Immunological response of dairy cattle housed at an Ontario animal exhibit to vaccination with Escherichia coli O157 type III secreted proteins

Interventions to reduce on-farm risk are important to help decrease the likelihood that the public will come into contact with Escherichia coli O157. Dairy cattle housed at an Ontario animal exhibit were immunized against E. coli O157, and their blood was tested to measure antibody titers to type III secretory proteins in the vaccine. Data collected during this retrospective study supports the conclusions that all animals, including young calves, immunologically responded to vaccination. At the end of a nine-month study period, those animals which received a two-dose vaccination protocol had similar antibody titers to the type III secretory proteins as those administered a three-dose protocol, and all animals immunologically responded to a single annual booster dose of vaccine.