https://www.npr.org/sections/goatsandsoda/2021/02/02/961668700/whats-going-on-with-all-these-coronavirus-variants-an-illustrated-guide?t=1612534786998
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?