What the study found
The study found that oral nirmatrelvir-ritonavir did not reduce hospitalization or death among vaccinated higher-risk outpatients with SARS-CoV-2 infection. In one substudy, the treatment reduced viral load by the end of treatment.
Why the authors say this matters
The authors conclude that the treatment did not lower the risk of hospitalization or death in vaccinated higher-risk participants. The study suggests that its effect in people who have been vaccinated, infected naturally, or both had been unclear before these trials.
What the researchers tested
The main outcome was hospitalization or death from any cause within 28 days after randomization. A substudy involving 634 participants measured viral load.
What worked and what didn't
Serious adverse events were reported in 9 participants in PANORAMIC and 4 participants in CanTreatCOVID. In the substudy, viral load was reduced by the end of treatment with nirmatrelvir-ritonavir.
What to keep in mind
The trials were open-label, so participants and researchers knew which treatment was given. The abstract does not provide additional limitations beyond the low number of hospitalization or death events and the wide credible interval in CanTreatCOVID.
Key points
- Nirmatrelvir-ritonavir did not reduce hospitalization or death in vaccinated higher-risk outpatients.
- Two open-label trials were conducted: PANORAMIC in the U.K. and CanTreatCOVID in Canada.
- Participants were adults in the community with SARS-CoV-2 infection and symptoms for 5 days or less.
- A substudy found reduced viral load by the end of treatment.
- Serious adverse events were reported in both trials.
Disclosure
- Research title:
- Nirmatrelvir-ritonavir did not lower hospitalization or death
- Authors:
- Christopher C. Butler, Andrew Pinto, Victoria Harris, Jane Holmes, Najib M. Rahman, Lucy Cureton, Gail Hayward, Duncan B. Richards, David M. Lowe, Joseph F. Standing, Judith Breuer, Kerenza Hood, May Ee Png, Stavros Petrou, Jienchi Dorward, Mahendra G. Patel, Nicholas P.B. Thomas, Philip Evans, Nigel D. Hart, B Jani, Banafshe Hosseini, Srinivas Murthy, Kerry McBrien, Amanda Condon, Emily G. McDonald, Peter Daley, Michelle Greiver, Bruno R. da Costa, Peter Selby, Peter Jüni, T Lee, Haolun Shi, Michelle A. Detry, Christina Saunders, Mark Fitzgerald, Nicholas Berry, Benjamin R. Saville, Saye Khoo, Jonathan S. Nguyen-Van-Tam, F.D. Richard Hobbs, Ly-Mee Yu, Paul Little
- Institutions:
- 3M (United States), 3M (United States), 3M (United States), 3M (United States), 3M (United States), Berry & Associates (United States), Berry & Associates (United States), Berry & Associates (United States), Berry & Associates (United States), Berry & Associates (United States), Cardiff University, Centre for the AIDS Programme of Research in South Africa, Health Solutions (Sweden), Health Solutions (Sweden), Institute of Infection and Immunity, Institute of Infection and Immunity, McGill University, McGill University, McGill University Health Centre, McGill University Health Centre, Memorial University of Newfoundland, National Institute for Health and Care Excellence, National Institute for Health and Care Excellence, National Institute for Health and Care Research, NIHR Southampton Biomedical Research Centre, North York General Hospital, Nuffield Orthopaedic Centre, Orion Corporation (United Kingdom), Queen's University Belfast, Royal College of General Practitioners, Science Oxford, Simon Fraser University, St Michael's Hospital, St Michael's Hospital, St. Michael's Hospital, University College London, University College London, University College London, University of British Columbia, University of Calgary, University of Cambridge, University of Exeter, University of Glasgow, University of Liverpool, University of Manitoba, University of Nottingham, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Oxford, University of Southampton, University of Toronto, University of Toronto, University of Toronto, University of Toronto, University of Toronto, University of Toronto, Vanderbilt University
- Publication date:
- 2026-04-22
- OpenAlex record:
- View
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