The idea that Covid-19 emerged from a Chinese lab once sounded too fringe to take seriously. That’s starting to change. Transcript at vox.com/todayexplained. Support Today, Explained by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit megaphone.fm/adchoices Learn more about your ad choices. Visit podcastchoices.com/adchoices