Systematic Veterinary Virology

VIRUS STRAINS

EEEV

• Strain VA33, Ten Broeck.

VEV

• VEE viruses are divided into six antigenic subtypes (I–VI).
• Within subtype I there are five antigenic variants (variants AB–F).
• Antigenic variants I-AB and I-C are associated with epizootic activity in equids.
• The other three variants of subtype I (I-D, I-E, I-F) and the other five subtypes of VEE have been associated with natural enzootic cycles. These variants and subtypes have been considered to be nonpathogenic for equids, although they can cause clinical disease in humans.