The case for testing Pfizer’s Paxlovid to treat long COVID

  • Two long COVID patients recover after Paxlovid treatment
  • Side effects, safety issues should be investigated

CHICAGO, April 18 (Reuters) – Reports of two patients who found relief from long COVID after taking Pfizer Inc’s antiviral Paxlovid (PFE.N), including a researcher who tested it on her -even, provide intriguing evidence for clinical trials to help those suffering from the debilitating condition, experts and advocates say.

The researcher said her chronic fatigue symptoms, which “felt like a truck hitting me”, disappeared after taking the two-drug oral therapy.

Long COVID is an impending health crisis, estimated to affect up to 30% of people infected with the coronavirus. This can last for months, leaving many people unable to work. More than 200 symptoms have been associated with the disease, including pain, fatigue, brain fog, breathing difficulties and exhaustion after minimal physical activity.

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Dr. Steven Deeks, a professor of medicine at the University of California, San Francisco (USSF) and an expert in HIV cure research, said drug companies tend to overlook single-patient case studies. But such cases have helped spur HIV cure research, and Deeks thinks these Paxlovid cases could do the same for a long time of COVID.

“This provides very strong evidence that we need to investigate antiviral therapy in this setting as soon as possible,” Deeks said, adding that he had heard of another anecdotal case at UCSF in which symptoms of a long COVID patient disappeared after taking Paxlovid.

Scientists warn that these cases “only generate speculation” and do not prove that the drug relieved persistent symptoms. But they support a leading theory that long COVID can be caused by the virus lingering in parts of the body for months, affecting patients’ daily lives long after acute symptoms have subsided.

The best evidence to date comes from a National Institutes of Health (NIH) study, currently under peer review, in which researchers performed autopsies on 44 people who died of COVID-19 or other cause but who have been infected with COVID. They found widespread infection throughout the body, including the brain, which can last more than seven months after symptoms appear.

Paxlovid, which combines a new Pfizer pill with the older antiviral ritonavir, is currently licensed for use in the early days of COVID infection to prevent serious illness in high-risk patients.

Pfizer spokesperson Kit Longley said the company does not have lengthy COVID studies underway and did not say whether it would consider them.

The drugmaker has two large clinical trials to test whether Paxlovid can prevent initial COVID infection. This “could provide us with relevant data to inform future studies,” Longley said.

Patients who have been suffering for months are growing increasingly frustrated with the lack of pharmaceutical research for their condition.

There are currently fewer than 20 clinical trials run by individual researchers or small drugmakers testing treatments for long COVID, only a handful of which have made it past the early stages, according to a Reuters review. Read more

Diana Berrent, founder of the community advocacy group COVID Survivor Corps, lobbied the Biden administration to fund large, lengthy COVID clinical trials.

“We shouldn’t do our research based on anecdotal reports,” she said. “That’s not good enough.”


In one of the case reports, published as a preprint ahead of peer review, a previously healthy, vaccinated 47-year-old woman was infected with COVID in the summer of 2021. Most of her symptoms Acute subsided within 48 hours, but she continued with intense fatigue, brain fog, post-exercise exhaustion, insomnia, rapid heartbeat, and body aches severe enough that she could no longer work.

About six months after her initial infection, she was reinfected, likely with COVID, and many of her acute symptoms also returned. His doctor prescribed him a five-day course of Paxlovid.

On day 3, she noticed a rapid improvement in the long-lasting COVID symptoms. “She’s back to normal,” said Dr. Linda Geng, co-director of Stanford Health Care’s long-running COVID clinic and author of the case report posted on Research Square.

In the second case, Lavanya Visvabharathy, 37, an immunologist working at Northwestern Medicine’s long-running COVID clinic, was infected in December 2021.

Her initial symptoms were mild, but she later suffered from chronic fatigue, headaches and trouble sleeping for four months after the infection. She also continued to test positive on rapid antigen tests, a sign of viral persistence.

Visvabharathy was aware of the NIH study and the Stanford case, and decided to try Paxlovid to see if it could clear any lingering virus. By the end of the five-day course, her fatigue and insomnia had improved and her headaches were less frequent. Two weeks after the end of the treatment, his fatigue was gone. “It’s 100% fixed,” she said.

But to prove that Paxlovid provides this kind of relief would require carefully controlled clinical trials, Visvabharathy said.

Dr. Igor Koralnik, who leads Northwestern Medicine’s clinic focused on the neurological effects of long COVID, noted the long list of widely used drugs that are affected by ritonavir and said Paxlovid “cannot be used willy-nilly. thank you”.

“Paxlovid is not a benign drug,” he said. “There should be studies.”

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Reporting by Julie Steenhuysen Editing by Michele Gershberg and Bill Berkrot

Our standards: The Thomson Reuters Trust Principles.


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