Introduction
Post-Acute Sequelae of SARS-CoV-2 infection (PASC), or Long COVID, affects some patients recovering from COVID-19, leading to prolonged or new medical conditions. Despite the lack of approved treatments for Long COVID, there's growing interest in the antiviral nirmatrelvir-ritonavir (Paxlovid) for mitigating these long-term effects.
Study Overview
This study analyzed electronic health records from 497,499 SARS-CoV-2 positive patients between March 1, 2022, and February 1, 2023. Among them, 165,256 were treated with Paxlovid within 5 days of infection, and 307,922 were not treated with Paxlovid or other COVID-19 treatments.
Key Findings
- Reduced Risk of Long COVID: Paxlovid treatment was associated with a reduced risk of Long COVID, with a Hazard Ratio (HR) of 0.88 and an absolute risk reduction of 2.99 events per 100 persons.
- Lower Risk of Hospitalization and Death: The treatment also significantly lowered the risk of all-cause death (HR, 0.53) and hospitalization (HR, 0.70) in the post-acute phase.
- No Benefit in Low-Risk Patients: The study found no conclusive evidence of Paxlovid reducing Long COVID risk in low-risk patients without documented risk factors for severe COVID-19 illness.
Discussion
The findings suggest that Paxlovid may significantly reduce the risk of Long COVID and other downstream consequences of acute COVID-19 infection for high-risk non-hospitalized adults. However, the lack of benefit in low-risk patients indicates limited utility of Paxlovid in this population for preventing both short-term and long-term consequences of infection.
Limitations
The study's observational nature means patients were not randomized to treatment or control groups, and residual confounding may still exist. Additionally, the study only considered incident conditions in the post-acute period and relied on structured information in EHR, which may be incomplete.
Conclusion
This study, the largest of its kind, provides evidence that Paxlovid treatment within 5 days of SARS-CoV-2 infection is associated with reduced risk of Long COVID, post-acute hospitalization, and death among high-risk, nonhospitalized patients with COVID-19. These benefits do not extend to low-risk patients.
