Throughout the pandemic, long Covid — symptoms that occur after the initial coronavirus infection — has remained something of a medical mystery.Now, amid the latest surge of infections, a series of major studies are shedding light on the condition.Guest: Pam Belluck, a health and science reporter for The New York Times.Want more from The Daily? For one big idea on the news each week from our team, subscribe to our newsletter. Background reading: Long Covid has become one of the most daunting legacies of the pandemic.Some research has shown that lingering symptoms are more prevalent in people in their 30s and 40s — when workers are often in the prime of their careers.For more information on today’s episode, visit nytimes.com/thedaily. Transcripts of each episode will be made available by the next workday.