First Intranasal Equine Influenza Vaccine Introduced

After over five years of research and development, Heska Corporation is set to launch Flu Avert I.N. vaccine, the first modified-live virus, intranasal equine influenza vaccine. The proprietary vaccine and intranasal applicator will provide veterinarians with a unique and effective tool to aid in the prevention of equine influenza. The product will be available for veterinary use following USDA approval, which is expected later this year.

Most upper respiratory viral infections in horses are attributed to equine influenza, specifically A equine 2 strains. Killed virus vaccines have not proven to be as effective as once thought, even in horses vaccinated as frequently as six times a year. To address the problem, scientists and veterinarians from major universities collaborated with Heska's research team to develop and test Flu Avert I.N. vaccine.

Studies involving more than 450 horses at locations across North America have been conducted to verify both the safety and efficacy of Flu Avert I.N. vaccine. In challenge studies to test efficacy, seronegative horses were vaccinated with Flu Avert I.N. vaccine, then exposed to extremely virulent strains of the most common flu viruses, including Kentucky 98, Kentucky 91, and the Eurasian Saskatoon 90. Veterinarians then observed the horses daily for clinical signs of infection, including cough, fever, nasal discharge, poor appetites and depression. These studies have shown Flu Avert I.N. vaccine provided complete protection for 3 months and significantly reduced clinical signs for up to one year post vaccination.

“We believe the ability of Flu Avert I.N. vaccine to protect from challenge is unprecedented,” noted Dr. David Robinson, equine medical and technical consultation veterinarian for Heska Corporation. “The results are particularly impressive given that some conventional injectable flu vaccines have been known to fail within 30 days.

“We have been very pleased with Flu Avert I.N. vaccine's performance throughout testing,” said Dr. Thomas Chambers, a University of Kentucky professor and virologist. “In challenge studies, the new intranasal vaccine has been shown to be effective. Flu Avert I.N. vaccine represents a revolutionary advance in how we can deal with equine flu more effectively.”

Safe, Effective, Proven

“To my knowledge, no other equine influenza vaccine has undergone such rigorous challenge testing,” confirmed Dr. Robert Holland, a research veterinarian with the University of Kentucky. “I think it raises the standards by which all flu vaccines will be judged.”

Flu Avert I.N. vaccine has been shown to be safe as well as effective. In extensive field safety trials, only a small number of horses experienced mild post-vaccination side effects including slight nasal discharge. These signs cleared in a few days without additional treatment.

The new intranasal vaccine has several key advantages over conventional injectables. By using a cold-adapted strain, Heska has developed a modified-live virus that can only replicate at the cooler temperature of the upper respiratory system. This vaccine produces an immune response in the nasal mucosa of the horseóliterally stopping the disease process at the site of infection.

The proprietary intranasal applicator was designed with the help of equine practitioners to make veterinary administration virtually problem-free. No needles are required and vaccinating is painless. The applicator is designed to attach to a luer lock syringe and is used both for mixing the diluent with the vaccine and for administration.

During field trials, most horses accepted intranasal application without resistance. The small, 1 ml dose provides protection even if the horse snorts immediately following administration or some of the fluid drips from the nostrils.

For most horses, Heska recommends using Flu Avert I.N. vaccine on a semiannual basis. For horses at higher risk of contracting the flu due to exercise, stress, travel, competition and exposure to other horses, as well as for young horses going into training, the vaccine can be given at more frequent intervals.

In the months ahead, Heska will spearhead a program to share research with veterinarians and horse owners regarding advancements in equine influenza research. The research data regarding Heska's new intranasal modified-live virus vaccine will be presented at upcoming professional meetings and seminars.

Heska discovers, develops, manufactures and markets companion animal health products, primarily for dogs, cats and horses. Heska has a large and sophisticated scientific effort devoted to applying biotechnology to the large and growing companion animal health market. Heska also offers diagnostic and patient monitoring equipment and supplies, as well as laboratory diagnostic products in the United States and Europe to veterinarians, and operates USDA-and FDA-licensed facilities which manufacture vaccine, pharmaceutical, and allergy immunotherapy products.

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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