Scientists deliberately infected people with coronavirus. Here’s what happened | Science | AAAS

"Researchers in the United Kingdom yesterday posted the results of a first-of-its-kind study in which healthy young volunteers were purposely infected with an early strain of the pandemic coronavirus. As hoped, none of the participants got seriously ill, and scientists were able to closely track their symptoms and gain unique insight into how both SARS-CoV-2 levels and symptoms vary from start to finish during an infection...."