Serum antibody to poliovirus in patients in a mental deficiency hospital, with particular reference to Down's syndrome.

Neutralization tests for poliovirus antibodies were carried out on 74 patients in an adult mental deficiency hospital: 37 patients with Down's syndrome and 37 non-Down's mental defectives. The distribution of antibody titres to poliovirus types 1, 2 and 3 did not differ significantly between the two groups. Most patients had antibody to at least one poliovirus type but less than a third had antibodies at a titre of 1/8 or greater to all three types. The low level of poliovirus immunity in this population may be of epidemiological importance.