Long COVID Tied to Chronic Inflammation

In a December 2025, Harvard-led study, researchers analyzed blood samples from over 140 people

to understand why some develop long COVID while others recover. The main finding

was clear. Long COVID was not linked to lingering virus. Instead,

it was linked to persistent immune activation and chronic inflammation that continued for months

after the initial infection. People with long COVID showed ongoing inflammatory signaling,

signs of immune system depletion, and changes in cellular metabolism. These patterns were

not seen in people who fully recovered. Timing also mattered. Individuals with stronger inflammatory

responses early in infection were more likely to experience long-term symptoms later,