Long COVID Linked to Immune Inflammation (duplicated)

In a December 2025, Harvard-led study, researchers took a closer look at why some people

don’t fully recover after COVID. They followed blood samples from people months after infection,

comparing those who recovered with those who went on to develop long COVID — symptoms

like fatigue, brain fog, and exercise intolerance. What stood out wasn’t lingering virus.

Instead, the difference was the immune system. People with long COVID showed signs

of ongoing, low-grade inflammation long after the initial infection had passed — a pattern that

wasn’t seen in people who fully recovered. One of the more interesting details was timing.

People who had stronger immune activation early in infection were more likely to experience symptoms