Foal Immune Responses after WNV Vaccination, AAEP 2008

Vaccinating 5-month-old foals with a single dose of West Nile virus chimeric vaccine in the presence of maternal antibodies to West Nile virus does induce a cell-mediated response (in the foal).

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A study conducted by personnel at the University of Kentucky and other institutions was aimed at determining an appropriate time for vaccinating foals for West Nile virus (WNV), reported David Horohov, PhD, at the 2008 American Association of Equine Practitioners Convention, which was held Dec. 6-10 in San Diego, Calif.

Among basic questions to be answered was whether maternal antibodies (that were passed to the foal via the mare’s colostrum) would interfere with stimulation of the foal’s immune response in the wake of vaccination, or whether vaccination with a WNV chimeric vaccine would stimulate a positive response. (The WNV chimeric vaccine was created by replacing the structural genes of the attenuated human yellow fever vaccine with the structural genes of WNV.) Involved in the study were 40 foals ranging in age from 3 to 5 months.



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Les Sellnow was a prolific freelance writer based near Riverton, Wyoming. He specialized in articles on equine research, and operated a ranch where he raised horses and livestock. He authored several fiction and nonfiction books, including Understanding Equine Lameness and Understanding The Young Horse. He died in 2023.

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