To evaluate the preliminary efficacy and safety of HH-120 nasal spray in the treatment of asymptomatic or mild COVID-19.

During this study, participants will receive HH-120 nasal spray treatment for 6 consecutive days, the efficacy and safety of HH-120 will be assessed throughout the study period based on viral clearance, clinical recovery, illness severity and adverse events.

Inclusion Criteria:

• 18 to 65 years old.
• Participants with mild COVID-19 with symptom onset≤5 days or asymptomatic COVID-19.
• Participants being able and willing to provide informed consent prior to any study-specific procedure.

Exclusion Criteria:

• Participants with moderate or severe COVID-19.
• Participants within the pregnancy or breastfeeding period or plan to be pregnant during the study period.
• Participants requiring oxygen treatment (such as non-invasive ventilation, invasive mechanical ventilation, ECMO, etc.).
• Participants with nasal disease that is inconvenient or intolerant of nasal spray administration, or cannot use the nasal spray treatment.
• Participants with comorbid Malignancy or with a history of malignancy.
• Participants with active or uncontrolled systemic autoimmune disease.
• Insufficient function of key organs.
• Other reasons considered by the investigator to be unsuitable for the trial.