Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 variant of concern 202012/01 (B.1.1.7): an exploratory analysis of a randomised controlled trial

doi:10.1016/S0140-6736(21)00628-0

Clinical Trial

. 2021 Apr 10;397(10282):1351-1362.

doi: 10.1016/S0140-6736(21)00628-0. Epub 2021 Mar 30.

Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 variant of concern 202012/01 (B.1.1.7): an exploratory analysis of a randomised controlled trial

Katherine R W Emary¹, Tanya Golubchik², Parvinder K Aley¹, Cristina V Ariani³, Brian Angus⁴, Sagida Bibi¹, Beth Blane⁵, David Bonsall⁶, Paola Cicconi⁴, Sue Charlton⁷, Elizabeth A Clutterbuck¹, Andrea M Collins⁸, Tony Cox⁹, Thomas C Darton¹⁰, Christina Dold¹, Alexander D Douglas⁴, Christopher J A Duncan¹¹, Katie J Ewer⁴, Amy L Flaxman⁴, Saul N Faust¹², Daniela M Ferreira⁸, Shuo Feng¹, Adam Finn¹³, Pedro M Folegatti⁴, Michelle Fuskova⁴, Eva Galiza¹⁴, Anna L Goodman¹⁵, Catherine M Green¹⁶, Christopher A Green¹⁷, Melanie Greenland¹, Bassam Hallis⁷, Paul T Heath¹⁴, Jodie Hay¹⁸, Helen C Hill⁸, Daniel Jenkin⁴, Simon Kerridge¹, Rajeka Lazarus¹⁹, Vincenzo Libri²⁰, Patrick J Lillie²¹, Catherine Ludden⁵, Natalie G Marchevsky¹, Angela M Minassian⁴, Alastair C McGregor²², Yama F Mujadidi¹, Daniel J Phillips¹, Emma Plested¹, Katrina M Pollock²³, Hannah Robinson¹, Andrew Smith²⁴, Rinn Song¹, Matthew D Snape¹, Rebecca K Sutherland²⁵, Emma C Thomson²⁶, Mark Toshner²⁷, David P J Turner²⁸, Johan Vekemans²⁹, Tonya L Villafana²⁹, Christopher J Williams³⁰, Adrian V S Hill⁴, Teresa Lambe¹, Sarah C Gilbert⁴, Merryn Voysey¹, Maheshi N Ramasamy³¹, Andrew J Pollard¹; COVID-19 Genomics UK consortium; AMPHEUS Project; Oxford COVID-19 Vaccine Trial Group

Affiliations

¹ Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK.
² Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
³ Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK.
⁴ Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
⁵ COVID-19 Genomics UK, Department of Medicine, University of Cambridge, Cambridge, UK.
⁶ Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
⁷ National Infection Service, Public Health England, Salisbury, UK.
⁸ Department of Clinical Sciences, Liverpool School of Tropical Medicine and Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK.
⁹ UK Biocentre, Milton Keynes, UK.
¹⁰ Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK; Department of Infection and Tropical Medicine, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK.
¹¹ Department of Infection and Tropical Medicine, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK; Translational and Clinical Research Institute, Immunity and Inflammation Theme, Newcastle University, Newcastle upon Tyne, UK.
¹² NIHR Southampton Clinical Research Facility and Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust; Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, UK.
¹³ University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK.
¹⁴ St George's Vaccine Institute, St George's, University of London, London, UK.
¹⁵ Department of Infection, Guy's and St Thomas' NHS Foundation Trust, St Thomas' Hospital, London, UK; MRC Clinical Trials Unit, University College London, London, UK.
¹⁶ Clinical BioManufacturing Facility, University of Oxford, Oxford, UK.
¹⁷ NIHR/Wellcome Trust Clinical Research Facility, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
¹⁸ University of Glasgow, Glasgow, UK; Lighthouse Laboratory in Glasgow, Queen Elizabeth University Hospital, Glasgow, UK.
¹⁹ Severn Pathology, North Bristol NHS Trust, Bristol, UK.
²⁰ NIHR UCLH Clinical Research Facility, London, UK; NIHR UCLH Biomedical Research Centre, London, UK.
²¹ Hull University Teaching Hospitals NHS Trust, Hull, UK.
²² London Northwest University Healthcare, Harrow, UK.
²³ NIHR Imperial Clinical Research Facility, London, UK; NIHR Imperial Biomedical Research Centre, London, UK.
²⁴ College of Medical, Veterinary & Life Sciences, Glasgow Dental Hospital and School, University of Glasgow, Glasgow, UK.
²⁵ Clinical Infection Research Group, Regional Infectious Diseases Unit, Western General Hospital, Edinburgh, UK.
²⁶ MRC University of Glasgow Centre for Virus Research, Glasgow, UK; Severn Pathology, North Bristol NHS Trust, Bristol, UK; Department of Infectious Diseases, Queen Elizabeth University Hospital, Glasgow, UK.
²⁷ Heart Lung Research Institute, Department of Medicine, University of Cambridge, Cambridge, UK; NIHR Cambridge Clinical Research Facility, Cambridge, UK; Cambridge University Hospital and Royal Papworth NHS Foundation Trusts, Cambridge, UK.
²⁸ University of Nottingham, Nottingham, UK; Nottingham University Hospitals NHS Trust, Nottingham, UK.
²⁹ AstraZeneca BioPharmaceuticals, Gaithersburg, MD, USA.
³⁰ Public Health Wales, Cardiff, UK; Aneurin Bevan University Health Board, Newport, UK.
³¹ Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK. Electronic address: maheshi.ramasamy@paediatrics.ox.ac.uk.

