Scientists identify four factors that may increase risk of long Covid

Patients reported lingering symptoms such as fatigue, brain fog and shortness of breath months after their coronavirus infections cleared

(Getty Images)

There are four biological factors that may increase a person’s risk of developing long Covid, a study has suggested.

A team of researchers followed more than 200 patients for up to three months after they were diagnosed with Covid-19 and found certain factors appeared to be associated with long Covid.

It is hoped that the findings might lead to further studies into ways to prevent or treat some cases of long Covid, which sufferers say can lead to physical and neurological symptoms that linger for months after their coronavirus infections have cleared.

According to the NHS, long Covid is when symptoms of coronavirus last for weeks or months after the infection has gone. Symptoms can be either mild or severe, and range from extreme tiredness and shortness of breath and chest pain to problems with memory and concentration, insomnia, and dizziness.

The study, published in the journal Cell, suggested that one of the commonalities was a high level of coronavirus RNA in patients’ blood in the early stages of their illness, which indicates a high viral load.

Another factor is the presence of certain antibodies that are found in autoimmune diseases, which attack the body’s immune system by mistake. A third is a history of Epstein-Barr virus, which affects many people when they are young and continues to live in the body.

The last factor was type 2 diabetes, the researchers said, although the researchers said that further studies may show that diabetes is just one of a number of medical conditions that may result in long Covid.

The study’s authors cautioned that their findings were exploratory and called for more research to be conducted into the matter.

Dr Jim Heath, principal investigator of the study and president of the Institute for Systems Biology, a biomedical research non-profit based in Seattle, told the New York Times that the research “stresses the importance of doing measurements early in the disease course to figure out how to treat patients”.

“We did this analysis because we know patients will go to physicians and they’ll say that they’re tired all the time or whatever, and the physician just tells them to get more sleep,” he said, adding that this was “not very helpful”.

The study involved dozens of researchers from a number of institutions and surveyed patients who reported about 20 long Covid symptoms such as fatigue, brain fog and shortness of breath.

According to Dr Heath, 37 per cent of patients reported three or more symptoms within two or three months after becoming infected with coronavirus. Another 24 per cent had one or two symptoms, and 39 per cent had no lingering symptoms.

Of those who reported three or more symptoms, 95 per cent were found to have one or more of the four health factors when they were first diagnosed with the virus.

The study comes as new research from the Office for National Statistics suggested that the risk of developing long Covid appears to be significantly reduced after vaccination.

A study of more than 6,000 people found that those who were fully vaccinated with Pfizer or Moderna were 41 per cent less likely to report persistent symptoms 12 weeks after testing positive for Covid.

The figure dropped to 37.7 per cent for people vaccinated with AstraZeneca.