Last fall it seemed like everyone got sick—not just with COVID, but from a slew of respiratory diseases, from the mild to the severe. Researchers are trying to untangle how our immune systems have changed in the COVID era, and if we’re paying back an “immunity debt” or are victims of “immunity theft.”  Guest: Tim Requarth, contributing writer to Slate.  Host: Lizzie O’Leary If you enjoy this show, please consider signing up for Slate Plus. Slate Plus members get benefits like zero ads on any Slate podcast, bonus episodes of shows like Slow Burn and Dear Prudence—and you’ll be supporting the work we do here on What Next TBD. Sign up now at slate.com/whatnextplus to help support our work. Learn more about your ad choices. Visit megaphone.fm/adchoices