The first ever “human challenge” trial for COVID-19 has been determined to be safe by authorities in the United Kingdom, paving the way for future research.
The trial, which began in February 2021 and was run by Open Orphan, Imperial College of London, Britain’s Vaccine Taskforce and hVIVO, exposed 36 healthy young adults to the original strain of COVID-19 and then observed them in quarantine. They will be followed up with for 12 months post-discharge, according to Reuters.
Scientists behind a British trial that deliberately infected young adults with #COVID19 say their study was safe for healthy young adults–and, as hoped, yielded valuable insights about the virus, @Reuters reports. https://t.co/ubHp5ZROCg
— Global Health NOW (@ghn_news) February 2, 2022
The data from this trial, which found no serious adverse effects in the participants, will allow for more human challenge trials to begin by the end of this year to test new vaccines and drugs against the virus, the researchers said.
The researchers from Imperial College London said they will soon begin a similar trial studying the Delta variant, which ravaged much of the world last year. In April, a human challenge trial to study natural immunity was launched at Oxford University by re-infecting people who had already recovered from COVID-19, according to Reuters.
Results of the Imperial study offer some new insights into the virus. Symptoms began developing after an average of about two days in the participants, faster than the generally-believed consensus that the virus has an incubation period of about five days. The subjects had virus in their nose for an average of about six and a half days, Reuters reported.
Eighteen of the volunteers were ultimately infected, 16 of whom had mild symptoms. None developed serious symptoms, but 13 did lose their sense of smell for some time. Ten of them regained their smell within 90 days, and the other three showed improvement after that period. (RELATED: Justin Trudeau Tests Positive For COVID-19 As Anti-Mandate Protesters Flood Ottawa)
Scientists are now studying why the remaining 16 participants were not infected with the virus. Some were detected with a level of virus in their nose, but did not have enough to meet the threshold of a positive PCR test.