Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** mastitis, or inflammation of the…

Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** mastitis, or inflammation of the udder, is considered the most economically significant disease affecting dairy cattle worldwide; costing the industry an estimated $2 billion a year. The bacterium staphylococcus aureus is a main cause of mastitis that can establish subclinical infection, and result in long term reductions in milk yield. Our innovation is a subunit vaccine that can be administered to mucosal and cutaneous surfaces to induce S. Aureus-specific immunity. This vaccine uses a platform based on the enterotoxin, cholera toxin (CT). CT is a well-established immunostimulatory adjuvant that induces local and systemic immunity to block colonization and prevent disease. A2/B fusions, or chimeras, of CT (CTA2/B) are non-toxic, easily purified, and safe and immunogenic after intranasal delivery in cows. Our long term goal is to produce a cost-effective vaccine to eliminate S. Aureus mastitis in dairy cows. We hypothesize that the CTA2/B vaccine platform can be adapted to incorporate additional targeted S. Aureus antigens, and that this platform can be delivered safely to the bovine udder to induce specific immunity. For this phase I sttr we propose feasibility studies to: 1) expand and enhance vaccine protective capacity by incorporating targeted S. Aureus antigens, and 2) assess vaccine safety, immunogenicity and efficacy after intramammary vaccination in cows. Studies will support technology transfer to pentamer biologics, LLC; a small business dedicated to vaccine development in collaboration with boise state university. Studies also support the mission of USDA nifa, to advance agricultural research, and the priority area of animal production and protection.