Initially, trial subjects will be quarantined and compensated for an expected period of two to 2½ weeks, the group of researchers said. Scientists plan to expose the volunteers initially with the smallest dose possible until they find a level that reliably causes infection. The virus will be injected as droplets through the nose.

That first phase of the study doesn’t involve a vaccine, scientists said. After the researchers better understand infection levels and participant responses, they will integrate vaccines to measure their effectiveness when volunteers encounter the virus…

During the challenge trials, treatments, which will initially include the antiviral drug remdesivir, will be at the ready and administered most likely before the volunteers even show symptoms, in an effort to limit the risk of severe disease, Dr. Chris Chiu, the study’s lead researcher from Imperial College, said in a media briefing Tuesday.