C. S. Wiysonge, D. . Ndwandwe, L. Mathebula, A. Goga, and G. Gray, “Randomised trials of COVID-19 vaccines in Africa – charting the path forward”, S. Afr. J. Sci., vol. 118, no. 5/6, May 2022, doi: 10.17159/sajs.2022/13224.