Again if they were sick enough to donate plasma if they have a cough they can test positive months later. South Korea had this same thing. They could not culture the virus it was dead but the symptoms had returned. Symptoms are due to your immune system. No offense if they had a lab confirmed cultures etc case of reinfection much less two it would have made news every where around the world. Below is a link from South Korea. The antibodies most often associated have a half life of six weeks. Every single country on the planet has reported the same thing. This would literally be the first respiratory virus we have no immunity after recovery too.

https://www.google.com/amp/s/mobile..../idUSKBN22J0HR