The effect of nirmatrelvir‐ritonavir on viral clearance and length of hospital stay in patients infected with SARS‐CoV‐2 omicron variants

BACKGROUND: The pandemic of coronavirus disease 2019 (COVID‐19) has caused heavy burdens on national healthcare systems. Nirmatrelvir‐ritonavir (Paxlovid) may be one of the most promising therapeutic drugs, with reports of up to 89% reduction rates in hospitalization risk and death among patients with mild‐to‐moderate COVID‐19 who are at risk of developing severe disease. However, limited studies have investigated the effects of this class of drugs on viral clearance and length of hospital stay. METHODS: In this study, we retrospectively analyzed the characteristics of patients infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and investigated the effects of oral nirmatrelvir‐ritonavir on viral clearance and length of hospital stay in mild‐to‐moderate COVID‐19 patients at high risk for progression to severe disease. RESULTS: The median SARS‐CoV‐2 negative conversion time was 16 (13–20) versus 13 (10–16) days (control group versus nirmatrelvir‐ritonavir group, p < 0.001), the median length of hospital stay was 13 (10–16) versus 12 (13–14) days (control group versus nirmatrelvir‐ritonavir group, p = 0.01), and the SARS‐CoV‐2 negative conversion time and length of hospital stay were significantly shorter in the nirmatrelvir‐ritonavir group than in the control group. When controlling for hypertension, chronic kidney disease, severity status of COVID‐19, use of antibiotic agent, and COVID‐19 vaccine received, multiple stepwise linear regression analysis showed that nirmatrelvir‐ritonavir treatment was negatively associated with the SARS‐CoV‐2 negative conversion time and length of hospital stay. CONCLUSION: Nirmatrelvir‐ritonavir reduces the viral clearance time and length of hospital stay in hospitalized patients with COVID‐19. Nirmatrelvir‐ritonavir might be a promising drug to reduce the virus load and the heavy burden of healthcare systems.