[Intratypical antigenic differentiation of poliovirus strains circulating in Mali by means of cross-adsorbed sera].

The intratypic antigenic differentiation of poliovirus strains isolated from sick or healthy children in Mali in 1975-1976 was performed. The method is based on the use of cross-adsorbed sera in the neutralization tests in which the virus is titrated by the plaque procedure or by the cytopathic effect. All the examined strains of serologic types I, II, and III were distinguished by the antigenic structure from the vaccine strains and were classified as "wild". Quantitative differences in the antigenic structure of type I strains isolated in different towns of Mali were found.