The virus had not cleared in those cases or they caught something else. Covid leaves some with lingering pulmonary damage that may take weeks or months to improve. Some appear to have ongoing lingering fatigue and cardiac changes. No documented cases yet of “catching it again” but whether one may catch a differing strain or not is an issue that they are still working on.
https://www.nytimes.com/2020/08/24/health/coronavirus-reinfection.html
Guy in Reno was first documented American:
https://nypost.com/2020/08/28/nevada-man-becomes-first-in-the-us-to-catch-covid-19-twice/
The bad news about the Nevada case is he was more sick the second time.
I had just had the virus. Even though I’m negative now, the symptoms just lingers on. It’s the COVID brain they call it. I it’s a vibration of the brain. It’s hard to describe.