Vaccination rates in developing countries lag those in developed countries by a huge margin. This Research & Policy Brief identifies and quantifies the impact of six policy and regulatory actions that could increase vaccine supply to developing countries before the end of 2021. The actions focus on measures to accelerate regulatory approvals, optimize production capacity across firms, reconfigure prioritization of low-risk groups, and adjust generous dosage thresholds. Together these actions could yield enough supply to reach the interim target to vaccinate at least 40 percent of the population of every country by the end of 2021, as a means to vaccinate 60 percent of global population by mid-2022, thereby helping to end the pandemic earlier, reducing uncertainty and raising growth.