Long Covid is a condition that has been continuously misunderstood for four years. Sufferers experience symptoms such as fatigue, feeling short of breath, loss of smell and muscle aches, according to the NHS. 1.9 million people in the UK are reported to have it.
Until now, scientists didn’t know for sure what caused the debilitating condition, with the most recent research pointing to overactive immune cells releasing high levels of inflammatory substances that can injure organs and tissues.
However, this week, scientists have revealed that they may now have found the cause of long Covid in a pioneering pair of studies which could pave the way for treating the condition.
What is the cause of long Covid?
In two separate but related studies, researchers in California reported finding pieces of Covid antigens in the blood up to 14 months after infection and for more than two years in tissue samples.
In some of these samples, the virus was still found to be active and lead researcher Michael Peluso said that these findings present the “strongest evidence to date” that Covid can persist long-term in some people, even if they’re not immunocompromised.
The researcher added that this could be a driver of some types of long Covid or other dramatic impacts that people have experienced post-Covid, like heart attacks.
In their review of 171 blood samples of people that had been infected with Covid, researchers found that not everyone who was previously infected had fragments of Covid in their system and even those that did, didn’t always develop long Covid.
In fact, the team identified pieces of the virus in about 10% of the people that they examined, after 3-14 months since infection. It was found in connective tissue where immune cells are located, suggesting that the viral fragments could be causing the immune system to attack.
Among those who were hospitalised with Covid, the likelihood of detecting virus antigens was about twice as high as it was for those who were not. It was also higher for those who reported being sicker, but were not hospitalised, the scientists found.
Professor Lawrence Young, of Warwick University, said: “Learning more about the drivers of long Covid is providing insights that will improve our ability to diagnose this condition and provide opportunities for therapeutic intervention.”
This research, which was presented at the Conference on Retroviruses and Opportunistic Infections earlier this month, could revolutionise treatment for long Covid.