Horse west nile virus vaccine development

The antibody measured by the PRNT is stimulated both by vaccination and recent exposure, making this test difficult to interpret in the suspect horse. Risk of exposure and geographic distribution of West Nile virus vary from year to year with changes in distribution of insect vectors and reservoirs of the virus.

Because of the unpredictable nature of those factors and the effects of the disease, it is recommended that all horses in North America be immunized against West Nile virus.

Preventive management practices may minimize the risk of the spread and transmission of West Nile virus from infected mosquitoes. Reduction of mosquito numbers and exposure can be achieved by reducing or eliminating any stagnant or standing water in your area, removing old tires, keeping horses in the barns from dusk to dawn prime mosquito feeding times , setting out mosquito traps, keeping air moving with fans, and removing organic debris muck promptly.

Chemical controls include the use of topical anti-mosquito repellent agents approved for the horse and use of mosquito dunks in areas of standing water. Vaccination is the primary method of reducing the risk of infection from West Nile virus to the horse but clinical disease is not fully prevented. Vaccination with one of the commercially available licensed vaccines is recommended for all horses residing in those areas of North America where the disease occurs.

Of the licensed vaccines currently available, one is monovalent or multivalent inactivated and the other is a live canarypox vector vaccine. These available vaccines have been tested with a challenge model and have been proven to be effective as an aid in the prevention of viremia in experimentally infected vaccinated horses compared to nonvaccinated control horses for as long as 12 months after primary vaccination with two doses of vaccine.

Following the label instructions, primary vaccination of previously non-vaccinated horses involves administration of 2 doses of vaccine 3 to 6 weeks apart. In endemic areas, boosters are required or warranted according to local conditions conducive to disease risk.

Treatment Treatment is vital for any horse with WNV. Since there is not any specific antibody to counter attack the virus, it is important to consult your veterinarian and provide supportive therapy.

Depending upon the affect the virus has on each individual horse will determine if home or clinical care is warranted. Each animal is assessed according to it's age and health and all treatments should be under the direction of a veterinarian. Recovery times depend upon the health and age of the affected horse.

Treatment includes treating a fever if present. Ensure horse receives sufficient fluids, possibly through intravenous treatment if the horse is unable to drink on its own. Oral or intravenous feeding may also be necessary for horses unwilling to eat. For horses unable to rise slinging is recommended 2 to 3 times per day to aid in circulation and to try to prevent pressure point sores. Head and leg protection is also frequently needed.

Joint and tendon infections, sheath infections, pneumonia, and diarrhea can all occur as secondary events. Prevention Horse owners should consult their veterinarians regarding vaccination. The vaccine shots are of no value if they aren't given prior to exposure to the disease. If the horse develops WNV it is too late for the shot. The vaccines require two doses, administered three to six weeks apart, and full protection doesn't develop until four to six weeks after the second dose.

Skip to main content. University of Minnesota. Driven to Discover. Site Search. Staff Mission Contact Us. West Nile. Jul 21, Share this page:. Abstract West Nile virus WNV Flaviviridae: Flavivirus was discovered in Africa more than 80 yr ago and became recognized as an avian pathogen and a cause of neurologic disease in horses largely during periodic incursions into Europe.

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