PROJECT SUMMARY The burden of respiratory viral diseases increases beyond the approximately 6.6 million deaths and 633 million infections globally due to COVID-19. The U.S. is now in an influenza epidemic and experiencing high respiratory syncytial virus (RSV) case rates. The rise in respiratory disease prevalence has important implications for children with asthma (which affects 1 in 12), who have increased complications from respiratory viral diseases, such as acute asthma exacerbations after an infection. Among school-aged children, elementary school students likely face greater risk due to more contact and shared surfaces. Elementary schools face unique challenges in combating the transmission of respiratory disease, which were recently amplified by the COVID-19 pandemic. Our preliminary data show that 1) school nurses lack support to implement intervention guidance during outbreaks, and 2) classrooms struggle to implement broad guidance due to instructional challenges (e.g., teaching phonics while masked). Engineering controls that do not rely on compliance (i.e., portable HEPA filters) are easier to implement and can be effective. Some of our best defenses against the spread of respiratory viruses include bundled interventions, or the “Swiss Cheese model,” where as we layer interventions, each intervention covers the “holes” (or limitations) of another. My quantitative microbial risk assessment (QMRA) models and others’ show that interventions (e.g., ventilation, masks, respirators) can reduce transmission risk. While some models exist for estimating transmission of respiratory viral infections in classrooms, they rarely incorporate real-world data regarding feasibility and are not accessible for non-modeling audiences. These models can be useful educational tools and support school nurses in risk management and decision making; updating models with real-world data, including feasibility, and making them accessible will increase their impact on public health. Through mentorship from Dr. Lynn Gerald, I propose to train in school health, survey development and implementation, and intervention testing to accomplish the following aims: SA 1: Develop risk assessment models to estimate respiratory viral infection risk reductions for bundled interventions in elementary school environments. SA 2: Create and pilot a risk decision tool for school nurses for informing intervention strategies. Developing risk decision tools for school nurses to reduce respiratory infection transmission will protect asthmatic children’s health and offer schools needed public health support. The proposed research and training will support my goal of becoming an independent researcher who uses risk assessment to advance and protect school and respiratory health.