A U.K. study is offering young, healthy people who have recovered from COVID-19 the opportunity to relive the experience — all in the name of science.
The University of Oxford study, known as a “human challenge,” hopes to uncover how much of the virus is required for reinfection, how the immune system responds and how long protective immunity lasts. The one-year study, which will pay participants aged 18 to 30 around $8,700 for their time, is set to begin this month after receiving ethics approval, according to Yahoo! News.
“Challenge studies tell us things that other studies cannot because, unlike natural infection, they are tightly controlled,” said Helen McShane, chief investigator of the study and a professor of vaccinology at the department of paediatrics at the University of Oxford. “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 much virus they got.
“As well as enhancing our basic understanding, this may help us to design tests that can accurately predict whether people are protected.”
Although natural reinfection from COVID-19 is rare, a Lancet study involving members of the U.S. Marine Corps found around 10 per cent of participants experienced a second natural infection after recovering from their first encounter with the virus. Similar challenges have been employed to advance knowledge and treatment of TB, typhoid, malaria, cholera and the flu.
The first stage of the study involves splitting 24 participants — all of whom were infected at least three months before the start of the trial — into three groups of eight and subjecting them to increasing quantities of the virus. “Our target is to have 50 per cent of our subjects infected but with no, or only very mild, disease,” McShane said.
This information will be used to infect and study a separate group of patients in the second stage of the study, expected to commence in the summer.
“We will measure the immune response at several time points after infection so we can understand what immune response is generated by the virus,” she said. “A challenge study allows us to make these measurements very precisely because we know exactly when someone is infected.”
Researchers intend to use the original strain of COVID-19 from Wuhan, China because it is the version for which most clinical, immunological and virological data exists but preliminary discussions are underway to incorporate at least one of the variants of the virus into the study. After infection, participants will be quarantined for 17 days under the watchful eyes of a research team armed with a monoclonal antibody treatment that has demonstrated the ability to minimize the more serious symptoms of the virus.
The 12-month study includes eight follow-up appointments with researchers once participants have recovered from their second encounter with COVID-19.
“The information from this work will allow us to design better vaccines and treatments, and also to understand if people are protected after having COVID, and for how long,” McShane said.
The information this study yields could prove invaluable, said Danny Altmann, a professor at Imperial College London. “Human challenge studies can be done safely and ethically to fast-track discoveries in infectious disease and vaccine research,” he said. “Some of the key points that can’t easily come out of other, less controlled studies are the earliest immune correlates of the response to infection.”
Dave Yasvinski is a writer with Healthing.ca
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