This document summarizes the challenges of rapidly developing a vaccine for SARS-CoV-2 (Covid-19) during a pandemic. It discusses how previous epidemics like H1N1, Ebola, and Zika showed that vaccines often weren't available before the epidemics ended. New platforms like DNA, RNA, and recombinant protein vaccines may speed development but regulatory review and large-scale manufacturing are challenges. The pandemic requires overlapping and parallel development phases with high financial risk. Coordinated global efforts are needed to fund manufacturing at scale and establish a fair global allocation system for any successful vaccines.