Effectiveness of remdesivir-based therapy for moderate COVID-19: comparison of Omicron and other variant phases.

Remdesivir is an antiviral drug for the treatment of coronavirus disease 2019 (COVID-19), and the sustained antiviral activity against Omicron variants of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been reported. In this single-center retrospective study, we first compared the clinical effectiveness of remdesivir-based therapy between Omicron and other variant phases of moderate COVID-19 in a real-world setting. Between Dec 2020 and July 2022, a total of 406 patients with COVID-19 pneumonia were treated with remdesivir-based therapy on admission. The oxygen deterioration rate after initiation of treatment significantly decreased in the Omicron variant phase compared to the alpha and delta variant phases. In an adjusted multivariate Cox proportional hazards model, Omicron variant phase was significantly associated with delayed oxygen deterioration and early recovery from hypoxia. These favorable outcomes during the Omicron variant phase, compared to previous variant phases, might be due to the attenuation and the popularization of vaccination.