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
Authors: Merryn Voysey, Sue Ann Costa Clemens, Shabir A Madhi, Lily Y Weckx, Pedro M Folegatti, Parvinder K Aley, Brian Angus, Vicky L Baillie, Shaun L Barnabas, Qasim E Bhorat, Sagida Bibi, Carmen Briner, Paola Cicconi, Andrea M Collins, Rachel Colin-Jones, Clare L Cutland, Thomas C Darton, Keertan Dheda, Christopher J A Duncan, Katherine R W Emary, Katie J Ewer, Lee Fairlie, Saul N Faust, Shuo Feng, Daniela M Ferreira, Adam Finn, Anna L Goodman, Catherine M Green, Christopher A Green, Paul T Heath, Catherine Hill, Helen Hill, Ian Hirsch, Susanne H C Hodgson, Alane Izu, Susan Jackson, Daniel Jenkin, Carina C D Joe, Simon Kerridge, Anthonet Koen, Gaurav Kwatra, Rajeka Lazarus, Alison M Lawrie, Alice Lelliott, Vincenzo Libri, Patrick J Lillie, Raburn Mallory, Ana V A Mendes, Eveline P Milan, Angela M Minassian, Alastair McGregor, Hazel Morrison, Yama F Mujadidi, Anusha Nana, Peter J O’Reilly, Sherman D Padayachee, Ana Pittella, Emma Plested, Katrina M Pollock, Maheshi N Ramasamy, Sarah Rhead, Alexandre V Schwarzbold, Nisha Singh, Andrew Smith, Rinn Song, Matthew D Snape, Eduardo Sprinz, Rebecca K Sutherland, Richard Tarrant, Emma C Thomson, M Estée Török, Mark Toshner, David P J Turner, Johan Vekemans, Tonya L Villafana, Marion E E Watson, Christopher J Williams, Alexander D Douglas, Adrian V S Hill, Teresa Lambe, Sarah C Gilbert, Andrew J Pollard, Marites Aban, Fatola Abayomi, Kushala Abeyskera, Jeremy Aboagye, Matthew Adam, Kirsty Adams, James Adamson, Yemi A. Adelaja, Gbadebo Adewetan, Syed Adlou, Khatija Ahmed, Yasmeen Akhalwaya, Saajida Akhalwaya, Andrew Alcock, Aabidah Ali, Elizabeth R. Allen, Lauren Allen, Thamires C. D. S. C Almeida, Mariana P.S. Alves, Fabio Amorim, Foteini Andritsou, Rachel Anslow, Matthew Appleby, Edward H. Arbe-Barnes, Mark P. Ariaans, Beatriz Arns, Laiana Arruda, Paula Azi, Lorena Azi, Gavin Babbage, Catherine Bailey, Kenneth F. Baker, Megan Baker, Natalie Baker, Philip Baker, Lisa Baldwin, Ioana Baleanu, Danieli Bandeira, Anna Bara, Marcella A.S. Barbosa, Debbie Barker, Gavin D. Barlow, Eleanor Barnes, Andrew S. Barr, Jordan R. Barrett, Jessica Barrett, Louise Bates, Alexander Batten, Kirsten Beadon, Emily Beales, Rebecca Beckley, Sandra Belij-Rammerstorfer, Jonathan Bell, Duncan Bellamy, Nancy Bellei, Sue Belton, Adam Berg, Laura Bermejo, Eleanor Berrie, Lisa Berry, Daniella Berzenyi, Amy Beveridge, Kevin R. Bewley, Helen Bexhell, Sutika Bhikha, Asad E. Bhorat, Zaheda E. Bhorat, Else Bijker, Geeta Birch, Sarah Birch, Adam Bird, Olivia Bird, Karen Bisnauthsing, Mustapha Bittaye, Katherine Blackstone, Luke Blackwell, Heather Bletchly, Caitlin L. Blundell, Susannah R. Blundell, Pritesh Bodalia, Bruno C. Boettger, Emma Bolam, Elena Boland, Daan Bormans, Nicola Borthwick, Francesca Bowring, Amy Boyd, Penny Bradley, Tanja Brenner, Phillip Brown, Claire Brown, Charlie Brown-O'Sullivan, Scott Bruce, Emily Brunt, Ruaridh Buchan, William Budd, Yusuf A. Bulbulia, Melanie Bull, Jamie Burbage, Hassan Burhan, Aileen Burn, Karen R. Buttigieg, Nicholas Byard, Ingrid Cabera Puig, Gloria Calderon, Anna Calvert, Susana Camara, Michelangelo Cao, Federica Cappuccini, João R. Cardoso, Melanie Carr, Miles W. Carroll, Andrew Carson-Stevens, Yasmin de M. Carvalho, José A.M. Carvalho, Helen