British scientists on Monday launched a trial that again deliberately exposes participants who already had COVID-19 to the coronavirus to examine immune responses and see if people become infected again.
In February, Britain became the first country in the world to give the go-ahead for the so-called ‘challenge trials’ in humans, in which volunteers are deliberately exposed to COVID-19 to promote research into the disease caused by the coronavirus. read more
The study, launched Monday, differs from the study announced in February in that it seeks to re-infect people who previously had COVID-19 in an effort to deepen their understanding of immunity, rather than infecting people for the first time.
“The information from this work will enable us to design better vaccines and treatments, and also to understand whether people are protected after having COVID, and for how long,” said Helen McShane, a vaccine specialist at the University of Oxford and principal investigator said about the study.
She added that the work will help to understand which immune responses are protected against reinfection.
Scientists have been using human challenge trials for decades to learn more about diseases such as malaria, flu, typhus and cholera, and to develop treatments and vaccines against them.
The first phase of the trial is to determine the lowest dose of coronavirus needed to be repeated in about 50% of participants, while producing little or no symptoms. A second phase, which begins in the summer, will infect different volunteers with the standard dose.
In phase one, up to 64 healthy participants, aged 18-30 years, who were infected with coronavirus at least three months ago, will be re-infected with the original strain SARS-CoV-2.
They will then be quarantined and monitored for at least 17 days, and anyone who develops symptoms will receive Regeneron monoclonal antibody treatment.
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