Young people to take part in new virus double-infection experiment

Healthy, young volunteers who have previously had Covid-19 will be deliberately exposed to the virus for a second time to see how the immune system reacts as part of a new UK study.

Researchers at Oxford University have launched what is known as a “human challenge” trial to look at what happens when someone who has recovered from Covid-19 infection is then re-exposed to the virus.

They will aim to determine what dose of virus is needed to re-infect after natural infection, how the immune system responds, and what this may mean for developing protective immunity against the disease.

The study, which is funded by the Wellcome Trust and is expected to start this month, will recruit people aged 18-30 who have previously been infected with Covid-19.

They will be re-exposed to the virus in a safe and controlled environment while a team of researchers monitor their health.

Helen Mcshane, professor of vaccinology at the department of paediatrics, Oxford University and chief investigator on the study, said: “Challenge studies tell us things that other studies cannot because, unlike natural infection, they are tightly controlled.

“As well as enhancing our basic understanding, this may help us to design tests that can accurately predict whether people are protected.”

While Covid-19 infections have been rare, recent research suggests prior infection may not fully protect young people against reinfection.

It is hoped the study will help scientists to greater understand immunity to the virus after infection.