University of Oxford scientists plan to reinfect dozens of adult volunteers with the coronavirus in the second U.K. clinical trial to study deliberate Covid-19 infection in quarantine—this time among people who have already recovered from the virus.
Such “human challenge” trials are controversial because they involve intentionally infecting healthy humans, and the U.K. is the only country so far conducting them with Covid-19, researchers said.
The new trial is focused on probing the boundaries of human immunity and the effects of the virus on the body from the moment of reinfection. Better understanding of protection from previous illness will help fast-track new treatments and vaccines, Oxford researchers say.
The first Covid-19 challenge study, led by Imperial College London infectious-disease researchers, started in March with a handful of volunteers isolated inside London’s Royal Free Hospital, part of the state-funded National Health Service. That study received a pledge of more than $45 million from the U.K. government.
Oxford’s trial is funded by the London-based Wellcome Trust, a healthcare-focused charitable foundation. As many as 64 people aged 18 to 30 years will be quarantined in staggered phases inside Oxford University Hospitals at roughly 17-day intervals, starting as soon as next month, according to Helen McShane, an Oxford vaccinologist who is leading the trial.