Martins-Filho, P.R., Rocha Santana, R.R., Santos, V.S. and Barberia, L.G. 2022. Poorer and more densely populated regions have lower vaccination capability against COVID-19. EXCLI Journal. 21, (Mar. 2022), 621–622. DOI:https://doi.org/10.17179/excli2022-4798.