UK human ‘challenge trial’ launched
Tuesday, April 20th, 2021
A year-long trial was launched Monday to study how the immune system reacts in people contracting coronavirus for the second time.
Volunteers in the UK who’ve previously had Covid-19 will be deliberately infected with the virus to discover what it may mean for developing immunity.
The so-called “challenge trial” will happen under carefully controlled conditions, with treatments on hand in case volunteers becomes ill, the team at the University of Oxford said.
“Challenge studies tell us things that other studies cannot because, unlike natural infection, they are tightly controlled. When we re-infect 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,” Dr. Helen McShane, a vaccine specialist at the University of Oxford, said in a statement.
The first phase of the study, starting this month, will find the lowest dose of virus that can infect half of coronavirus survivors without causing symptoms.
Then all 64 volunteers will be infected with that dose. Their immune responses will be studied.
Participants will initially be monitored 24/7 for two weeks while they quarantine in a specially designed hospital suite where they will undergo medical tests, including CT scans of the lungs and MRI scans of the heart.
Any volunteers who develop symptoms will be treated with Regeneron’s monoclonal antibody treatment and discharged from quarantine only when they are at no risk of infecting others.
Speaking on Radio 4’s Today program on Monday, McShane said: “One of the things we can determine with this study is how long that protection lasts.
Once we understand exactly the immune response that protects against second infection, we can then use that information to develop vaccines more quickly, test vaccines more quickly, and understand who is protected and who isn’t from this virus.”
McShane said they’ll be recruiting people who are young and healthy – ages 18 to 30 -- with the “lowest possible risk of serious consequences from this infection.”
Delhi, India’s capital, will be under lockdown for one week until next Monday, April 26, the chief minister announced on Monday.
“If we don’t put a lockdown now we may end up in a tragedy,” Arvind Kejriwal, the chief minister of Delhi said.
As part of the lockdown, there will be a curfew on movement, starting 10 p.m. local time this Monday until 5 a.m. on April 26. However, essential products and service providers will be exempt from this rule.
All private offices and establishments, such as shops, malls, gyms, cinema halls and swimming pools, will remain closed, Delhi’s Disaster Management Authority said on Monday. - Agencies