R. Casey, Paul Cashen, Thais Castro, Lucia Carratala Castro, Katrina Cathie, Ana Cavey, José Cerbino-Neto, Jim Chadwick, David Chapman, Sue Charlton, Irina Chelysheva, Oliver Chester, Sunder Chita, Jee-Sun Cho, Liliana Cifuentes, Elizabeth Clark, Matthew Clark, Andrea Clarke, Elizabeth A. Clutterbuck, Sarah L.K. Collins, Christopher P. Conlon, Sean Connarty, Naomi Coombes, Cushla Cooper, Rachel Cooper, Lynne Cornelissen, Tumena Corrah, Catherine Cosgrove, Tony Cox, Wendy E.M. Crocker, Sarah Crosbie, Lorraine Cullen, Dan Cullen, Debora R.M.F. Cunha, Christina Cunningham, Fiona C. Cuthbertson, Suzete N. Farias Da Guarda, Larissa P. da Silva, Brad E. Damratoski, Zsofia Danos, Maria T.D.C. Dantas, Paula Darroch, Mehreen S. Datoo, Chandrabali Datta, Malika Davids, Sarah L. Davies, Hannah Davies, Elizabeth Davis, Judith Davis, John Davis, Maristela M.D. De Nobrega, Lis Moreno De Oliveira Kalid, David Dearlove, Tesfaye Demissie, Amisha Desai, Stefania Di Marco, Claudio Di Maso, Maria I.S. Dinelli, Tanya Dinesh, Claire Docksey, Christina Dold, Tao Dong, Francesca R. Donnellan, Tannyth Dos Santos, Thainá G. dos Santos, Erika Pachecho Dos Santos, Naomi Douglas, Charlotte Downing, Jonathan Drake, Rachael Drake-Brockman, Kimberley Driver, Ruth Drury, Susanna J. Dunachie, Benjamin S. Durham, Lidiana Dutra, Nicholas J.W. Easom, Samual van Eck, Mandy Edwards, Nick J. Edwards, Omar M. El Muhanna, Sean C. Elias, Mike Elmore, Marcus English, Alisgair Esmail, Yakub Moosa Essack, Eoghan Farmer, Mutjaba Farooq, Madi Farrar, Leonard Farrugia, Beverley Faulkner, Sofiya Fedosyuk, Sally Felle, Shuo Feng, Carla Ferreira Da Silva, Samantha Field, Richard Fisher, Amy Flaxman, James Fletcher, Hazel Fofie, Henry Fok, Karen J. Ford, Jamie Fowler, Pedro H.A. Fraiman, Emma Francis, Marilia M. Franco, John Frater, Marilúcia S.M. Freire, Samantha H. Fry, Sabrina Fudge, Julie Furze, Michelle Fuskova, Pablo Galian-Rubio, Eva Galiza, Harriet Garlant, Madita Gavrila, Ailsa Geddes, Karyna A. Gibbons, Ciaran Gilbride, Hardeep Gill, Sharon Glynn, Kerry Godwin, Karishma Gokani, Ursula Carvalho Goldoni, Maria Goncalves, Isabela G.S. Gonzalez, Jayne Goodwin, Amina Goondiwala, Katherine Gordon-Quayle, Giacomo Gorini, Janet Grab, Lara Gracie, Melanie Greenland, Nicola Greenwood, Johann Greffrath, Marisa M. Groenewald, Leonardo Grossi, Gaurav Gupta, Mark Hackett, Bassam Hallis, Mainga Hamaluba, Elizabeth Hamilton, Joseph Hamlyn, Daniel Hammersley, Aidan T. Hanrath, Brama Hanumunthadu, Stephanie A. Harris, Clair Harris, Tara Harris, Thomas D. Harrison, Daisy Harrison, Thomas C. Hart, Birgit Hartnell, Shadin Hassan, John Haughney, Sophia Hawkins, Jodie Hay, Ian Head, John Henry, Macarena Hermosin Herrera, David B. Hettle, Jennifer Hill, Gina Hodges, Elizea Horne, Mimi M. Hou, Catherine Houlihan, Elizabeth Howe, Nicola Howell, Jonathan Humphreys, Holly E. Humphries, Katrina Hurley, Claire Huson, Angela Hyder-Wright, Catherine Hyams, Sabina Ikram, Alka Ishwarbhai, Monica Ivan, Poppy Iveson, Vidyashankara Iyer, Frederic Jackson, Jeanne De Jager, Shameem Jaumdally, Helen Jeffers, Natasha Jesudason, Bryony Jones, Kathryn Jones, Elizabeth Jones, Christopher Jones, Marianna Rocha Jorge, Aylin Jose, Amar Joshi, Eduardo A.M.S. Júnior, Joanne Kadziola, Reshma Kailath, Faeeza Kana, Konstantinos Karampatsas, Mwila