For vaccination against Eastern, Western Encephalomyelitis, West Nile Virus, Influenza, Herpesvirus, and Tetanus. Vaccinating your horse is an important part of preventative health care, and no one understands horse health better than veterinarians. We strongly recommend consulting a veterinarian for all horse health care needs, including vaccinations. For those people who choose to vaccinate their horses themselves, Equi-Jec may be the right choice. Packaged in pre-filled syringes Includes a peel-off sticker for easy recordkeeping Safe for use in pregnant mares Safe for use in horses 4 months of age or older Duration of immunity 12 months for West Nile Virus