This is a randomized, double-blind, placebo-controlled Phase 2 study in participants over the age of 18 years with mild COVID-19. The main purpose of this study is to evaluate the effect on viral load clearance and clinical recovery, and safety of HH-120 nasal spray in participants over the age of 18 years with mild COVID-19 (according to the FDA definition, 2021).

Inclusion Criteria:

• Participants who are ≥18 years of age .
• Participants who are diagnosed with mild COVID-19 and with Laboratory confirmed of SARS-CoV-2 infection as determined by PCR or antigen test.
• Participants who agree to use highly effective methods of contraception. Women of childbearing potential (WOCBP) must have a negative urine pregnancy test result.
• Participants who are willing and able to provide written informed consent, or with a legal representative who can provide informed consent.

Exclusion Criteria:

• Have suspected or proven serious disease (cardiovascular, renal, liver systems, etc.), active bacterial, fungal, viral, or other infection (except COVID 19) that in the opinion of the Investigator could constitute a risk when taking the study intervention.
• Bronchial asthma or chronic obstructive pulmonary disease （COPD).
• Urgent or expected need for nasal high-flow oxygen therapy or positive pressure ventilation, invasive mechanical ventilation or Extracorporeal membrane oxygenation(ECMO).
• Have prior use (unless required as rescue medication) of any of the following treatments: COVID 19 investigational or Emergency Use Authorization (EUA) approved treatment, including but not limited to convalescent plasma, mAbs against SARS CoV 2, intravenous immune globulin (IVIG) (any indication), where prior use is defined as the past 30 days or less than 5 half lives of the investigational product (whichever is longer) from Screening.
• History of anaphylaxis or other significant allergy in the opinion of the PI or known allergy or hypersensitivity to any of the components of the study intervention.