Kasanyinga, Jade Keen, Elizabeth J. Kelly, Dearbhla M. Kelly, Debbie Kelly, Sarah Kelly, David Kerr, Renato de Ávila Kfouri, Liaquat Khan, Baktash Khozoee, Sarah Kidd, Annabel Killen, Jasmin Kinch, Patrick Kinch, Lloyd D.W. King, Thomas B. King, Lucy Kingham, Paul Klenerman, Francesca Knapper, Julian C. Knight, Daniel Knott, Stanislava Koleva, Matilda Lang, Gail Lang, Colin W. Larkworthy, Jessica P.J. Larwood, Rebecca Law, Erica M. Lazarus, Amanda Leach, Emily A. Lees, Nana-Marie Lemm, Alvaro Lessa, Stephanie Leung, Yuanyuan Li, Amelia M. Lias, Kostas Liatsikos, Aline Linder, Samuel Lipworth, Shuchang Liu, Xinxue Liu, Adam Lloyd, Stephanie Lloyd, Lisa Loew, Raquel Lopez Ramon, Leandro Lora, Vicki Lowthorpe, Kleber Luz, Jonathan C. MacDonald, Gordon MacGregor, Meera Madhavan, David O. Mainwaring, Edson Makambwa, Rebecca Makinson, Mookho Malahleha, Ross Malamatsho, Garry Mallett, Kushal Mansatta, Takalani Maoko, Katlego Mapetla, Natalie G. Marchevsky, Spyridoula Marinou, Emma Marlow, Gabriela N. Marques, Paula Marriott, Richard P. Marshall, Julia L. Marshall, Flávia J. Martins, Masebole Masenya, Mduduzi Masilela, Shauna K. Masters, Moncy Mathew, Hosea Matlebjane, Kedidimetse Matshidiso, Olga Mazur, Andrea Mazzella, Hugh McCaughan, Joanne McEwan, Joanna McGlashan, Lorna McInroy, Zoe McIntyre, Daniela McLenaghan, Nicky McRobert, Steve McSwiggan, Clare Megson, Savviz Mehdipour, Wilma Meijs, Renata N.Á. Mendonça, Alexander J. Mentzer, Neginsadat Mirtorabi, Celia Mitton, Sibusiso Mnyakeni, Fiona Moghaddas, Kgaogelo Molapo, Mapule Moloi, Maria Moore, M. Isabel Moraes-Pinto, Marni Moran, Ella Morey, Róisín Morgans, Susan Morris, Sheila Morris, Helen C. Morris, Franca Morselli, Gertraud Morshead, Richard Morter, Lynelle Mottal, Andrew Moultrie, Nathifa Moya, Mushiya Mpelembue, Sibekezelo Msomi, Yvonne Mugodi, Ekta Mukhopadhyay, Jilly Muller, Alasdair Munro, Claire Munro, Sarah Murphy, Philomena Mweu, Celia Hatsuko Myasaki, Gurudutt Naik, Kush Naker, Eleni Nastouli, Abida Nazir, Bongani Ndlovu, Fabio Neffa, Cecilia Njenga, Helena Noal, Andrés Noé, Gabrielle Novaes, Fay L. Nugent, Géssika Nunes, Katie O'Brien, Daniel O'Connor, Miranda Odam, Suzette Oelofse, Blanche Oguti, Victoria Olchawski, Neil J. Oldfield, Marianne G. Oliveira, Catarina Oliveira, Angela Oosthuizen, Paula O'Reilly, Piper Osborne, David R.J. Owen, Lydia Owen, Daniel Owens, Nelly Owino, Mihaela Pacurar, Brenda V.B. Paiva, Edna M.F. Palhares, Susan Palmer, Sivapriyai Parkinson, Helena M.R.T. Parracho, Karen Parsons, Dipak Patel, Bhumika Patel, Faeezah Patel, Kelly Patel, Maia Patrick-Smith, Ruth O. Payne, Yanchun Peng, Elizabeth J. Penn, Anna Pennington, Marco Polo Peralta Alvarez, James Perring, Nicola Perry, Rubeshan Perumal, Sahir Petkar, Tricia Philip, Daniel J. Phillips, Jennifer Phillips, Mary Kgomotso Phohu, Lorinda Pickup, Sonja Pieterse, Jo Piper, Dimitra Pipini, Mary Plank, Joan Du Plessis, Samuel Pollard, Jennifer Pooley, Anil Pooran, Ian Poulton, Claire Powers, Fernando B. Presa, David A. Price, Vivien Price, Marcelo Primeira, Pamela C. Proud, Samuel Provstgaard-Morys, Sophie Pueschel, David Pulido, Sheena Quaid, Ria Rabara, Alexandra Radford, Kajal Radia, Durga Rajapaska, Thurkka Rajeswaran, Alberto San Francisco Ramos, Fernando Ramos Lopez, Tommy Rampling, Jade Rand, Helen Ratcliffe, Tom