On July 8th, 2025, PNAS published a new paper titled, ‘Oxidative stress is a shared characteristic of ME/CFS and Long COVID,' which found that ‘both ME/CFS and LC donors exhibit signs of elevated oxidative stress, especially in the memory subset.'
On the 9th July, 2025, Scimex summarised the report in an article on their website, titled, “Long COVID and chronic fatigue may share features in common.”
Extracts from Scimex summary:
US scientists have looked at the characteristics of peripheral blood lymphocytes – immune cells circulating in the blood – of 27 people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), 20 with long COVID, and 25 with neither condition.
They found higher levels of oxidative stress (which damages cells) in the people with ME/CFS and long COVID than in healthy people’s cells. They also found that women with ME/CFS were less able than healthy women to clear damaging substances called reactive oxygen species from their cells.
Although this was not the case among men, those with ME/CFS had other signs of cell damage which were not seen in their healthy counterparts. The findings suggest there are similarities between ME/CFS and long COVID, the authors say.