Antigenic and genetic analyses of foot-and-mouth disease virus type A isolates for selection of candidate vaccine strain reveals emergence of a variant virus that is responsible for most recent outbreaks in India.

Recent reports indicated presence of two antigenic and genetic groups (genotypes VI and VII) of foot-and-mouth disease virus (FMDV) type A in India and are divergent from the vaccine strains. In order to choose suitable field isolate as candidate vaccine strain, anti-sera against representative isolates from both the genotypes and two in-use vaccine strains are tested in neutralization assay. Two candidate vaccine strains from both the genotypes are selected with close antigenic match to the field isolates.