In casual discussion of the virus, the term "Long Haulers" is, generally, used to describe people for whom symptoms of Covid-19 can linger for weeks and months, long after the worst seems to be over. And that can be debilitating.
But that’s not the only kind of ‘long-hauler’. There are also people, we’re learning, who recover, but continue to test positive weeks later. Even without any symptoms. How long can this virus linger inside people? What can other diseases that stay with people for years and even lifetimes tell us about what we’re seeing in these cases with Covid? What do we still not know about how all this works?
GUEST: Roxanne Khamsi, science writer