BROADCASTS.com

The Delta variant of the coronavirus is threatening to put the world in an entirely new stage of the pandemic.\nThe variant is spreading fast, particularly in places with low vaccination rates \u2014 it is thought to be around 50 percent more transmissible than previous versions.\nWhat can be done to stop Delta, and how will the variant hamper global efforts to return to normalcy?\n\nGuest: Carl Zimmer, a science writer and author of the \u201cMatter\u201d column for The New York Times.