PMID: 33798499
PMCID: PMC8009612
DOI: 10.1016/S0140-6736(21)00628-0

Clinical Trial

Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 variant of concern 202012/01 (B.1.1.7): an exploratory analysis of a randomised controlled trial

Katherine R W Emary et al. Lancet. 2021.

. 2021 Apr 10;397(10282):1351-1362.

doi: 10.1016/S0140-6736(21)00628-0. Epub 2021 Mar 30.

Authors

Affiliations

¹ Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK.
² Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
³ Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK.
⁴ Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
⁵ COVID-19 Genomics UK, Department of Medicine, University of Cambridge, Cambridge, UK.
⁶ Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
⁷ National Infection Service, Public Health England, Salisbury, UK.
⁸ Department of Clinical Sciences, Liverpool School of Tropical Medicine and Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK.
⁹ UK Biocentre, Milton Keynes, UK.
¹⁰ Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK; Department of Infection and Tropical Medicine, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK.
¹¹ Department of Infection and Tropical Medicine, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK; Translational and Clinical Research Institute, Immunity and Inflammation Theme, Newcastle University, Newcastle upon Tyne, UK.
¹² NIHR Southampton Clinical Research Facility and Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust; Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, UK.
¹³ University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK.
¹⁴ St George's Vaccine Institute, St George's, University of London, London, UK.
¹⁵ Department of Infection, Guy's and St Thomas' NHS Foundation Trust, St Thomas' Hospital, London, UK; MRC Clinical Trials Unit, University College London, London, UK.
¹⁶ Clinical BioManufacturing Facility, University of Oxford, Oxford, UK.
¹⁷ NIHR/Wellcome Trust Clinical Research Facility, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
¹⁸ University of Glasgow, Glasgow, UK; Lighthouse Laboratory in Glasgow, Queen Elizabeth University Hospital, Glasgow, UK.
¹⁹ Severn Pathology, North Bristol NHS Trust, Bristol, UK.
²⁰ NIHR UCLH Clinical Research Facility, London, UK; NIHR UCLH Biomedical Research Centre, London, UK.
²¹ Hull University Teaching Hospitals NHS Trust, Hull, UK.
²² London Northwest University Healthcare, Harrow, UK.
²³ NIHR Imperial Clinical Research Facility, London, UK; NIHR Imperial Biomedical Research Centre, London, UK.
²⁴ College of Medical, Veterinary & Life Sciences, Glasgow Dental Hospital and School, University of Glasgow, Glasgow, UK.
²⁵ Clinical Infection Research Group, Regional Infectious Diseases Unit, Western General Hospital, Edinburgh, UK.
²⁶ MRC University of Glasgow Centre for Virus Research, Glasgow, UK; Severn Pathology, North Bristol NHS Trust, Bristol, UK; Department of Infectious Diseases, Queen Elizabeth University Hospital, Glasgow, UK.
²⁷ Heart Lung Research Institute, Department of Medicine, University of Cambridge, Cambridge, UK; NIHR Cambridge Clinical Research Facility, Cambridge, UK; Cambridge University Hospital and Royal Papworth NHS Foundation Trusts, Cambridge, UK.
²⁸ University of Nottingham, Nottingham, UK; Nottingham University Hospitals NHS Trust, Nottingham, UK.
²⁹ AstraZeneca BioPharmaceuticals, Gaithersburg, MD, USA.
³⁰ Public Health Wales, Cardiff, UK; Aneurin Bevan University Health Board, Newport, UK.
³¹ Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK. Electronic address: maheshi.ramasamy@paediatrics.ox.ac.uk.

PMID: 33798499
PMCID: PMC8009612
DOI: 10.1016/S0140-6736(21)00628-0

Abstract

Background: A new variant of SARS-CoV-2, B.1.1.7, emerged as the dominant cause of COVID-19 disease in the UK from November, 2020. We report a post-hoc analysis of the efficacy of the adenoviral vector vaccine, ChAdOx1 nCoV-19 (AZD1222), against this variant.

