Genetic susceptibility to wild and vaccine polio virus: genotypes and their frequency.

The frequency of proposed genotypes which predispose to poliomyelitis, is tabled. Susceptibility is due to a gene or linkage group of genes with a frequency of 2% for the homozygote and 24% for the heterozygote. Two subgroups are identified where a second gene might make the persons susceptible to vaccine strains of virus. Cutter vaccinees might form a third group with increased susceptibility under special circumstances. The age at which genetic susceptibility changes to phenotypic susceptibility may be modified by physical factors such as those due to congenital syphilis and Salvarsan, and thalidomide.