Caroline Nicolls receives an injection of the Moderna Covid-19 vaccine administered by nurse Amy Nash at Madejski Stadium in Reading, west London, on April 13, 2021.
STEVE PARSONS | AFP | Getty Images
LONDON – Researchers at the University of Oxford announced on Monday the launch of a human challenge process to better understand what happens when people who have already contracted coronavirus become infected for the second time.
The researchers will examine what kind of immune response might prevent people from reinfecting themselves with Covid-19 and investigate how the immune system reacts to the virus a second time.
Currently, little is known about what happens to people who have already had the virus when they are infected a second time.
The process will take place in two stages, with different participants in each phase. The first phase is scheduled to begin this month, and the second phase will begin in the summer.
In medical research, human challenge studies are controlled studies that involve the deliberate exposure of participants to a pathogen or error to study the effects.
“Challenging studies tell us things that other studies can’t do because, unlike natural infection, they are strictly controlled,” said Helen McShane, chief investigator of the study and professor of vaccinology at the Department of Pediatrics, Oxford University .
“When we re-infect these participants, we will know exactly how their immune system reacted to the first COVID infection, exactly when the second infection occurs, and exactly how much they received the virus,” McShane said.
It is hoped that the study will help improve scientists’ basic understanding of the virus and help design tests that can reliably predict whether humans are protected.
What happens in each phase?
For the first phase, up to 64 volunteers between the ages of 18 and 30 who were previously naturally infected will be re-exposed to the virus under controlled conditions.
Researchers will monitor participants’ care while they are subjected to CT scans of the lungs and MRI scans of the heart, while isolating themselves in a specially designed suite for at least 17 days.
All participants must be fit and well and must have fully recovered from their first Covid infection to minimize the risk.
Participants in the trial will be released from the quarantine unit only when they are no longer infected and risk spreading the disease.
A view of London on a clear day.
Vuk Valcic | Images SOUP | LightRocket via Getty Images
The second phase of the process will explore two different areas.
“First of all, we will carefully define the basic immune response in volunteers before infecting them. We will then infect them with the dose of virus chosen from the first study and measure how much virus we can detect after infection. to be able to understand what kind of immune responses protect against reinfection, “McShane said.
Second, we will measure the immune response at various points in time after infection so that we can understand what immune response is generated by the virus, she added.
The full duration of the study will be 12 months, including at least eight subsequent meetings after discharge.
“This study has the potential to transform our understanding by providing high-quality data on how our immune system responds to a second infection with this virus,” said Shobana Balasingam, senior advisor in vaccine research at Wellcome, a foundation charity that funds the study.
The findings could have important implications for how we deal with COVID-19 in the future, and inform not only the development of the vaccine, but also research into the range of effective treatments that are also urgently needed. said Balasingam.