A Clinical Study of the Efficacy of Leritrelvir Tablets for Hospitalized Patients with Mild to Severe COVID-19

INTERVENTION: Test group:Leritrelvir Tablets ;Control group:Placebo tablets; CONDITION: Coronavirus disease 2019,COVID‐19 PRIMARY OUTCOME: Incidence of disease progression; SECONDARY OUTCOME: Duration of recovery from clinical symptoms;Symptom recovery rate;Proportion of clinical staging progression;All‐cause mortality;Proportion of subjects enrolled in ICU for treatment;Length of hospitalization;First Time of SARS‐CoV‐2 virus nucleic acid turning negative;Rate of nucleic acid turning negative;Change in RNA load from baseline; INCLUSION CRITERIA: 1. sign the informed consent form before the study, and fully understand the study content, process and possible adverse reactions; 2. age = 18 years (inclusive), gender not limited; 3. symptoms: at least 1 of the following 11 symptoms: nasal congestion or runny nose, sore throat, shortness of breath or dyspnea, cough, muscle or body pain, headache, chills, fever, nausea, vomiting, diarrhea. 4. Ct value = 30 for novel coronavirus nucleic acid test (QPCR, Ct value = 30 for ORF1ab gene or N gene); 5. Inpatients with mild or moderate novel coronavirus infection confirmed by nasopharyngeal swab test within 120 h prior to enrollment and without any high risk factors; 6. inpatients with mild or moderate novel coronavirus infection with any of the high‐risk risk factors and with onset (at least one of the 11 symptoms) for more than 5 days (not included); 7. Inpatients with heavy novel coronavirus infection. In acordance with any of the following: 1) respi