UK human 'challenge trial' launched to study COVID-19 reinfection

The first phase of the study, starting this month, will find the lowest dose of virus that can infect half of the coronavirus survivors without causing symptoms. 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.

London: A year-long trial was launched on Monday to study how the immune system reacts in people contracting COVID for the second time. The media reported that 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 "challenge trial" will happen under carefully controlled conditions, with treatments on hand in case volunteers become 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 media also reported that the first phase of the study, starting this month, will find the lowest dose of virus that can infect half of the COVID-19 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 are in 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.

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.

"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 the 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 in an interview.

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."

(ANI)