Healthy young people recovered from Covid-19 will be re-exposed to the pandemic coronavirus to understand how the immune system reacts to a ‘new encounter’ with the pathogen. The study will start this month in the UK, with the aim of designing more effective tests, therapies and vaccines against the infection.
The trial – supported by the Wellcome Trust and coordinated by Helen McShane of the University of Oxford – will enroll up to 64 volunteers between the ages of 18 and 30, who will spend 17 days in a hospital-based quarantine unit and undergo numerous tests, including lung tests. The deliberate reinfection will take place in a “safe and controlled environment,” the BBC reports online, “under strict medical supervision.”
Participants will be exposed to the original Sars-CoV-2 strain, the Wuhan coronavirus. The first phase of the study aims to establish what is the lowest ‘dose’ of virus that can infect volunteers, starting to replicate in the target organism, but giving rise to an asymptomatic or paucisymptomatic infection. This viral dose will then be used to infect participants in a second step of the research, which is expected to begin in the summer. Volunteers who develop symptoms will receive antibody treatment and will only be discharged when they are no longer able to transmit the coronavirus.
The so-called “challenge studies tell us things that other studies cannot tell us – explains McShane – because, unlike natural infections”, those induced in this kind of trial are “strictly controlled. When we reinfect these volunteers we will know exactly how their immune system is. reacted to the first infection, when the second occurs and how much viruses they came in contact with. In addition to improving our understanding of the disease, this type of research can help us design tests that can accurately predict whether people are protected. ” .
According to Lawrence Young of Warwick University, these studies “will significantly improve our understanding of the dynamics of viral infection and the immune response, as well as provide valuable information to help us develop new vaccines and antiviral therapies.”