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BSI response to pause in Oxford University coronavirus vaccine trial

9 September 2020

Today, AstraZeneca and Oxford University announced that they have paused their trial of their coronavirus vaccine candidate (ChAdOx1 nCoV-19) while they investigate an unexplained illness in one of the participants in the phase 2/3 trials currently being conducted.  In response, the British Society for Immunology has put out the following statement:


Dr Doug Brown, Chief Executive of the British Society for Immunology, said:

"Vaccines can prevent illness and save lives but it is also vital that they are thoroughly tested before being rolled out on a wide scale to ensure they are safe to use.  Because safety is so critical, vaccine trials are incredibly complex and each vaccine goes through many stages of testing both in the lab and in clinical trials.  All vaccine clinical trials have numerous strict safety procedures in place to monitor the health of participants. What we are seeing with the news that the AstraZeneca–Oxford University coronavirus vaccine trial has been paused due to ill health in one participant is one of these safety procedures kicking in.  As we all know, people fall ill for a multitude of reasons and the project team will now be reviewing in depth what is the cause of this person's illness and whether it is linked to having been given the vaccine or not.  To be ultra cautious, the trial is paused while this process is carried out – this is another of the safety procedures in built to all vaccine trials.   We will have to await the findings of this review to find out more, but it's worth highlighting that this type of pause to a vaccine trial to investigate an unexplained illness is not an uncommon event and in fact it's exactly what we should all want to see the vaccine researchers doing to ensure the safety of any potential vaccine above everything else.

“However, this news does provide a good illustration of why conducting thorough and robust vaccine trials is so critical and is just one more reason why we must not put pressure on researchers to rush through a vaccine for widespread use before these large and complex trials have been carried out.”