Efficacy of the AZD1222 (ChAdOx1 nCoV-19) COVID-19 Vaccine Against SARS-CoV-2 Variants of Concern

In this South African phase 1/2b study, we demonstrated vaccine efficacy (VE) of two doses of AZD1222 for asymptomatic and symptomatic SARS-CoV-2 infection: 90.6% against wild-type and 77.1% against the Delta variant ≥9 months after vaccination. VE against infection with the Beta variant, which preceded circulation of Delta, was 6.7%. Clinical trial identifier [CT.gov][1] [NCT04444674][2] ### Competing Interest Statement C.L.C. receives consulting fees from Pfizer, Merck Sharp & Dohme and Biovac, and institutional research grants from the Bill & Melinda Gates Foundation, GIZ and Sanofi. Q.E.B receives institutional research grants from Wits Health Consortium, Regeneron Pharmaceuticals, GlaxoSmithKline, Avillion, Sanofi, grants NovoNordisk, Bill & Melinda Gates Foundation, the South African Medical Research Council, Novavax, AstraZeneca, and Clover BioPharmaceuticals. T.L. is a named inventor on a pending patent application for ChAdOx1 nCoV-19 and was a consultant to Vaccitech. S.C.G. is a named inventor on a patent covering use of ChAdOx1 as a vaccine vector, and a second covering ChAdOx1 nCoV-19. A.J.P. serves as an advisor to the UK Joint Committee on Vaccines and Immunization but is not involved in its COVID19 committee and receives grants from NIHR on COVID vaccines and institutional support funding from AstraZeneca on COVID19 vaccines. T.L.V. is an employee of AstraZeneca. S.A.M. receives honoraria from GlaxoSmithKline and AstraZeneca for work unrelated to this manuscript, institutional grants for this study from BMGF and the South African Medical Research Council and institutional grants for BMGF, GlaxoSmithKline, Pfizer, Minervax, Novavax, AstraZeneca, Providence, Greenstone, SAMRC, ImmunityBio for work unrelated to this study. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed. ### Clinical Trial NCT04444674; PACTR202006922165132 ### Funding Statement This study was funded by the Bill and Melinda Gates Foundation and the University of Oxford. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by the South African Health Products Regulatory Authority and Human Research Ethics committees of the University of Oxford, University of the Witwatersrand, University of Stellenbosch and University of Cape Town. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Data are available at [www.wits-vida.org][3]; requests for data sharing should be directed to Professor Shabir A. Madhi, email: shabir.madhi{at}wits.ac.za [1]: http://CT.gov [2]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT04444674&atom=%2Fmedrxiv%2Fearly%2F2022%2F07%2F18%2F2022.07.18.22277743.atom [3]: http://www.wits-vida.org