Rawlinson, David Rea, Byron Rees, Jesús Reiné, Mila Resuello-Dauti, Emilia Reyes Pabon, Carla M. Ribiero, Marivic Ricamara, Alex Richter, Neil Ritchie, Adam J. Ritchie, Alexander J. Robbins, Hannah Roberts, Ryan E. Robinson, Hannah Robinson, Talita T. Rocchetti, Beatriz Pinho Rocha, Sophie Roche, Christine Rollier, Louisa Rose, Amy L. Ross Russell, Lindie Rossouw, Simon Royal, Indra Rudiansyah, Sarah Ruiz, Stephen Saich, Claudia Sala, Jessica Sale, Ahmed M. Salman, Natalia Salvador, Stephannie Salvador, Milla Sampaio, Annette D. Samson, Amada Sanchez-Gonzalez, Helen Sanders, Katherine Sanders, Erika Santos, Mayara F.S. Santos Guerra, Iman Satti, Jack E. Saunders, Caroline Saunders, Aakifah Sayed, Ina Schim van der Loeff, Annina B. Schmid, Ella Schofield, Gavin Screaton, Samiullah Seddiqi, Rameswara R. Segireddy, Roberta Senger, Sonia Serrano, Rajiv Shah, Imam Shaik, Hannah E. Sharpe, Katherine Sharrocks, Robert Shaw, Adam Shea, Amy Shepherd, James G. Shepherd, Farah Shiham, Emad Sidhom, Sarah E. Silk, Antonio Carlos da Silva Moraes, Gilberto Silva-Junior, Laura Silva-Reyes, Anderson D. Silveira, Mariana B.V. Silveira, Jaisi Sinha, Donal T. Skelly, Daniel C. Smith, Nick Smith, Holly E. Smith, David J. Smith, Catherine C. Smith, Airanuédida Soares, Tiago Soares, Carla Solórzano, Guilherme L. Sorio, Kim Sorley, Tiffany Sosa-Rodriguez, Cinthia M.C.D.L. Souza, Bruno S.D.F. Souza, Alessandra R. Souza, Alexandra J. Spencer, Fernanda Spina, Louise Spoors, Lizzie Stafford, Imogen Stamford, Igor Starinskij, Ricardo Stein, Jill Steven, Lisa Stockdale, Lisa V. Stockwell, Louise H. Strickland, Arabella C. Stuart, Ann Sturdy, Natalina Sutton, Anna Szigeti, Abdessamad Tahiri-Alaoui, Rachel Tanner, Carol Taoushanis, Alexander W. Tarr, Keja Taylor, Ursula Taylor, Iona Jennifer Taylor, Justin Taylor, Rebecca te Water Naude, Yrene Themistocleous, Andreas Themistocleous, Merin Thomas, Kelly Thomas, Tonia M. Thomas, Asha Thombrayil, Fawziyah Thompson, Amber Thompson, Kevin Thompson, Ameeka Thompson, Julia Thomson, Viv Thornton-Jones, Patrick J. Tighe, Lygia Accioly Tinoco, Gerlynn Tiongson, Bonolo Tladinyane, Michele Tomasicchio, Adriana Tomic, Susan Tonks, James Towner, Nguyen Tran, Julia Tree, Gerry Trillana, Charlotte Trinham, Rose Trivett, Adam Truby, Betty Lebogang Tsheko, Aadil Turabi, Richard Turner, Cheryl Turner, Marta Ulaszewska, Benjamin R. Underwood, Rachel Varughese, Dennis Verbart, Marije Verheul, Iason Vichos, Taiane Vieira, Claire S. Waddington, Laura Walker, Erica Wallis, Matthew Wand, Deborah Warbick, Theresa Wardell, George Warimwe, Sarah C. Warren, Bridget Watkins, Ekaterina Watson, Stewart Webb, Alice Webb-Bridges, Angela Webster, Jessica Welch, Jeanette Wells, Alison West, Caroline White, Rachel White, Paul Williams, Rachel L. Williams, Rebecca Winslow, Mark Woodyer, Andrew T. Worth, Danny Wright, Marzena Wroblewska, Andy Yao, Rafael Zimmer, Dalila Zizi, Peter Zuidewind
Journal: The Lancet (2020)

SummaryBackgroundA safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials.MethodsThis analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674.FindingsBetween April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation.InterpretationChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials.FundingUK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca.