Location: Animal Disease Research
Project Number: 2090-32000-040-012-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jul 16, 2019
End Date: Sep 30, 2022
There have been ongoing efforts to identify vaccine targets to protect livestock from cattle fever ticks. Vaccination with the tick gut antigen Bm86 has been shown to provide some protection, but variable effectiveness lead to poor acceptance of commercial products. However, a cooperator Bm86 vaccine is currently being used in the quarantine zone to test its utility as part of an integrated control strategy. Many studies have attempted to identify other tick antigens that might provide more consistently effective protection, however when used alone few have provided sufficient tick control. Furthermore, cattle fever ticks also transmit bovine babeosis and Bm86 alone does not directly impact transmission other than by reducing tick burden. We propose that a combination of Bm86 with additional vaccine targets would be more effective and could also include components that block transmission of B. bovis.
We have a full-length expressed vitellogenin receptor protein and conjugated peptides from the extracellular domains of aquaporin; we will combine these with the Zoetis Bm86 vaccine to simultaneously immunize cattle against all 3 gene targets. Vaccinated cattle will be infected with Babesia bovis and then will be challenged with R. microplus ticks. The expected outcome is reduced tick feeding success, reduced fecundity of those that do successfully feed and reduced B. bovis infection of larval offspring from those ticks that may survive.