Major trial launches for oxford COVID-19 vaccine

NCT ID NCT04400838

First seen Jun 26, 2026 · Last updated Jun 26, 2026

Summary

This large study tested the Oxford-AstraZeneca COVID-19 vaccine (ChAdOx1 nCoV-19) in over 10,000 healthy UK adults aged 18 and older. The goal was to see if the vaccine safely prevents symptomatic COVID-19. Participants received either the vaccine or a control shot, and researchers tracked cases and side effects.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance
ChAdOx1 nCoV-19 (Oxford-AstraZeneca COVID-19 vaccine)
What this could lead to
If successful, this vaccine could help protect people from COVID-19, reducing illness and spread of the virus.
What could go wrong
This is an early combined phase 2/3 trial, so results may not confirm long-term protection or safety for all populations. Side effects like fever or fatigue are possible.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • CCVTM, University of Oxford, Churchill Hospital

    Oxford, OX3 7LE, United Kingdom

  • Castle Hill Hospital

    Cottingham, Hull, HU16 5JQ, United Kingdom

  • Glasgow University and NHS Greater Glasgow & Clyde, New Lister Building, Glasgow Royal Infirmary & Queen Elizabeth University Hospital

    Glasgow, G31 2ER, United Kingdom

  • Guy's and St Thomas' NHS Foundation Trust, Department of Infection, St Thomas Hospital

    London, SE1 7EH, United Kingdom

  • Imperial College Healthcare NHS Trust

    London, W12 0HS, United Kingdom

  • John Radcliffe Hospital

    Oxford, OX3 9DU, United Kingdom

  • Liverpool School of Tropical Medicine (LSTM), Accelerator Research Clinic. Clinical Sciences Accelerator

    Liverpool, L7 8XZ, United Kingdom

  • London North West University Healthcare Trust (LNWUH), Northwick Park Hospital

    London, HA1 3UJ, United Kingdom

  • NHS Lothian, Western General Hospital

    Edinburgh, EH4 2XU, United Kingdom

  • NIHR Cambridge Clinical Research Facility

    Cambridge, CB2 0QQ, United Kingdom

  • North Bristol NHS Trust

    Bristol, United Kingdom

  • Public Health Wales

    Newport, NP18 3XQ, United Kingdom

  • Sheffield Teaching Hospitals, Royal Hallamshire Hospital

    Sheffield, S10 2RX, United Kingdom

  • St Georges University Hospital NHS Foundation Trust

    London, Tooting, SW17 0QT, United Kingdom

  • The Newcastle upon Tyne Hospitals NHS Foundation Trust, Royal Victoria Infirmary

    Newcastle upon Tyne, NE1 4LP, United Kingdom

  • University College London Hospitals NHS Foundation Trust

    London, NW1 2PG, United Kingdom

  • University Hospital Southampton NHS Foundation Trust

    Southampton, Hampshire, SO16 6YD, United Kingdom

  • University Hospitals Birmingham NHS Foundation Trust

    Birmingham, United Kingdom

  • University Hospitals Bristol and Weston NHS Foundation Trust

    Bristol, BS1 3NU, United Kingdom

  • University of Nottingham Health Service, Cripps Health Centre, University Park

    Nottingham, NG7 2QW, United Kingdom

More trials for these conditions

Other studies related to the condition(s) this trial covers.