Young people who have previously had COVID-19 will be deliberately exposed to the virus for the second time, in a new study that aims to see how their immune systems react.
Oxford University’s “human challenge” trial also hopes to find out what dose of coronavirus is needed to cause reinfection and what it can mean to develop a protective immunity against the disease.
People aged 18 to 30 who have previously become naturally infected with COVID will be recruited and re-exposed to the virus in a safe and controlled environment.
Participants will be quarantined for 17 days and will be cared for by researchers at a hospital until they stop being at risk of infecting others and will receive just under £ 5,000 as payment.
Recent research has suggested that previous infection may not fully protect young people in the future, with an observational study conducted in the U.S. indicating that 10% of participants ended up being re-infected.
Studies on human challenge have played a key role in the development of treatments for diseases such as malaria, tuberculosis, typhus, cholera and influenza.
Professor Helen McShane, chief researcher, said: “Challenge studies tell us things that other studies cannot do because, unlike natural infection, they are tightly controlled.
“When we reinfect these participants, we will know exactly how their immune system has reacted to the first COVID infection, exactly when the second infection occurs, and exactly how many viruses they have.
“In addition to improving our basic understanding, this can help us design tests that can accurately predict whether people are protected.”
Regular reviews the year after reinfection will help establish the immune response generated by the virus, which could contribute to the creation of better vaccines and a better understanding of the duration of immunity.
The original Wuhan COVID-19 strain will be used because it is the one that has the most information about scientists, but another variant could also be included.
The study will be developed in two phases.
The first phase, with 64 healthy volunteers, will aim to establish the lowest dose of virus you can catch and begin to replicate.
Once the dosage amount is established, it will be used to infect participants in the second phase of the study, which is expected to begin in the summer.