Enhancing the efficacy and ease of application of existing endemic livestock disease vaccines via novel adjuvants and delivery systems

Control of endemic livestock diseases (ELD) is hindered by the suboptimal immunogenicity and efficacy of existing vaccines. In addition, practical issues of storage and administration on-farm can negatively impact on the efficacy of current vaccines and present barriers to the development of more efficacious vaccination strategies. We will exploit recent advances in knowledge and technologies to improve existing ELD vaccines. This includes vaccine adjuvants and formulations; delivery routes and immunisation regimes, including mucosal immunisation either alone or in combination with parenteral immunisation; and automated delivery devices. By combining these three elements, we anticipate achieving significant benefits in terms of: immune responses tailored to provide stronger protection; improved vaccine stability; needle- and error-free dosing; and cost savings through dose sparing. Using a co-design inspired approach, we will work with vaccine companies and selected producers, their veterinarians, and wider stakeholders to ensure that the research addresses their concerns and meets their needs with respect to on-farm delivery and use of vaccines. We will next use PRRS as a test case and determine whether a ‘prime and pull’ immunisation strategy combining a solid dose implant live-attenuated PRRS virus prime, and an inactivated PRRSV with mucosal adjuvant boost administered by an automated jet device can enhance protection against experimental infection. By sharing these results and demonstrating the delivery devices to stakeholders we will gain feedback to help shape further development. The proposed approach is novel by exploiting and combining recent advances in vaccine formulation and delivery to address the shortcomings of existing vaccines, including their application. This project has broad translational potential which could lead to improved vaccine/formulations for diseases of both livestock and humans.