 The COVID-19 vaccine shortage in 2021 has limited the ability of many African nations to implement effective vaccination programs. However, even when supplies improve, it is important to consider the best time to initiate such programs. This study suggests that rolling out vaccinations earlier rather than later could be more beneficial, both in terms of health outcomes and cost-effectiveness. Additionally, the study shows that vaccination programs targeting older adults and those who have already been exposed to the virus can provide the greatest benefit. This article was authored by Yang Liu, Simon R. Proctor, Carl A. B. Pearson, and others.