Abstract
Nirmatrelvir plus ritonavir received Emergency Use Authorization for treating mild to moderate COVID-19 in high-risk patients. Its efficacy against the Omicron variant of SARS-CoV-2 remains uncertain. This retrospective cohort study assessed the effect of nirmatrelvir-ritonavir in preventing severe disease progression and long COVID symptoms after acute COVID-19 in non-hospitalized adults. SALAMA medical records from Dubai's COVID-19 healthcare centers between May 22, 2022, and April 30, 2023, were used to identify 7290 eligible patients, 9.6% of whom received nirmatrelvir-ritonavir. Treatment was associated with a notable reduction in COVID-19-related hospitalizations (adjusted hazard ratio [HR] of 0.39; 95% CI, 0.18-0.85) by day 28 of symptom onset. Moreover, nirmatrelvir-ritonavir was associated with fewer long COVID symptoms (adjusted HR of 0.42; 95% CI, 0.19-0.95). This suggests the significant effectiveness of nirmatrelvir-ritonavir against the Omicron variant, reducing both severe and long-term COVID-19 symptoms.