Many months after COVID-19 vaccines were first authorized for public use, still limited supplies could only partially reduce the devastating loss of life and economic costs caused by the pandemic. Could additional vaccine doses have been manufactured more quickly some other way? Would alternative policy choices have made a difference? This paper provides a simple analytical framework through which to view the contours of the vaccine value chain. It then creates a new database that maps the COVID-19 vaccines of Pfizer/BioNTech, Moderna, AstraZeneca/Oxford, Johnson & Johnson, Novavax, and CureVac to the product- and location-specific manufacturing supply chains that emerged in 2020 and 2021. It describes the choppy process through which dozens of other companies at nearly 100 geographically distributed facilities came together to scale up global manufacturing. The paper catalogues major pandemic policy initiatives―such as the United States‘ Operation Warp Speed―that are likely to have affected the timing and formation of those vaccine supply chains. Given the data, a final section identifies further questions for researchers and policymakers.