Strain differentiation of foot and mouth disease virus type Asia 1 isolates of Indian origin

Summary: Antigenic variation among aphthovirus type Asia 1 isolates recovered from India was investigated by a two-dimensional microneutralisation test. Two vaccine strains and three field strains were employed for reference. Considerable antigenic variation was observed among the strains. While vaccine strain Asia 1 IND 8/79 exhibited a narrow spectrum, most strains could be related to Asia 1 63/72. A broad spectrum was observed for the strain Asia 1 WBN 117/85, which has since been recommended for incorporation in the quadrivalent vaccine.