MaineHealth has received a large grant from the National Institutes of Health to study long COVID and its causes.
Dr. Cliff Rosen, senior scientist at MaineHealth Institute for Research, will study whether the virus that causes COVID remains hidden in the fat tissue of patients with long COVID. The institute recently won an $802,000 award from the National Institutes of Health for the study, which is scheduled to start in May 2023. Credit: Courtesy of the MaineHealth Institute for Research

Despite MaineHealth closing its long COVID clinic in January, the health system’s research arm is receiving national attention for its work on the virus, recently winning a second federal grant to study potential causes.

The MaineHealth Institute for Research in Scarborough will collaborate with research centers in Kentucky and Louisiana to study whether the virus that causes COVID-19 remains hidden in the fat tissue of patients who have long COVID, stressing their immune systems. The work is part of a National Institutes of Health RECOVER study on COVID-19.


Long COVID symptoms include difficulty breathing, brain fog, joint pain and a tight chest and may occur continuously or in spurts after people contract the virus. But the condition is only starting to be understood, and some have reported serious symptoms that make everyday life challenging.

More than 40 percent of adults in the United States have reported having COVID-19, and nearly 1 in 5 of them were still having symptoms of long COVID in the middle of 2022, according to the U.S. Centers for Disease Control and Prevention. The share of Americans reporting symptoms has dropped since last year, but researchers are still on guard.

MaineHealth has received a large grant from the National Institutes of Health to study long COVID and its causes.
SARS-CoV-2 (small red entities), the virus that causes COVID-19, can infect fat tissue, which contains many cell types: fat cells are yellow, macrophages purple, and other immune cells blue. Credit: Courtesy of Dr. Catherine Blish / Stanford University

“We still don’t know what causes long COVID,” said Dr. Cliff Rosen, senior scientist at the MaineHealth Institute for Research. “If we can prove that the virus persists in the fat tissue of patients with long COVID, we can start targeting treatments that impact that part of the body.”

The $802,000 grant is good news to Marnie MacLean, who has had long COVID since getting the virus last June. MacLean, owner of the Moose Tree Media video production company in Portland, worried when the clinic closed, because it was the only place able to help her with exercises to relieve shortness of breath and tight chest and be more comfortable at work.

“I’m glad MaineHealth is getting money to study it,” she said. “But I wish they were still able to offer boots-on-the-ground care for long COVID patients, because that definitely helped me get on the road to recovery.”

She’s not alone. MacLean said she had to wait five months to get an appointment at the clinic. Rosen, who was against the clinic’s closure, said he hopes the long COVID research might help attract the resources to rebuild the clinic to treat a broader variety of symptoms.

MaineHealth has received a large grant from the National Institutes of Health to study long COVID and its causes.
Marnie MacLean has had long COVID since her initial bout with the virus in June 2022. The owner of video production company Moose Tree Media and former TV reporter in Maine said she is using breathing and other exercises to relieve the symptoms, which at times felt like an elephant was sitting on her chest. Credit: Courtesy of Stacie Maddox

The new, year-long study is an offshoot of an earlier RECOVER study in which the MaineHealth Institute for Research participated. It was awarded $1.5 million from the NIH in 2021 as part of a four-year nationwide study across 11 states focused on the long-term effects of COVID-19. It recruited 120 people from rural Maine to provide blood samples and answer questionnaires.

The new award will take 20 of those Maine patients and perform more intensive tests on them, including biochemical studies on blood urine and nasal swabs and biopsies of fat tissue. Rosen said he will share data with the  research partners in Kentucky and Louisiana, as well as Stanford Medicine, which published a study showing that the COVID-19 virus can infect fat tissue.

Rosen expects to start the new study in May. It will examine whether the COVID-19 virus lingers in the fat tissue of patients with long COVID and stresses their immune systems to the point of potential failure. Fat tissue itself triggers an immune response adding stress to the immune system, he said. It is not clear whether losing weight helps relieve long COVID.

These types of national studies are putting Maine research on the map, Rosen said.

“We’re extremely competitive on a national level for NIH funding,” he said. “Maine is not a Third World state anymore in terms of research.”

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Lori Valigra

Lori Valigra, senior reporter for economy and business, holds an M.S. in journalism from Boston University. She was a Knight journalism fellow at M.I.T. and has extensive international reporting experience...