Last month, we learned about the “UK variant.” Now, more mutations from South Africa and Brazil have made headlines. How bad are they? And should you change anything you’re doing already? Dr. Vineet Menachery, a virologist at the Galveston National Laboratory who studies coronaviruses, joins to explain. Support this show and all of The Atlantic’s journalism by becoming a subscriber at theatlantic.com/supportus. Learn more about your ad choices. Visit megaphone.fm/adchoices