You’ve heard of long Covid, a condition in which the acute infection subsides but troubling symptoms persist. Less well known is chronic Covid: The virus just doesn’t leave, sometimes staying in patients’ bodies long enough to mutate into new variants. This happens to people whose immune systems are compromised, whether through disease or treatment, leaving them vulnerable to infections that last weeks, months, or, in one known case, a year.
New research published Wednesday in Science Translational Medicine analyzed how long it took for people with different levels of immune compromise to clear the virus, and how that virus evolved along the way. The work highlights the spectrum of risk for Covid becoming chronic — from high levels for people with blood cancers requiring bone marrow transplants, lower risk for people taking immune-suppressing drugs for autoimmune illness, and little risk for those with intact immunity. The 56 immunocompromised people in the study had a variety of conditions, but they all fall into a category of people overlooked as many in the world have moved on from the pandemic in its fifth year.