Can Paxlovid Treat Long Term Covid? A new report suggests it may help some patients, but which patients might benefit remains unclear.
The report, published Monday in the journal Communications Medicine, describes the cases of 13 Covid patients who underwent extensive courses of the antiviral drug. The results were decidedly mixed: Nine patients reported some improvement, but only five said it lasted. Four reported no improvement.
Perhaps more than anything else, the report highlights that almost five years after the start of the pandemic, little is still known about what can help the millions of people with prolonged Covid. While some people get better on their own or with various treatments and medications, no treatment has yet proven to be widely successful.
“People with long Covid are eager for treatments that can help,” said Alison Cohen, an epidemiologist at the University of California, San Francisco, who is an author of the new report and a long-time Covid survivor herself. “There has been a lot of research, but it continues to be slow.”
Paxlovid, made by Pfizer, is seen as a tantalizing prospect because it can prevent serious illness during active Covid infections and because patients who take the five-day course during the infection are less likely to develop Covid much later.
In addition, a theory that some major cases of Covid may be caused by leftover virus in the body suggests that an antiviral drug such as Paxlovid may defeat these symptoms by wiping out the virus.
Last year, the first randomized trial of Paxlovid for long-term Covid showed no benefit. It was conducted at Stanford and involved 155 patients who received the drug or a placebo for 15 days. While taking Paxlovid for that long was found to be safe, it didn’t help patients much: Ten weeks later, the placebo and Paxlovid groups showed no significant difference in the severity of long-term Covid symptoms.
Dr. Upinder Singh, an infectious disease specialist and head of this trial, said her results and the new report mainly raised “more questions to be answered”: Could Paxlovid help if taken for more than 15 days or combined with other drugs? Does its effect vary depending on the types of symptoms or when the symptoms started?
“It’s very possible that within a long Covid there will be different types of disease,” said Dr. Singh, now chief of internal medicine at the University of Iowa. Perhaps Paxlovid or other antiviral drugs would help patients who could be clearly determined to have lingering virus in their bodies, he said.
Akiko Iwasaki, an immunologist at Yale University, said scientists should not “dismiss” the possibility of antivirals for a long period of Covid.
“If you look overall, you don’t see a difference between the placebo group, but these case reports demonstrate that there are people who really benefit, so we need to reach those people,” said Dr. Iwasaki, who is leading another randomized trial of Paxlovid, the results of which have not yet been published.
He said important next steps will be to identify biological markers in people whose long-term Covid symptoms improved with Paxlovid and to see if other antivirals help different patients.
The new report was not a clinical trial, but a collection of self-reports from 13 Covid patients around the country who had tried extended courses of Paxlovid. It is the first published case series of such patients, according to the authors, who include Dr. Michael Peluso, an infectious disease specialist at UCSF, and members of the Patient-Led Research Collaborative, a group of researchers who also have chronic Covid.
Patients’ experiences were too varied to yield a consistent trajectory, but the variety may provide clues for larger studies, the authors said.
The patients, aged 25 to 55, were infected between March 2020 and December 2022. They experienced one or more of a range of symptoms, including fatigue. gastrointestinal problems; cognitive problems such as brain fog; muscle pain; irregular heart rate; and a condition called post-exercise sickness, in which physical or mental exertion causes setbacks.
As with the Stanford trial, most patients in the new report had been vaccinated by the time they received Paxlovid. Their Paxlovid courses ranged from 7.5 days to 30 days. Most tried it to find relief from their persistent long-term Covid symptoms. two patients with long Covid received extended cycles of Paxlovid when they became reinfected with the virus.
Most patients were also taking other medications or supplements, making it difficult to determine the specific effect of the drug, Dr. Cohen said. However, some people said that Paxlovid helped them significantly.
Kate Leslie, 46, a social worker in Boulder, Colo., said she was healthy and athletic before contracting the coronavirus in March 2022. Six weeks later, she said, she felt like she had a concussion, struggling to think clearly and find words.
He developed orthostatic tachycardia syndrome, with symptoms such as irregular heart rate and blood pressure and occasional fainting. An Ultimate Frisbee player and coach, she began to experience profound fatigue and could barely lift her arms.
“It was like concrete blocks in your body,” he said. “I couldn’t get out of bed. My husband had to wash my hair, dry it and dress me.”
After an antiviral she was prescribed for a flu infection, Tamiflu, ended up relieving some of her long-term Covid symptoms, Ms. Leslie wondered if Covid-related antivirals could help even more, she said. In February 2023, he found a doctor to prescribe a 15-day course of Paxlovid.
Afterward, “I could feel my body recovering,” she said, adding, “I started to get my energy back.”
About six months later, he took another 15-day course, which again helped, he said. She estimates she can now function at about 85% of her pre-Covid level.
Ms. Leslie said, however, that some of her medical problems worsened after Paxlovid, including an immune system condition that has caused allergies. Three other patients also reported bothersome problems after taking Paxlovid, such as tingling and gastrointestinal discomfort.
Among those who perceived no benefit from the drug was Julia Moore Fogel. Dr. Vogel, 39, a senior program director at Scripps Research, was a long-distance runner before contracting the coronavirus in July 2020. She now uses a wheelchair and is largely confined to her home, she said.
She and her daughter recently moved across the country from California to live with her parents in Schaghticoke, New York. . .
Dr. Vogel, whose symptoms include fatigue, post-exercise malaise and migraines, was given a 10-day course of Paxlovid in April 2023. “It just had no effect on me,” he said.
These days she manages by carefully regulating her energy, trying to leave the house no more than once a week. Migraine medications provided some relief, she said, but other than that, “I’ve tried a lot of things and basically nothing has really helped me get better.”
Dr Cohen said the report reinforces the theory that long-term Covid has many different causes and treatments.
“A really important question is who might benefit from taking an extended course of Paxlovid and why,” he said, “and if it benefits certain symptoms, which symptoms does it benefit?”
