CAN COCCIDIOSIS VACCINATION HELP RESTORE EIMERIA SENSITIVITY TO SALINOMYCIN AND OTHER IONOPHORES?
A. It can, as long as the vaccine used provides live, drug-sensitive coccidia. Research conducted by Dr. Harry D. Danforth, PhD, a USDA research microbiologist, has demonstrated that vaccinating with Coccivac-B a product containing live, drug-sensitive coccidia changes the sensitivity of coccidia on the floor of grow-out houses. More specifically, studies by Danforth showed that using this type of vaccine helped restore sensitivity to the ionophore salinomycin. When live coccidial oocysts are delivered with the vaccine, they replicate and replace drug-resistant field strains. The coccidial population in the house shifts to the more sensitive strains. Because most ionophores work the same in inhibiting coccidia, it can be extrapolated that sensitivity should be restored for other ionophores as well. Vaccination with coccidia that are not sensitive to drugs or that are salinomycin resistant would not restore sensitivity. Danforths work also shows that after vaccination with a live-oocyst
