One day you're worrying about the regular old coronavirus. Then — seemingly out of the blue — there are variants. Worrisome variants! How did they come to be? And why are they likely more contagious?
Copyright 2021 NPR
One day you're worrying about the regular old coronavirus. Then — seemingly out of the blue — there are variants. Worrisome variants! How did they come to be? And why are they likely more contagious?
Copyright 2021 NPR