FASE Strengthening Seed - The Effect of Intra-Articular Corticosteroids on the Response to Vaccination

While vaccination remains one of the most effective strategies for preventing the spread of infectious diseases, the immune response to vaccination can be suboptimal in some populations, leading to decreased effectiveness and increased susceptibility to infection. In equids, which move intra-state/inter-state extensively and where performance, welfare, and economics are extremely important, understanding and optimizing vaccine responses are critical. Intra-articular corticosteroids (IACs) are commonly used in the management of inflammatory musculoskeletal conditions in horses. Corticosteroids generally exert their anti-inflammatory effects at the transcriptional level and are known to be immunosuppressive, while IACs have been shown to exert systemic effects. Research in immunosuppressed humans suggests an increased susceptibility to influenza and decreased efficacy of influenza vaccination. As such, the goals of this project are to evaluate the immunologic response to booster vaccination when administered concurrently with an IAC and determine whether this practice leads to reduced vaccine performance and increased susceptibility to infectious disease. These goals will be achieved through the evaluation of the serologic and cell-mediated responses to equine influenza and equine herpes virus-1 vaccination with or without IAC administration, followed by the experimental challenge with equine influenza virus. IAC treatment effects on the response to vaccines would lead to additional work determining the effect of other IACs and systemic corticosteroids on the protective effects of critical equine vaccines. Additionally, it would allow us to explore what the appropriate length of time between vaccination and IACs treatment should be in horses, an incredibly important consideration in equine medicine.