Many people may never be able to put the pandemic behind them. They have long Covid, a catch-all term for illness that lingers long after a Covid-19 infection. More than 200 symptoms have been reported by patients, from hair loss and incontinence to severe tremors, anxiety, extreme fatigue and heart palpitations. “Even if the pandemic virus spread were to stop today, we still have tens of millions of people suffering long Covid,” says Yale immunologist Akiko Iwasaki. “That’s a parallel pandemic that’s happening, which is getting a lot less attention than the acute and severe Covid.”