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BSI response to published interim phase 3 trial results for University of Oxford COVID-19 vaccine

8 December 2020

Today, the University of Oxford, in collaboration with AstraZeneca plc, have published the pooled analylsis of the interim phase 3 trial results of the ChAdOx1 nCoV-19 vaccine against COVID-19 in The Lancet. In response, the British Society for Immunology has released the following statement:


Professor Deborah Dunn-Walters, Chair of the British Society for Immunology COVID-19 and Immunology Taskforce and Professor of Immunology at the University of Surrey said:

“Today’s publication in The Lancet of the pooled analysis of the interim phase 3 trial results of the University of Oxford/AstraZeneca COVID-19 candidate vaccine, ChAdOx1 nCoV-2019, is good news. The research team should be commended for publishing the interim results of this trial in a peer review journal so quickly to allow scrutiny from the scientific community.

“Phase 3 trials are designed to assess both the safety and effectiveness of vaccines in a large group of people who volunteer to take part. The finding that no individual who received the COVID-19 vaccine subsequently suffered from severe COVID-19 disease is particularly reassuring. Intriguingly, the team report a higher efficacy of up to 90% when using a halved first dose and standard second dose compared with giving two standard doses.  This finding warrants further investigation, particularly as there were differences in participants’ age profile between these parts of the trial - we know that for many other vaccines, age is often linked to effectiveness. The paper reports reassuring findings on the safety front with a good safety profile across the arms of the trial reported.

“While the findings reported today are positive, there are still more stages to go through before this vaccine can be approved for use.  In particular, we are reliant on the expert independent assessment by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA).

“The researchers working on this vaccine, both in the UK and globally, should be applauded for their monumental efforts in developing this vaccine so quickly. The UK leads the world for the quality of our immunology research and this is another great example of how the community has come together to drive forward scientific discovery into this pandemic. Equally, we all owe a huge debt of gratitude to the many thousands of people who have volunteered to take part in these trials – they have played a critical part in the development of this vaccine.”


Read the full paper that this statement is in response to:

Voysey et al. 2020 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. The Lancet doi: 10.1016/S0140-6736(20)32661-1