Ngozi Okonjo-Iweala (GAVI) joins to explain one way to solve the complicated economic problem of how to manufacture and globally distribute a coronavirus vaccine. GAVI, CEPI and the WHO have developed the COVAX facility to pool supply and demand, reduce risk, and allow for an equitable distribution of vaccines. But to work, it will rely on trade. Will enough of the world’s vaccine manufacturing countries sign up, or will they refuse and hoard vaccines for themselves?