Corbin Burnes did test positive for COVID-19, the reason he landed on the illjured list. He stayed asymptomatic the entire time:

“I had some weights at the apartment, so I was able to do some workouts on the floor of the apartment,” Burnes said. “And I had my wife’s Peloton here, so I was able to do some big conditioning workouts and keep the cardio in shape.

“There’s a little grass field right outside our apartment complex and I had a net. I was fortunate to have some balls and stuff with me from the offseason, so I was able to throw into a net every day and do everything in my power to keep the arm, to keep the body ready.”

ESPN.com

Burnes opted out of the vaccine, and wound with the natural form of gaining immunity. It just cost him ten days of the season.