The Vetera EWT + WNV vaccine is used as an aid in the prevention of diseases caused by Eastern and Western Encephalomyelitis, (EEE and WEE), tetanus, and West Nile Virus, incorporating the 2005 WNV horse isolate that protects against the strain most likely to infect horses today. Vetera vaccines are formulated using a proprietary exclusive Ultrafil™ Purification Technology, which removes most of the extraneous proteins. This makes it possible to include more antigens in a 1-mL dose and enables the horse's immune system to focus more directly on the relevant antigens. The Vetera EWT + WNV vaccine contains killed viruses and inactivated bacterin toxoid. The duration of immunity against West Nile Virus is at least 12 months. No reconstitution is necessary. For use in healthy horses as young as 4 months of age.