That should have been a known. Every time there is a wisp of air, the virus will be lifted up and floated on down the hall. Every time a nurse attends a patient, it will waft up onto the clothing and catch a free ride.
My son says that the on the covid floor at the hospital he works with, the nurses stations are surrounded by the patient rooms which are all set up as isolation rooms. However, the nurses at the stations in the middle don’t even wear masks.
He says everyone on that floor should be in tyvek suits, etc.