Virus fragments could give insight into long Covid
Scientists could be a step closer to establishing what causes long Covid after finding fragments of the virus present in some people two years after infection.
It is hoped the findings could pave the way for new treatments for the condition, which is thought to affect nearly two million people in the UK.
In two related studies, researchers in California found pieces of Sars-Cov-2, or Covid antigens, lingering in the blood up to 14 months after infection and for more than two years in tissue samples.
In some of the samples, the researchers found that the virus could be active. None of the people involved in the study were still contagious.
This is the “strongest evidence to date that the Covid virus can persist long-term in some people, even if they are not immunocompromised,” said lead researcher Michael Peluso, of the University of California at San Francisco.
The team looked at blood samples of 171 people who had Covid. Not everyone had fragments of Covid in their system, and not everyone who did suffered from long Covid.
The researchers identified pieces of virus in about 10 per cent of people they examined after three to 14 months since infection.
They found it in the connective tissue where immune cells are located, suggesting that the 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.
Professor Danny Altmann, an immunologist at Imperial College London who was not involved in the study, said the research could open the door for crucial clinical trials to test treatments.
In March 2023, an estimated 1.9 million people reported that they were experiencing long Covid, representing 2.9 per cent of the population.
Based on their findings, Dr Peluso’s team is now working on several clinical trials that are testing whether monoclonal antibodies or antiviral drugs can remove the virus and improve the health of people with long Covid.
The cost to the NHS in extra GP appointments related to the condition has been estimated at up to £60m a year.