Both groups achieved high antibody titers (geometric mean 4.298 and 6.424, respectively). A significant inverse correlation of anti-HBs with age was found, but not with sex of with the weight-height index. It was concluded that Down-MR in young age have a normal response to recombinant hepatitis B vaccine at the usual dose and schedule. Therefore, the goal to suppress the reservoir of hepatitis B in Down-MR both in institutions for MR and in normal schools should be achieved.