Scientists at the University of Oxford plan to re-infect dozens of adult volunteers with the coronavirus in the second British clinical trial to study deliberate Covid-19 infection in quarantine – this time in people who have already recovered from the virus.
Such ‘human challenge’ studies are controversial because they intentionally infect healthy people, and the UK is the only country so far to have conducted them with Covid-19, researchers said.
The new trial aims to explore the limits of human immunity and the effects of the virus on the body from the time of reinfection. A better understanding of protection against previous diseases will help accelerate new treatments and vaccines, Oxford researchers say.
The first Covid-19 challenge study, led by Imperial College London infectious disease researchers, began in March with a handful of volunteers isolated at the Royal Free Hospital in London, which is part of the state-funded National Health Service. That study received a pledge of more than $ 45 million from the UK government.
The Oxford trial is funded by the London-based Wellcome Trust, a health care charity. According to Helen McShane, an Oxford vaccineologist who leads the study, as many as 64 people aged 18 to 30 will be quarantined in staggered stages at Oxford University Hospitals at approximately 17-day intervals.