There's been a lot of hope that early antiviral therapy will prevent long COVID
In the spring of 2022, a small but telling cluster of cases emerged from a University of California, San Francisco research trial, suggesting that Paxlovid — an antiviral developed to blunt acute COVID-19 — might also offer relief to those trapped in the prolonged suffering of long COVID. The condition, which shadows roughly 30 percent of those infected, has resisted easy explanation and left millions unable to work or live fully. These cases did not constitute proof, but they carried the weight of a question that medicine could no longer afford to leave unanswered: what will it take to fund the trials that might finally provide one?
- Long COVID quietly disables millions — stealing energy, clarity, and livelihood from people who never fully recovered from an infection the world declared survivable.
- Three new UCSF case studies added fresh urgency to scattered anecdotal reports, suggesting Paxlovid may ease long COVID symptoms in ways that demand serious scientific scrutiny.
- One patient's relapse after stopping the drug raised a harder question: even if antivirals help, they may not protect everyone, and the window for intervention may be narrow.
- Researchers are calling loudly for randomized clinical trials, but the path forward is blocked less by doubt than by dollars — federal funding and Pfizer's commitment remain uncertain.
- Pfizer, whose drug sits at the center of the hypothesis, had no long COVID studies underway at the time, offering only a watchful posture while the evidence quietly accumulated.
In May 2022, UCSF researchers presented three new case studies of long COVID patients who reported meaningful symptom relief after taking Paxlovid, Pfizer's oral antiviral. The cases added weight to earlier anecdotal hints and sharpened the argument that formal clinical trials were not just warranted — they were overdue.
Long COVID remains one of medicine's most confounding challenges. It develops in roughly 30 percent of those infected with the coronavirus, regardless of initial illness severity, and can persist for months with symptoms ranging from crushing fatigue and brain fog to chronic pain and shortness of breath. For many, it has meant leaving the workforce entirely.
Dr. Michael Peluso and his UCSF team documented the three patients — all vaccinated, all in their 40s — through the institution's LIINC long COVID research trial. Two reported substantial improvement after accessing Paxlovid. A third took the drug for an acute infection, improved, then relapsed after stopping it and went on to develop long COVID. The pattern was suggestive but not conclusive. Peluso noted that while early antiviral therapy holds promise for prevention, this case showed it would not work universally.
The researchers' call was clear: move beyond anecdote and into rigorous, randomized trials. But the obstacle was funding. The NIH and Pfizer's own support would be essential, and at the time, Pfizer had no long COVID studies underway. Senior author Dr. Steven Deeks put it plainly — the evidence now justified designing and implementing controlled studies of antiviral therapies. Whether the resources and institutional will would follow remained the open question.
In May 2022, researchers at the University of California, San Francisco presented three new case studies of long COVID patients who reported substantial improvement in their symptoms after taking Paxlovid, Pfizer's oral antiviral medication. The cases arrived as fresh evidence that a formal, systematic study of the drug's potential against the condition was overdue—and increasingly urgent.
Long COVID remains one of medicine's stubborn puzzles. The condition develops in roughly 30 percent of people infected with the coronavirus, striking both those who had mild illness and those who were severely sick, including children. It can persist for months, sometimes longer, producing a constellation of debilitating symptoms: exhaustion that doesn't lift with rest, a racing heartbeat, difficulty breathing, chronic pain, cognitive fog so thick it impairs work and daily function, and muscle weakness. For many, the condition has proven severe enough to keep them out of the workforce entirely. Yet despite its prevalence and impact, the underlying mechanisms remain poorly understood.
Dr. Michael Peluso and his team at UCSF documented three patients, all in their 40s and previously vaccinated, who were enrolled in the institution's long COVID research trial called LIINC. In two of the cases, patients gained access to Paxlovid and reported that their long COVID symptoms improved substantially. The third patient received the drug to treat an acute COVID infection. His symptoms initially improved, but rebounded shortly after he stopped taking it, and he subsequently developed long COVID. The pattern suggested something worth investigating further: that early antiviral therapy might prevent the condition from taking hold, though Peluso cautioned the evidence was not yet conclusive. "There's been a lot of hope that early antiviral therapy, in addition to preventing severe COVID, will prevent long COVID," he said. "And that might be true, but this case suggests that it won't be true 100% of the time."
These three cases were not the first hints that Paxlovid might help long COVID patients. Earlier reports had already suggested the possibility. But they were significant enough to strengthen the argument that researchers needed to move beyond anecdote and into rigorous, randomized clinical trials—the gold standard for determining whether a treatment actually works. "It provides evidence that we really need to study this soon, and systematically, which means randomized trials," Peluso said.
The barrier, however, was not scientific uncertainty but practical constraint: money. Conducting such a trial would require funding from federal agencies like the National Institutes of Health, as well as support from Pfizer itself. At the time of the report, Pfizer had no long COVID studies underway. A company spokesman, Kit Longley, said the drugmaker was monitoring data from its ongoing clinical studies and watching real-world evidence, and might explore the issue further. Dr. Steven Deeks, a senior author on the UCSF study, was more direct about what the accumulating evidence demanded: "Collectively, there is now ample rationale to design and implement prospective controlled studies of antiviral therapies, including Paxlovid."
The question hanging over the research was whether the resources and will would materialize to answer it.
Citas Notables
It provides evidence that we really need to study this soon, and systematically, which means randomized trials.— Dr. Michael Peluso, UCSF researcher
Collectively, there is now ample rationale to design and implement prospective controlled studies of antiviral therapies, including Paxlovid.— Dr. Steven Deeks, UCSF
La Conversación del Hearth Otra perspectiva de la historia
Why does long COVID matter so much right now? It sounds like a lingering condition, but is it really that widespread?
It affects roughly one in three people who've had COVID. That's millions of people globally. And it's not just lingering fatigue—it's severe enough that people can't work, can't think clearly, can't exercise. It's a real disability for many.
So if Paxlovid is already approved and available, why can't doctors just prescribe it for long COVID patients now?
Because it's only authorized for treating acute COVID early on—within the first few days of infection. Using it for long COVID would be off-label, and without clinical trials showing it actually works for that condition, there's no evidence base. Doctors need proof.
But these three cases show improvement. Isn't that enough?
Three cases are suggestive, but they're not proof. One patient even rebounded after stopping the drug. You need hundreds of people in a randomized trial to know if the improvement is real or just coincidence. That's what the researchers are asking for.
What's stopping them from running that trial?
Money, mainly. The NIH would need to fund it, and Pfizer would need to cooperate. At the time of this report, neither had committed to it. It's a gap between what the science suggests might work and what the system is willing to invest in.
So patients with long COVID are just waiting?
Yes. Some are trying Paxlovid anyway, off-label, hoping it helps. But without a trial, we won't know systematically whether it's worth the effort or the cost.