"5 years later, long Covid is still a medical mystery: What scientists have learned"
"The U.S. may be coming through the first post-pandemic winter without a major surge in cases, but each infection carries a risk of developing long Covid."
Another quote:
It’s unclear whether one or a combination of these factors causes long Covid, experts say. But evidence suggests that they’re all associated with increased inflammation in the body, Koralnik said, which is why your risk of long Covid increases with each Covid infection.
“It’s like a river going over a dam …The more episodes of Covid, the more the river level goes up to the point it overflows and there’s a flooding of long Covid symptoms.”