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The University of Oxford, in collaboration with AstraZeneca plc, today announces interim trial data from its Phase III trials that show its candidate vaccine, ChAdOx1 nCoV-2019, is effective at preventing COVID-19 (SARS-CoV-2) and offers a high level of protection.

Vial of the ChadOx (ChAdOx1 nCoV-2019) vaccine. Photo credit: John Cairns © John Cairns
  • Phase 3 interim analysis including 131 Covid-19 cases indicates that the vaccine is 70.4% effective when combining data from two dosing regimens
  • In the two different dose regimens vaccine efficacy was 90% in one and 62% in the other
  • Higher efficacy regimen used a halved first dose and standard second dose
  • Early indication that vaccine could reduce virus transmission from an observed reduction in asymptomatic infections
  • There were no hospitalised or severe cases in anyone who received the vaccine
  • Large safety database from over 24,000 volunteers from clinical trials in the UK, Brazil and South Africa, with follow up since April
  • Crucially, vaccine can be easily administered in existing healthcare systems, stored at ‘fridge temperature’ (2-8 °C) and distributed using existing logistics
  • Large scale manufacturing ongoing in over 10 countries to support equitable global access

Professor Andrew Pollard, Director of the Oxford Vaccine Group and Chief Investigator of the Oxford Vaccine Trial, said:

‘These findings show that we have an effective vaccine that will save many lives. Excitingly, we’ve found that one of our dosing regimens may be around 90% effective and if this dosing regimen is used, more people could be vaccinated with planned vaccine supply. Today’s announcement is only possible thanks to the many volunteers in our trial, and the hard working and talented team of researchers based around the world.’

Professor Sarah Gilbert, Professor of Vaccinology at the University of Oxford, said:

‘The announcement today takes us another step closer to the time when we can use vaccines to bring an end to the devastation caused by SARS-CoV-2. We will continue to work to provide the detailed information to regulators. It has been a privilege to be part of this multi-national effort which will reap benefits for the whole world.’ 

Further information is available on the University of Oxford website

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