Voysey M, Clemens SAC, Madhi SA, Weckx LY, et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet 2020 Dec 8. pii: S0140-6736(20)32661.
PMID: 33306989