A Clinical Study to Assess Preliminary Efficacy, Safety and Tolerability of HH-120 Nasal Spray in COVID-19 Patients

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.