A CGD Working Paper with Amanda Glassman and George Yang. At the start of 2022, profound inequities in the pace of access to COVID-19 vaccines and the level of coverage of COVID-19 vaccination remain, especially with regard to the world’s poorest countries. Yet despite this inequity, we find that global COVID-19 vaccine development and diffusion has been the most rapid in history, and this rapid scale-up is evident not only in high-income countries but also in upper- and lower-middle-income countries, home to the majority of the world’s population. This paper explores the historical record in the development and deployment of vaccines globally and puts the COVID-19 vaccine rollout in that context. Although far more can be done and should be done to speed equitable access to vaccines in the COVID-19 response, it is worth noting the revolutionary speed of both the vaccine development and the diffusion process, and the potential good news that this signals for the future of pandemic preparedness and response.