Long COVID: Could the mono virus or fat cells be playing roles?

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A British historian, an Italian archaeologist and an American preschool teacher have never met in person, but they share an important pandemic bond.

Plagued by eerily similar symptoms, the three women are credited with describing, naming, and helping to bring long-running COVID into the public consciousness in early 2020.

Rachel Pope from Liverpool took to Twitter in late March 2020 to describe her then-unnamed dire symptoms following a coronavirus infection. Elisa Perego in Italy first used the term “long COVID” in a tweet from May of that year. Amy Watson in Portland, Oregon, was inspired to name her Facebook support group after the trucker cap she wore, and “long hauler” soon became part of the pandemic lexicon.

Nearly three years after the pandemic began, scientists are still trying to figure out why some people stay with COVID for a long time, and why a small proportion — including the three women — have lasting symptoms.

Millions of people around the world have had long COVID, reporting various symptoms including fatigue, lung problems and brain fog and other neurological symptoms. Evidence suggests that most recover substantially within a year, but recent data show that it has contributed to more than 3,500 US deaths.

Here is some of the latest evidence:


Many studies and anecdotal evidence suggest that women are more likely than men to develop long-term COVID.

There may be biological reasons.

Women’s immune systems generally have stronger reactions to viruses, bacteria, parasites and other germs, noted Sabra Klein, a Johns Hopkins professor who studies immunity.

Women are also much more likely than men to have autoimmune diseases, in which the body mistakenly attacks its own healthy cells. Some scientists believe that the long COVID may result from an autoimmune response triggered by the virus.

Women’s bodies also tend to have more fatty tissue and emerging research suggests that the coronavirus can hide in fat after infection. Scientists are also studying whether women’s fluctuating hormone levels might increase risks.

Another possible factor: Women are more likely than men to seek health care and are often more attuned to changes in their bodies, Klein noted.

“I don’t think we should ignore this,” she said. Biology and behavior are likely at play, Klein said.

So it may not be a coincidence that it was three women who helped to lighten the long COVID.

Pope, 46, started reporting what he was feeling in March 2020: flu-like symptoms, then his lungs, heart and joints were affected. After a month she started having some “OK” days, but the symptoms persisted.

She and some sick colleagues connected with Perego on Twitter. “We started teaming up because it was literally the only place we could do this,” Pope said. “In 2020, we joked that we would get together for Christmas and have a party,” Pope said. “So obviously it went on and I think we stopped playing.”

Watson started his long truck virtual group that April. The others soon learned of this nickname and embraced it.


Several studies suggest that the ubiquitous Epstein-Barr virus may play a role in some cases of long-term COVID.

The inflammation caused by the coronavirus infection can activate the herpes virus, which remains in the body after causing an acute infection, said Dr. Timothy Henrich, a virus expert at the University of California, San Francisco.

The Epstein-Barr virus is among the most common of these herpes viruses: an estimated 90% of the US population has been infected with it. The virus can cause mononucleosis or symptoms that can be dismissed as a cold.

Henrich is among researchers who have found immune markers signaling Epstein-Barr reactivation in the blood of long-term COVID patients, particularly those with fatigue.

Not all long COVID patients have these markers. But it’s possible that Epstein-Barr is causing symptoms in those who do, though scientists say more study is needed.

Some scientists also believe that Epstein-Barr triggers chronic fatigue syndrome, a condition that has many similarities to long-standing COVID, but which is also unproven.


Obesity is a risk factor for serious COVID-19 infections, and scientists are trying to understand why.

Stanford University researchers are among those who have found evidence that the coronavirus can infect fat cells. In a recent study, they found the virus and signs of inflammation in fat tissue taken from people who died from COVID.

Laboratory tests have shown that the virus can reproduce in fatty tissue. This raises the possibility that adipose tissue could serve as a “reservoir”, potentially fueling the long COVID.

Can removing adipose tissue treat or prevent some cases of long-term COVID? It’s a tempting question, but the research is preliminary, said Dr. Catherine Blish, Stanford professor of infectious diseases and senior author of the study.

Scientists at the University of Texas Southwestern Medical Center are studying leptin, a hormone produced by fat cells that may influence the body’s immune response and promote inflammation.

They plan to study whether injections of a manufactured antibody can reduce leptin levels — and, in turn, inflammation from coronavirus infections or prolonged COVID.

“We have a good scientific basis along with some preliminary data to argue that we might be on the right track,” said Dr. Philipp Scherer.


It is estimated that about 30% of people infected with the coronavirus will develop long-term COVID, based on data from the beginning of the pandemic.

Most people who have persistent, recurring, or new symptoms after infection recover after about three months. Among those with symptoms within three months, about 15% will continue to have symptoms for at least nine more months, according to a recent study in the Journal of the American Medical Association.

Figuring out who is at risk for symptoms that last for years “is a very complicated issue,” said Dr. Lawrence Purpura, an infectious disease specialist at Columbia University.

Those with severe infections appear to be more at risk of long-term COVID, although it can also affect people with mild infections. Those whose infections cause severe lung damage, including scarring, may experience shortness of breath, coughing or fatigue for more than a year. And a smaller group of patients with mild initial COVID-19 infections may develop neurological symptoms for more than a year, including chronic fatigue and brain fog, Purpura said.

“Most patients will eventually recover,” he said. “It is important that people know this.”

It’s small consolation for the three women who helped the world recognize the long COVID.

Perego, 44, developed heart, lung and neurological problems and remains critically ill.

She knows scientists have learned a lot in a short time, but says “there’s a gap” between long COVID research and medical care.

“We need to translate scientific knowledge into better treatments and policies,” she said.

Watson, in his late 50s, says he “never had any sort of recovery.” She had severe migraines, as well as digestive, nerve and foot problems. Recently, she has developed severe anemia.

She wishes the medical community had a more organized approach to treating long-term COVID. Doctors say not knowing the underlying cause or causes makes this difficult.

“I just want my life back,” Watson said, “and it doesn’t seem like that’s possible.”


The Associated Press Department of Health and Science is supported by the Educational and Science Media Group at the Howard Hughes Medical Institute. AP is solely responsible for all content.