"The first USDA approved equine leptospirosis vaccine: A university, industry, and equine clinician collaborative One Health success story"

Program

See Program (oxfordabstracts.com) [https://virtual.oxfordabstracts.com/event/public/24474/program]  

Abstract 18^th Vaccine Congress, Lisbon, Portugal, 8-11 Sep 2024

The first USDA approved equine leptospirosis vaccine: A university, industry, and equine clinician collaborative One Health success story

Also SEE:

Craig N. Carter¹, Meg N. Steinman¹, Jacqueline L. Smith¹, Erdal Erol¹ 

Gloria Gellin¹, Stuart Brown², Jacquelin Boggs³, Noah Cohen⁴

¹University of Kentucky, Veterinary Diagnostic Laboratory, Lexington, KY

² Vice President, Equine Safety, Keeneland Racecourse , Lexington, KY

³Zoetis Animal Health, Kalamazoo, MI, 

⁴Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, TX

The Bluegrass Region of central Kentucky USA hosts one of the world's most successful thoroughbred equine breeding programs. Cases captured by the University of Kentucky (UKY) Veterinary Diagnostic Laboratory (UKVDL) identified a high number of equine leptospirosis abortions (confirmed by immunofluorescence) from 1993-2012. A follow-up study revealed losses by horse farmers were estimated at over $102M US on the >400 thoroughbred farms surrounding Lexington, Kentucky in the 20-year period. Although licensed vaccines were available at the time for dogs, pigs, and cattle, no approved vaccine existed for the horse. The UKY Department of Veterinary Science conducted a national sero-epidemiology study to establish a baseline for horses at risk for leptospirosis exposure. A total of 1495 horses in 29 U.S. states and 1 Canadian province were MAT tested on residual serum from routine Equine Infectious Anemia testing. Of the group evaluated, 45% were positive for at least 1 of 6 serovars (Bratislava, Icterohemorrhagiae, Canicola, Grippotyphosa, Pomona, and Hardjo). Although the odds of being seropositive were greater for some breeds and some serovars, breed was not associated with seropositivity after adjusting for age, region, or both. It was concluded that equine exposure to pathogenic leptospiral organisms is likely high across North America. Zoetis Animal Health duplicated the UKY national study (n =>5000) with similar findings. This led Zoetis to pursue the development of a leptospiral vaccine for horses which was approved by the USDA and marketed in fall of 2015. A challenge study demonstrated prevention of leptospiruria and leptospiremia in the vaccinated study group.  The vaccine is commonly used in Central Kentucky and clinical cases of equine leptospirosis abortion referred to the UKVDL have declined. In 2019-2020 foaling season, there were no confirmed cases of leptospiral abortion cases received by the UKVDL for the first time in 30 years.

Note: Leptospirosis is a serious zoonotic disease.