I'm not actually in the hospitals, I work for a different company that looks at different metrics to try to reduce readmissions and raise quality of care by making sure patients comply with the orders they receive when they leave the hospital. If there were people coming in with multiple covid admissions there would be a pretty large focus on how to prevent these people from reacquiring covid. As of now I haven't seen anything. It's absolutely possible that someone could get it twice, I personally got the chicken pox twice because the first time I had a low viral load, but I think it's going to be very rare or in a case where the initial load died out before the body even had to fight it.