Abstract
Since the COVID-19 pandemic, attention and investment in pandemic preparedness have increased. Although there are many valiant plans around pandemic preparedness, they typically involve slowing the spread or mitigating the effects of a pathogen after it has already entered the human population. The task of stopping the pathogen from entering the human population in the first place, spillover prevention, remains a neglected area in discussions and planning for pandemic risk mitigation. Every spillover offers an opportunity to learn about an emerging public health threat and the conditions that aligned to enable spillover occurrence. In this article, we outline One Health approaches for use in spillover investigations, drawing from our experience investigating Hendra and Nipah virus spillovers. We present a roadmap for how findings from those investigations can lead to the development of interventions for spillover and ultimately pandemic prevention.