PRESTIGE(R) 5 + WNV has been shown to be effective for the vaccination of healthy horses 6 months of age or older against Eastern and Western encephalomyelitis viruses (EEE/WEE), equine influenza virus (EIV), equine herpesvirus types 1 and 4 (EHV-1, and EHV-4), tetanus and West Nile Virus. | Merck Prestige 5 + WNV Equine Vaccine | Size Single Dose