May 27, 2021

expert comments in response to comments made by Dominic Cummings yesterday about human challenge trials and vaccine development

Whilst giving evidence to a joint session of the Commons Heath, and Science and Technology committees on Wednesday, Dominic Cummings made comments about challenge trials and whether, if they had been carried out earlier, they could have sped up vaccine development.

Prof Helen McShane, Professor of Vaccinology at the Department of Paediatrics, University of Oxford, said:

“With hindsight, if we had started the GMP manufacture of a viral strain in March, we would have been able to start the challenge studies in the autumn, as by then it was clear that there was a very low risk population one could ethically enrol.  The decision in March would have had to have been taken at financial risk as it was not clear at that point whether or not it would ever be possible to do such trials.

“If we’d done this, we might have known the vaccines were effective a few weeks earlier than we did.

“More importantly, if we’d done this, we would now have an established model with which to test anti-virals and monoclonals, and new variant vaccines.  We would also have been able to define protective immunity and correlates of protection sooner, thus expediting next generation vaccine development.”

Prof Eleanor Riley, Professor of Immunology and Infectious Disease, University of Edinburgh, said:

“The exact timing of when Dominic Cummings thinks we might have done a challenge trial is crucial.

“Firstly, we have been learning more and more about the risk factors for severe COVID-19 all through the pandemic.  There are risk factors that we know about now that we didn’t know about  a year ago or even six months ago.  And we still don’t have a very good idea at all about the risks factors for developing long-Covid.  Without a very clear understanding of the risks – of severe acute COVID-19 and long-Covid – we are putting volunteers at an unquantifiable risk.  And we still don’t have any effective anti-viral drugs to short-cut an infection if we see something going wrong.  All of these issues raise significant ethical concerns.

“Secondly, at the time that the phase three clinical trials were taking place (i.e. the efficacy trials that might have been pre-empted by a challenge trial) the companies were setting up their manufacturing capability and starting to stockpile vaccine.  So it is debatable whether the vaccine roll out could have been accelerated very much even if we had got a positive signal earlier.”

https://parliamentlive.tv/event/index/d919fbc9-72ca-42de-9b44-c0bf53a7360b

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

Declared interests

Prof Helen McShane: “I have grant funding from the Wellcome Trust to do a challenge study which is now underway.  I have no personal financial interest.”

Prof Eleanor Riley: “No COIs.”