An Investigator-initiated, Randomized, Single-Blind, Placebo-Controlled Trial to Evaluate the Efficacy of SARS-Cov-2 Post Exposure Prophylaxis and Safety of HH-120 nasal spray

Inclusion Criteria:

• Participants aged 18 to 65 years.
• Participants who have close contact with a SARS-CoV-2 infected individual (index case) are required to be randomized within 72 hours upon close contact.
• Willing and able to provide written informed consent, or with a legal representative who can provide informed consent.

Exclusion Criteria:

• Have a history of severe allergy or hyper-sensitivity to inhaled allergen.
• Pregnant or breastfeeding women.
• Have participated, within the last 180 days prior to the screening, in a clinical study involving an investigational intervention of SARS-CoV-2 neutralizing antibody.
• Have other conditions not suitable for the study per investigator's discretion.