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.
