Long Covid may be result of body trying to fight off other viruses

LONG COVID symptoms may be driven by the reactivation of dormant viruses such as herpes, scientists have suggested, after finding evidence of inflammation in the blood of sufferers.

At the last count by the Office for National Statistics last year, some 1.9 million people reported symptoms of long Covid, which can include fatigue, brain fog and muscle aches.

Now Imperial College and the University of Leicester, have found in long Covid sufferers, the immune system is still active long after a Covid infection has cleared up, with tell-tale signs of inflammatory proteins detectable in the blood. Experts said this inflammation may be caused by trace amounts of Covid-19 lingering in the body; autoimmunity, when the immune system attacks the body’s own tissues; or even the reactivation of other viruses.

Imperial’s Dr Felicity Liew said: “Even though the acute phase of illness resolves, there may be virus persisting in the body that could continually trigger the immune system and cause the ongoing inflammation that we found.

“It can also cause reactivation of herpes viruses or people that previously had glandular fever caused by Epsteinbarr virus, and it can cause that to reactivate and cause ongoing symptoms.

“Or it can result in auto-immunity, and all of those scenarios result in the types of inflammation that we see, and could result in chronic and ongoing abnormal inflammation represented by these proteins highlighted here.”

The analysis looked at blood plasma from 426 people treated in hospital with Covid who had experienced long-term symptoms and compared them with blood from people with no ongoing problems. The study is published in the journal Nature Immunology.