Scientists Investigate Mystery of Long Covid

 “As vaccines blunt the threat of severe illness and death from Covid-19, millions of people remain at risk of developing an array of less serious but potentially debilitating long-term symptoms of the disease that scientists call long Covid.
Many of the most vulnerable are among younger unvaccinated people who are unprotected against the rapidly spreading Delta variant of the coronavirus, nowresponsible for more than 80% of America's growing caseload.
Long Covid -- a term referring to symptoms that linger for weeks or months beyond infection -- affectsbetween 10% and 30% of people who catch the virus, including those with mild or asymptomatic infections, according to experts. In some cases, symptoms persist for more than a year.
"Even if it's not as striking as people dying, you ignore it at your peril," said Danny Altmann, professor of immunology at Imperial College London. "In terms of healthcare burden or healthcare cost, we're on track for this being as big a problem to us as rheumatoid arthritis, the biggest autoimmune disease in the world."
Many Americans remain unvaccinated or only partially vaccinated. Cases arerising as states relax restrictions and the highly transmissible Delta variant spreads. That increase won't cause as much serious illness or death as in previous waves, thanks to high vaccination uptake among the oldest and most vulnerable. But it could lead to tens of thousands of new cases of long Covid.
"Long Covid is real," said Priya Duggal, professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health. "Now we have a whole group of individuals who have survived Covid who are going on into a chronic [long-term] state that will likely be with us for a really long time."
The scale of the issue has spurred governments to pour large sums into researching long Covid. The National Institutes of Health has committed $1.15 billion over four years for investigating the condition, while its U.K. counterpart has so far provided nearly $54 million to fund research investigating causes, diagnostic methods and possible treatments.
Long Covid is associated with a bewildering array of possible symptoms; a recentsurvey of people with confirmed or suspected long Covid by researchers at University College London identified more than 200, spanning visual hallucinations, heart palpitations and memory loss.
Still, certain symptoms crop up repeatedly. The majority of people with long Covid report fatigueas the dominant symptomalongside muscle aches, difficulty sleeping and shortness of breath, according to alarge studyby researchers at Imperial College London. Another, smaller, cluster of patients reportedpredominantlyrespiratory symptoms, including shortness of breath and chest pain or tightness. Other studies have identified cognitive issues, or "brain fog."
Although severe infection is more likely to lead to long Covid, large numbers of people who had mild cases have also suffered from persistent symptoms. The Imperial study, which surveyed a random sample of more than half a million people from across England, found that around a quarter of the 21,454 people who had suffered a mild infection reported at least one symptom lasting 12 weeks or more. Those who had suffered severe infection had even higher odds of experiencing at least one persistent symptom, around half. The study, published on the MedRxiv preprint server, hasn't yet been peer reviewed.
Long Covid has raised alarm bells for its tendency to strike the young in a way that severe illness and death haven't. The Imperial study found that among those aged 18 to 24, about 30% of those who had knowinglycaught Covid-19 reported at least one symptom lasting 12 weeks or longer.
Harry Boby, a 23-year-old former member of the British judo team, worked out at the gym five times a week before coming down with a mild Covid-19 infection in September.Now, a few pull-ups can floor him for days.
"I still don't feel myself," said Mr. Boby, adding that even mild exertion can trigger "bone-crushing fatigue." He has also suffered neurological issues ranging from memory loss to episodes where he feels paranoid and sometimes tearful.
He has twice been on sick leave due to his symptoms, for around three months each time.
Researchers suspect that long Covid likely comprises several overlapping conditions, with different causes, and several large studies are under way to try to pin some of those down. Among the leading theories are that the virus triggers some kind of autoimmune condition, that it causes lasting physical damage to various organs, and that the virus lingers in the body long after infection.
There is no proven treatment for long Covid, although researchers in the U.K. are embarking on clinical trials to establish whether widely available anti-inflammatory drugs such as aspirin, gout treatment colchicine and antihistamines could help. Meanwhile, hospitals are establishing dedicated clinics to help people cope.
"I often tell patients there's nota magic bullet that's going to cure them," said Louise King, a medical director at a Covid recovery clinic run by the University of North Carolina at Chapel Hill. "We just don't know that much about it."” [1]

1.    Scientists Investigate Mystery of Long Covid. Roland, Denise. Wall Street Journal, Eastern edition; New York, N.Y. [New York, N.Y]24 July 2021: A.1.