Ever since the start of the pandemic, the futures of America’s big-city downtowns have been in question. Philadelphia is just one example of a center city finding new ways to thrive.

"Long COVID has affected every part of my life," said Virginia resident Rachel Beale said at a recent Senate hearing. "I wake up every day feeling tired, nauseous and dizzy. I immediately start planning when I can lay down again." Beale is far from alone. Many of her experiences have been echoed by others dealing with long COVID. It's a constellation of debilitating symptoms that range from brain fog and intense physical fatigue to depression and anxiety. But there's new, promising research that sheds light onto some symptoms. NPR health correspondent Will Stone talks with Short Wave host Regina G. Barber about the state of long COVID research — what we know, what we don't and when we can expect treatments or even cures for it. Have more COVID questions you want us to cover? Email us at shortwave@npr.org — we'd love to hear from you.