coyotes could be used as part of a vaccine trial. The problem with the Utah coyotes was that 40 of the coyotes were captive raised and had already been rabies vaccinated. Their prior vaccinations would preclude the use of a post vaccination challenge as a valid test. The coyotes were all tested for blood rabies titer levels and then offered the vaccine laced baits. The coyotes were then tested for an increase in blood titer levels at days 7, 14 and 28 following ingestion of the baits. Of the 47 coyotes in the study, 82% showed a fourfold increase in titer levels. This was truly encouraging, but the question still remained whether or not the vaccine would immunize a previously unexposed animal and then could the animal survive a challenge?The Centers for Disease Control (CDC) in Atlanta, Georgia got involved at about the same time and conducted their own study. The CDC anesthetized 12 coyotes and sprayed a dose of the oral vaccine into the back of the throats (on the tonsils) of the coyotes. The coyotes were then challenged a month later and all survived the challenge . This success, in combination with the success in Utah secured the FDA and USDA blessings for the program. It is interesting to note that this testing was being done in November, 1994 and the program was scheduled to proceed in February, 1995! If the testing came back inconclusive, officials at the Department of Health planned to go ahead with program as planned. Since the vaccine was already approved for foxes, the target animal for the p...
