The patients with Omicron infection usually have fever, respiratory symptoms, tachycardia, headache, toothache, muscle soreness, physical decline, and so on, while others are asymptomatic patients. It is urgent to find drugs to improve the long-term rehabilitation of symptomatic patients with Omicron infection and decrease the duration of viral shedding in both symptomatic and asymptomatic patients. This study aims to investigate the efficacy and safety of Lianhua Qingke tablets in patients with Omicron infection. The duration of viral shedding and symptoms will be evaluated. 6-month follow-up will be performed to evaluate the effect of Lianhua Qingke on long-term rehabilitation of all symptoms induced by Omicron infection, as well as infection events.

Inclusion Criteria:

• confirmed Omicron infection by virus testing;
• ≥18 years of age;
• informed consent provided.

Exclusion Criteria:

• overt bacterial infection in the respiratory tract resulting from common pathologies, including primary immunodeficiency disease, acquired immunodeficiency syndrome, congenital respiratory malformation, congenital heart disease, gastroesophageal reflux disease, and abnormal lung development;
• asthma treated daily, chronic airway disease, respiratory bacterial infections (e.g., purulent tonsillitis), acute tracheobronchitis, sinusitis, otitis media, and further respiratory tract pathologies potentially affecting the trial's data analysis;
• common pulmonary diseases (e.g., severe pulmonary interstitial lesions and bronchiectasis) confirmed by chest CT;
• severe pneumonia requiring ventilator use;
• previous or present diseases potentially affecting trial participation or influencing study outcome, based on the investigator's judgment;
• pregnancy or lactation in women;
• participation in a clinical study in the past 3 months;
• history of allergy to ≥2 drugs or foods or known allergy to the drug's constituents.