While the world continues to respond to the COVID-19 pandemic, novel influenza viruses persist as a constant pandemic threat. The global response to COVID-19 has pushed the boundaries on what is possible for rapid pandemic response in several areas, including vaccine research, development, manufacturing, equitable distribution, allocation, and administration. If well understood and sufficiently adapted, these actions could be applied to future pandemic and seasonal influenza vaccine preparedness efforts. However, developing and delivering these more effective vaccines to meet the demand goes beyond simply technical challenges and includes issues across governance, financing, research, supply chain, and public engagement. To address these challenges, the National Academies of Sciences, Engineering, and Medicine convened a virtual public workshop in May of 2021 to discuss the emerging evidence on unprecedented actions related to COVID-19 that could inform and advance pandemic and seasonal influenza vaccine preparedness efforts and subsequent response. This Proceedings of a Workshop provides a high-level summary of the presentations and discussions that occurred during the workshop. Table of Contents Front Matter 1 Introduction 2 Global Coordination, Partnerships, and Financing 3 Vaccine Research and Development 4 Vaccine Distribution and Supply Chain 5 Research Translation and Communication 6 Final Remarks References Appendix A: Statement of Task Appendix B: COVID-19 Lessons to Inform Pandemic Influenza Response Appendix C: Biographical Sketches of Workshop Presenters