Avoid physical contact. Shedding occurs from feces, urine, sweat, and breathing. Proteins probably don’t last too long on surfaces. Days at most.

I’m avoiding vaccinated people until 30 days after their 2nd shot. No indoor contact. Outdoors and distanced only. No shared food, or other items.

Length of shedding is unknown. First few days are the worst. Likely they’re shedding for a week or more. Maybe longer. Possibly months but less likely. Second shot is worse.