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- Primary analysis, part of pre-specified trial protocol, follows interim analysis on Monday 22 March - Data are consistent with interim analysis, and will form submission by AstraZeneca to US FDA - Vaccine 76% effective against symptomatic COVID-19, and 100% effective against severe or critical disease and hospitalisation

Our vaccine work is progressing quickly. To ensure you have the latest information or to find out more about the trial, please visit the Oxford COVID-19 vaccine web hub or visit the COVID-19 trial website.

Our partners AstraZeneca have today announced the high-level results from the primary analysis of their Phase III trial of the ChAdOx1 nCoV-19 coronavirus vaccine in the US. They confirm that the vaccine efficacy is consistent with the interim analysis results announced on Monday 22 March 2021.

This primary efficacy analysis included the accrual of 190 symptomatic cases of COVID-19 from the 32,449 trial participants, an additional 49 cases to the previously announced interim analysis.

In addition, results were comparable across age groups, with vaccine efficacy of 85% in adults 65 years and older. A key secondary endpoint, preventing severe or critical disease and hospitalisation, demonstrated 100% efficacy.

AstraZeneca have presented these results to the independent Data Safety Monitoring Board, and this primary analysis, which was pre-specified in their trial protocol, will be the basis for their regulatory submission for Emergency Use Authorization to the US Food and Drug Administration in the coming weeks.

AstraZeneca also plan to submit these data for peer-review in scientific literature in the coming weeks.