Methods: Volunteers (aged ≥18 years) who were enrolled in phase 2/3 vaccine efficacy studies in the UK, and who were randomly assigned (1:1) to receive ChAdOx1 nCoV-19 or a meningococcal conjugate control (MenACWY) vaccine, provided upper airway swabs on a weekly basis and also if they developed symptoms of COVID-19 disease (a cough, a fever of 37·8°C or higher, shortness of breath, anosmia, or ageusia). Swabs were tested by nucleic acid amplification test (NAAT) for SARS-CoV-2 and positive samples were sequenced through the COVID-19 Genomics UK consortium. Neutralising antibody responses were measured using a live-virus microneutralisation assay against the B.1.1.7 lineage and a canonical non-B.1.1.7 lineage (Victoria). The efficacy analysis included symptomatic COVID-19 in seronegative participants with a NAAT positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to vaccine received. Vaccine efficacy was calculated as 1 - relative risk (ChAdOx1 nCoV-19 vs MenACWY groups) derived from a robust Poisson regression model. This study is continuing and is registered with ClinicalTrials.gov, NCT04400838, and ISRCTN, 15281137.

Findings: Participants in efficacy cohorts were recruited between May 31 and Nov 13, 2020, and received booster doses between Aug 3 and Dec 30, 2020. Of 8534 participants in the primary efficacy cohort, 6636 (78%) were aged 18-55 years and 5065 (59%) were female. Between Oct 1, 2020, and Jan 14, 2021, 520 participants developed SARS-CoV-2 infection. 1466 NAAT positive nose and throat swabs were collected from these participants during the trial. Of these, 401 swabs from 311 participants were successfully sequenced. Laboratory virus neutralisation activity by vaccine-induced antibodies was lower against the B.1.1.7 variant than against the Victoria lineage (geometric mean ratio 8·9, 95% CI 7·2-11·0). Clinical vaccine efficacy against symptomatic NAAT positive infection was 70·4% (95% CI 43·6-84·5) for B.1.1.7 and 81·5% (67·9-89·4) for non-B.1.1.7 lineages.

Interpretation: ChAdOx1 nCoV-19 showed reduced neutralisation activity against the B.1.1.7 variant compared with a non-B.1.1.7 variant in vitro, but the vaccine showed efficacy against the B.1.1.7 variant of SARS-CoV-2.

Funding: UK Research and Innovation, National Institute for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midlands NIHR Clinical Research Network, and AstraZeneca.

PubMed Disclaimer

Conflict of interest statement

Declaration of interests Oxford University has entered into a partnership with AstraZeneca for further development of ChAdOx1 nCoV-19. AstraZeneca reviewed the data from the study and the final manuscript before submission but the authors retained editorial control. SCG is cofounder of Vaccitech (collaborators in the early development of this vaccine candidate) and is named as an inventor on a patent covering use of ChAdOx1-vectored vaccines (PCT/GB2012/000467) and a patent application covering this SARS-CoV-2 vaccine. TL is named as an inventor on a patent application covering this SARS-CoV-2 vaccine and was a consultant to Vaccitech. PMF is a consultant to Vaccitech. AJP is chair of the UK Department of Health and Social Care Joint Committee on Vaccination and Immunisation but does not participate in policy advice on coronavirus vaccines, and is a member of the WHO Strategic Advisory Group of Experts. AJP and SNF are NIHR senior investigators. AVSH is a cofounder of and consultant to Vaccitech and is named as an inventor on a patent covering design and use of ChAdOx1-vectored vaccines (PCT/GB2012/000467). MDS reports grants from Janssen, GlaxoSmithKline, Medimmune, Novavax, and MCM Vaccine, and grants and non-financial support from Pfizer outside of the submitted work. CMG reports personal fees from the Duke Human Vaccine Institute outside of the submitted work. ADD reports grants and personal fees from AstraZeneca outside of the submitted work. SNF reports grants from Janssen and Valneva outside of the submitted work. TLV and JV are employees of AstraZeneca. All other authors declare no competing interests.

Figures

**Figure 1**
Flow diagram of swabs included in the analysis

**Figure 2**
Consensus phylogeny of SARS-CoV-2 genomes identified in this study Clades are coloured by variant lineage and tips are coloured by vaccine allocation. Only genomes with at least 40% coverage are included (n=247). Lineages were assigned by Pangolin version 2.1.7 (lineages version 2021–02–12).

**Figure 3**
Weekly and cumulative number of B.1.1.7 and non-B.1.1.7 isolates identified in the UK trial between Oct 1, 2020, and Jan 14, 2021 Bars show overall weekly case counts (left axis) and lines show cumulative case counts (right axis).

