The challenge studies they’re doing involve infecting people with measure doses of the virus. An infected person may or may not be shedding at that particular

The challenge studies they’re doing involve infecting people with measure doses of the virus. An infected person may or may not be shedding at that particular moment. Once they’ve established the MED to infect someone, they could potentially do a study with aerosols and masks, but even then, trying to simulate the right airflow and volume of viral particles is probably too difficult to be practical.