The COVID-19 pandemic demonstrated that the world was not well prepared to respond to an infectious disease threat of this magnitude. Countries across all socioeconomic and development categories have struggled to implement effective national responses. Substantial amounts of additional investment are required to support the development of country capacities to prevent, detect and respond to both existing and emerging infectious disease threats. Prior research efforts have estimated that between US$96 and $204billion is required, globally, to advance country-level health security capacities, with US$63–131billion needed over a 3-year period. Given the substantial costs of ongoing COVID-19 response, estimated to be over US$12.5trillion through 2024, and an estimated 12.1–22.7million excess deaths, globally, due to COVID-19 as of January 2022, the importance and potential return on investment of such upfront investments in capacity building are more evident than ever before.