Fighting the COVID-19 pandemic required vaccinations; however, ending it requires vaccination equality. The progress in vaccinations varies greatly across countries, with low- and middle-income countries having much lower vaccination rates than advanced countries. Initially, the limited vaccine supply was in part to blame for slow pace of vaccinations in low-income countries. But as the supply constraints eased toward the end of 2021, the focus has shifted to in-country distribution challenges and vaccine hesitancy. This paper quantifies the importance of various factors in driving vaccination rates across countries, including vaccine deliveries, demographic structure, health and transport infrastructure and development level. It then estimates the contribution of these factors to vaccination inequality. We show that much of the vaccination inequality in 2021-22 was driven by the lack of access to vaccines which is beyond countries’ control. And although vaccination inequality declined over time, access to vaccines remains the dominant driver of vaccination inequality.