Localization of four antigenic sites involved in Venezuelan equine encephalomyelitis virus protection.

Stable neutralization and protection escape variants of a virulent strain (Trinidad Donkey) of the VEE virus were selected by monoclonal antibodies (MAbs). Determination of nucleotide sequences of nine variants revealed a clustering of single mutations in four regions of the E1 and E2 glycoproteins. Involvement of amino acid residues 206 (site E1-1), 57 and 59 (site E2-2), 180, 182, 213, 214 and 216 (site E2-6) and 232 (site E2-3) in protective epitopes was demonstrated.