A Key to Long Covid Is Virus Lingering in the Body, Scientists Say

Virus remaining in some people’s bodies for a long time may be causing longer-term complications, recent research suggests

Authors:  Sumathi Reddy Sept. 8, 2022 The Wall Street Journal

The virus that causes Covid-19 can remain in some people’s bodies for a long time.  A growing number of scientists think that lingering virus is a root cause of long Covid.

New research has found the spike protein of the SARS-CoV-2 virus in the blood of long Covid patients up to a year after infection but not in people who have fully recovered from Covid. Virus has also been found in tissues including the brain, lungs, and lining of the gut, according to scientists and studies 

The findings suggest that leftover reservoirs of virus could be provoking the immune system in some people, causing complications such as blood clots and inflammation, which may fuel certain long Covid symptoms, scientists say. 

A group of scientists and doctors are joining forces to focus research on viral persistence and aim to raise $100 million to further the search for treatments. Called the Long Covid Research Initiative, the group is run by the PolyBio Research Foundation, a Mercer Island, Wash., based nonprofit focused on complex chronic inflammatory diseases. 

“We really want to understand what’s at the root of [long Covid] and we want to focus on that,” says Amy Proal, a microbiologist at PolyBio and the initiative’s chief scientific officer. Dr. Proal has devoted her career to researching chronic infections after developing myalgic encephalomyelitis/chronic fatigue syndrome, an illness that shares similar symptoms with long Covid, in her 20s.  She has mostly recovered now but has symptoms she manages.

Three long Covid patients, frustrated at the lack of answers and treatments, have helped connect researchers. 

“Long Covid is this really incredible emergency,” says Henry Scott-Green, one of the patients, a 28-year-old in London who says brain fog, extreme fatigue and other debilitating long Covid symptoms prevented him from resuming full-time work as a product manager, though he plans to return soon. “We’re really trying to run really efficiently and cut out as many layers of bureaucracy as possible.”

So far, the group says it has received a pledge of $15 million from Balvi, an investment and direct giving fund established by Vitalik Buterin, the co-creator of the cryptocurrency platform Ethereum. een says debilitating long Covid symptoms have prevented him from resuming full-time work.

Among the strongest evidence of viral persistence in long Covid patients is a new study by Harvard researchers published Friday in the journal of Clinical Infectious Diseases. Researchers detected the spike protein of the SARS-CoV-2 virus in a large majority of 37 long Covid patients in the study and found it in none of 26 patients in a control group.

Patients’ blood was analyzed up to a year after initial infection, says David R. Walt, a professor of pathology at Brigham and Women’s Hospital in Boston and Harvard Medical School and lead researcher of the study. Dr. Walt isn’t currently involved with the long Covid initiative. 

A year after infection, some patients had levels of viral spike protein that were as high as they did earlier in their illness, Dr. Walt says. Such levels long after initial infection suggest that a reservoir of active virus is continuing to produce the spike protein because the spike protein typically doesn’t have a long lifetimehe adds.

Dr. Walt plans to test antivirals such as Paxlovid or remdesivir to see if the drugs help clear the virus and eliminate spike protein from the blood.  He says it’s possible that for some people, the normal course of medication isn’t enough to clear the virus. Such cases may require “a much longer exposure to these antivirals to fully clear,” says Dr. Walt.

One of the research group’s goals is to find a way for people to identify whether they continue to have the virus in their bodies. There is no easy way to determine this now. 

Long Covid patients experience such a wide range of long-term symptoms that scientists think there is likely more than one cause, however. Some cases may be fueled by organ damage, for instance. 

Yet consensus is growing around the idea that lingering virus plays a significant role in long Covid. Preliminary research from immunologist Akiko Iwasaki’s laboratory at Yale University documented T or B cell activity in long Covid patients’ blood, suggesting that patients’ immune systems are continuing to react to virus in their bodies. Dr. Iwasaki is a member of the new initiative. 

In a 58-person study published in the Annals of Neurology in March, University of California, San Francisco researchers also found SARS-CoV-2 proteins circulating in particles in long Covid patients’ blood, especially in those with symptoms such as fatigue and trouble concentrating.

Now, the group is completing a study using imaging techniques and tissue biopsies to detect persistent virus or reactivation of other viruses in tissue. It also is looking at T-cell immune responses in tissues and whether they correlate with symptoms. 

Some people may harbor the virus and don’t have long-term symptoms, says Timothy Henrich, an associate professor of medicine at UCSF involved with the study and a member of the long Covid initiative. For others, lingering virus may produce problems.

“I think there’s a real amount of mounting evidence that really suggests that there is persistent virus in some people,” says Dr. Henrich.

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