**Figure 4**
Minimum Ct values across all NAAT positive swabs Ct values from positive NAATs performed at Lighthouse Laboratories using a ThermoFisher TaqPath three-gene assay. Each datapoint represents one participant. For each participant, the minimum of the Ct value for the N gene and ORF1ab gene was taken for each NAAT positive swab, and the minimum across all swabs for the same participant was calculated as a proxy for maximum viral load. Low Ct values are associated with a higher viral load. The midlines of the boxes show medians and the outer bounds of the boxes show IQRs. Error bars show the most extreme point within 1.5 × IQR above or below the 75th or 25th percentile. Ct=cycle threshold. NAAT=nucleic acid amplification test.

**Figure 5**
Length of the NAAT-positive period per participant Three primary symptomatic participants who received ChAdOx1 nCoV-19 remained NAAT positive for 8, 9, and 11 weeks, respectively, and one primary symptomatic participant who received the control vaccine remained NAAT positive for 11 weeks; these cases are not shown in the figure. NAAT=nucleic acid amplification test.

**Figure 6**
Live-virus microneutralisation antibody titres of sera against B.1.1.7 and a canonical non-B.1.1.7 strain (Victoria) The geometric mean titre is 58 (95% CI 44–77) for B.1.1.7 and 517 (424–631) for Victoria. The geometric mean ratio (Victoria vs B.1.1.7) is 8·9 (95% CI 7·2–11·0). The midlines of the boxes show medians and the outer bounds of the boxes show IQRs. Error bars show the most extreme point within 1·5 × IQR above or below the 75th or 25th percentile. Lines connect samples from the same participant collected at the same trial timepoint (n=49). ND₅₀=titre at which 50% virus neutralisation is achieved.

See this image and copyright information in PMC

Comment in

Pandemic moves and countermoves: vaccines and viral variants.
Sanders RW, de Jong MD. Sanders RW, et al. Lancet. 2021 Apr 10;397(10282):1326-1327. doi: 10.1016/S0140-6736(21)00730-3. Epub 2021 Mar 30. Lancet. 2021. PMID: 33798497 Free PMC article. No abstract available.

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References

1. Polack FP, Thomas SJ, Kitchin N. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med. 2020;383:2603–2615. - PMC - PubMed
1. Baden LR, El Sahly HM, Essink B. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N Engl J Med. 2021;384:403–416. - PMC - PubMed
1. Voysey M, Clemens SAC, Madhi SA. 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. 2021;397:99–111. - PMC - PubMed
1. Novavax Novavax COVID-19 vaccine demonstrates 89.3% efficacy in UK phase 3 trial. Jan 28, 2021. https://ir.novavax.com/news-releases/news-release-details/novavax-covid-...
1. Janssen Johnson & Johnson announces single-shot Janssen COVID-19 vaccine candidate met primary endpoints in interim analysis of its phase 3 ENSEMBLE trial. Jan 29, 2021. https://www.janssen.com/johnson-johnson-announces-single-shot-janssen-co...

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[1] Polack FP, Thomas SJ, Kitchin N. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med. 2020;383:2603–2615. - PMC - PubMed

[2] Polack FP, Thomas SJ, Kitchin N. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med. 2020;383:2603–2615. - PMC - PubMed

[3] Baden LR, El Sahly HM, Essink B. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N Engl J Med. 2021;384:403–416. - PMC - PubMed

[4] Baden LR, El Sahly HM, Essink B. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N Engl J Med. 2021;384:403–416. - PMC - PubMed

[5] Voysey M, Clemens SAC, Madhi SA. 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. 2021;397:99–111. - PMC - PubMed

[6] Voysey M, Clemens SAC, Madhi SA. 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. 2021;397:99–111. - PMC - PubMed

[7] Novavax Novavax COVID-19 vaccine demonstrates 89.3% efficacy in UK phase 3 trial. Jan 28, 2021. https://ir.novavax.com/news-releases/news-release-details/novavax-covid-...

[8] Novavax Novavax COVID-19 vaccine demonstrates 89.3% efficacy in UK phase 3 trial. Jan 28, 2021. https://ir.novavax.com/news-releases/news-release-details/novavax-covid-...

[9] Janssen Johnson & Johnson announces single-shot Janssen COVID-19 vaccine candidate met primary endpoints in interim analysis of its phase 3 ENSEMBLE trial. Jan 29, 2021. https://www.janssen.com/johnson-johnson-announces-single-shot-janssen-co...

[10] Janssen Johnson & Johnson announces single-shot Janssen COVID-19 vaccine candidate met primary endpoints in interim analysis of its phase 3 ENSEMBLE trial. Jan 29, 2021. https://www.janssen.com/johnson-johnson-announces-single-shot-janssen-co...

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Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 variant of concern 202012/01 (B.1.1.7): an exploratory analysis of a randomised controlled trial

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Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 variant of concern 202012/01 (B.1.1.7): an exploratory analysis of a randomised controlled trial

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