COVID‐19 vaccine variety and dimensions of risks: What factors induced nations to introduce multiple vaccines?

Adding a new dimension to the body of research on COVID economics, this article considers the determinants of vaccine variety across nations. Driven by supply chain issues, development timelines, pricing, and vaccine nationalism, the number of available vaccines varies considerably across nations. Results show that greater pandemic severity and more populous nations had more vaccines, while nations with large land areas had fewer vaccines. Finally, while island nations were likely to have fewer vaccines, authoritarian regimes were mostly no different from other regimes. Greater COVID risks mostly lowered vaccine variety, as did supply chain issues and the prevalence of other infectious diseases. Finally, nations with worse institutional quality had more vaccines, ceteris paribus.