Effectiveness and Safety of Oral Azvudine for Elderly Hospitalized Patients With COVID‐19: A Multicenter, Retrospective, Real‐World Study - Ranran Sun; Haiyu Wang; Junyi Sun; Mengzhao Yang; Shixi Zhang; Xinjun Hu; Bo Yu; Zhan Song; Na Han; Hong Luo; Ming Cheng; Guangming Li; et al. (Advanced Science, 2025)