CATEGORY: IMMUNE HEALTH
The antiviral so many long COVID patients have pinned hopes on didn’t help them. In an NIH trial of 959 adults whose symptoms had dragged on for months, both a 15-day and a 25-day course of Paxlovid left brain fog, racing hearts and exercise intolerance exactly where placebo left them.1 Every group improved a little over six months. The drug added nothing to that.
The Leftover-Virus Theory Got Its Test
One leading idea holds that long COVID persists because fragments of the virus linger in the body. If that’s right, a longer run of an antiviral should flush them out and ease symptoms. The RECOVER-VITAL trial put the idea on trial directly. Participants had cognitive trouble, heart-rate and dizziness problems, or exercise intolerance lasting at least twelve weeks after infection. Each took Paxlovid for 15 days, Paxlovid for 25 days, or matching placebo pills, far longer than the usual course for a fresh infection. Nobody knew who was swallowing the real thing, doctors included. Symptom questionnaires at 90 days were the main measure, with follow-up out to six months. The answer came back flat. Scores moved by the same small amount in every arm, across all three symptom groups.1 The treatment was at least safe: no deaths, and serious problems in about 4% of participants either way.
Two Trials, Same Verdict
There’s a second data point. A smaller Stanford trial tested a 15-day course in 155 adults with long COVID and also found no benefit over placebo.2 Two randomized tests, run independently, now agree. For the millions of people living with long COVID, that’s a hard answer, and clinics still have little that works to offer them. It’s an answer all the same. Anyone weighing an off-label course of this drug for lingering symptoms now knows what the best available evidence says: the virus-flushing approach, at these doses and durations, didn’t move the needle.
Key Takeaways
- Paxlovid didn’t relieve long COVID in the NIH’s RECOVER-VITAL trial. Cognitive, heart-rate and exercise symptoms improved no more on 15 or 25 days of the drug than on placebo.
- A separate Stanford trial reached the same conclusion in 2024, so the finding now rests on two independent randomized tests.
- The trial was built to test whether leftover virus drives long COVID. Clearing that virus harder did nothing, which weakens the theory without fully closing it.
References
- Baden LR, Shah NS, Liu STH, et al. Nirmatrelvir–ritonavir targeting viral persistence in post-COVID-19 condition (Long COVID) in the USA (RECOVER-VITAL): a randomised, double-blind, placebo-controlled, phase 2 trial. Lancet Infect Dis. 2026; online August 31; doi:10.1016/S1473-3099(26)00406-8. link
- Geng LN, Bonilla H, Hedlin H, et al. Nirmatrelvir-Ritonavir and Symptoms in Adults With Postacute Sequelae of SARS-CoV-2 Infection: The STOP-PASC Randomized Clinical Trial. JAMA Intern Med. 2024;184(9):1024–1034. link