Lancet (London, England) Voysey, M, Clemens, S A C, Madhi, S A, Weckx, L Y, Folegatti, P M, Aley, P K, Angus, B, Baillie, V L, Barnabas, S L, Bhorat, Q E, Bibi, S, Briner, C, Cicconi, P, Collins, A M, Colin-Jones, R, Cutland, C L, Darton, T C, Dheda, K, Duncan, C J A, Emary, K R W, Ewer, K J, Fairlie, L, Faust, S N, Feng, S, Ferreira, D M, Finn, A, Goodman, A L, Green, C M, Green, C A, Heath, P T, Hill, C, Hill, H, Hirsch, I, Hodgson, S H C, Izu, A, Jackson, S, Jenkin, D, Joe, C C D, Kerridge, S, Koen, A, Kwatra, G, Lazarus, R, Lawrie, A M, Lelliott, A, Libri, V, Lillie, P J, Mallory, R, Mendes, A V A, Milan, E P, Minassian, A M, McGregor, A, Morrison, H, Mujadidi, Y F, Nana, A, O'Reilly, P J, Padayachee, S D, Pittella, A, Plested, E, Pollock, K M, Ramasamy, M N, Rhead, S, Schwarzbold, A V, Singh, N, Smith, A, Song, R, Snape, M D, Sprinz, E, Sutherland, R K, Tarrant, R, Thomson, E C, Török, M E, Toshner, M, Turner, D P J, Vekemans, J, Villafana, T L, Watson, M E E, Williams, C J, Douglas, A D, Hill, A V S, Lambe, T & Gilbert, S C & Pollard, A J 2021, ' 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 ', The Lancet, vol. 397, no. 10269, pp. 99-111 . https://doi.org/10.1016/S0140-6736(20)32661-1 The Lancet Voysey, M, Clemens, S A C, Madhi, S A, Weckx, L Y, Folegatti, P M, Aley, P K, Angus, B, Baillie, V L, Barnabas, S L, Bhorat, Q E, Bibi, S, Briner, C, Cicconi, P, Collins, A M, Colin-Jones, R, Cutland, C L, Darton, T C, Dheda, K, Duncan, C J A, Emary, K R W, Ewer, K J, Fairlie, L, Faust, S N, Feng, S, Ferreira, D M, Finn, A, Goodman, A L, Green, C M, Green, C A, Heath, P T, Hill, C, Hill, H, Hirsch, I, Hodgson, S H C, Izu, A, Jackson, S, Jenkin, D, Joe, C C D, Kerridge, S, Koen, A, Kwatra, G, Lazarus, R, Lawrie, A M, Lelliott, A, Libri, V, Lillie, P J, Mallory, R, Smith, A, Pollard, A J, Hyams, C & Abeysekera, K W M 2021, ' 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, vol. 397, no. 10269, pp. 99-111 . https://doi.org/10.1016/S0140-6736(20)32661-1, https://doi.org/10.1016/s0140-6736(20)32661-1 Virologica Sinica