Location: Infectious Bacterial Diseases Research
Project Number: 5030-32000-232-018-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jul 1, 2022
End Date: Sep 30, 2024
1. Evaluate efficacy of orally delivered BCG vaccination of calves to protect against experimental challenge with virulent Mycobacterium Bovis (M. bovis). 2. Evaluate feasibility of orally delivered ovalbumin (OVA) as a vaccine marker in cattle and deer. 3. Evaluate efficacy of oral vaccination with BCG using alginate spheres to protect deer against experimental challenge with virulent M. bovis.
Alginate spheres will be developed by APHIS, Wildlife Service collaborators and will be tested in captive deer in Ames, Iowa before deployment in Michigan. Immune responses to the BCG vaccine will be followed and deer will be challenged with virulent M. bovis to evaluate vaccine efficacy. In a previous calf model robust responses to M. bovis tuberculin purified protein derivative (PPD) were measured in calves receiving orally administered liquid BCG and SC injected BCG, but not in calves consuming a bait containing a capsule of lyophilized BCG. This confirmed our previous findings in deer. Consequently, we are pursuing a liquid form of BCG (already shown to be effective), which will be incorporated into edible alginate spheres and placed inside a bait. Moreover, oral ovalbumin (OVA) will be tested as a potential marker of bait consumption as antibody titers to OVA are easily measured using an ELISA. BCG-vaccinated calves will be challenged with virulent M. bovis to evaluate vaccine efficacy and gamma interferon assays will be performed. This entire experiment involving 12 calves is being repeated to confirm initial findings.