1. UNHCR. https://www.unhcr.org/refugee-statistics/ (accessed 23 February 2021).
2. Collins, K. & Holder, J. https://www.nytimes.com/interactive/2021/03/31/world/global-vaccine-supply-inequity.htmlThe New York Times (31 March 2021).
3. Phelan, A. L., Eccleston-Turner, M., Rourke, M., Maleche, A. & Wang, C. Lancet 396, 800–802 (2020).
4. Berkley, S. Gavi, the Vaccine Alliance https://www.gavi.org/vaccineswork/covax-explained (2020).
5. Figueroa, J. P. et al. Lancet 397, 562–564 (2021).