Characterization of strains of type 3 poliovirus by oligonucleotide mapping.

T1 RNase oligonucleotide maps of RNA prepared from type 3 poliovirus were shown to be highly characteristic of the strain from which they were prepared. Strains isolated from paralytic cases of poliomyelitis temporally associated with live poliovirus vaccination were shown to be very closely related to the Sabin vaccine strain. Comparison of strains isolated in 1962, and strains isolated between 1973 and 1975 indicated that strains derived from the Sabin vaccine strain have displaced other circulating strains of type 3 poliovirus in the U.K. as a result of the use of live polio vaccine.