A Study of HH-120 Nasal Spray in Close Contacts of Those Diagnosed With COVID-19

Inclusion Criteria: * Male and female subjects aged 18 or above; * Caregivers of hospitalized children who are infected with SARS-CoV-2; * Negative qRT-PCR nucleic acid test result during the screening; * Willing and able to give written informed consent. Exclusion Criteria: * Those who have child-bearing plan or are unable to voluntarily take effective contraceptive measures, or plan to donate sperm/ovum during the study or within 3 months after the end of the study; * Female subjects who are positive for human chorionic gonadotropin (β-Human Chorionic Gonadotropin, β-HCG) or are breastfeeding; * Have used antiviral drugs with a therapeutic effect on COVID-19 within 3 months before screening, including various monoclonal antibodies (tixagevimab and cilgavimab, tocilizumab, ambavirumab and romisvir, Bamlanivimab, Etesevimab, Bebtelovimab, Casirivimab and imdevimab, Sotrovimab), convalescent plasma, hydroxychloroquine, Paxlovid (Nimatevir/ritonavir), Azvudine, Baricitinib, molnupiravir, remdesivir, interference drug, ribavirin, arbidol and lopinavir, etc.; (except those with the wash-out time longer than 5 half-lives); * Those who have participated in clinical trials of SARS-CoV-2 neutralizing antibodies or participated in clinical trials of other drugs within 4 weeks before screening; * Those who have a history of severe allergies or are sensitive to inhaled allergens; or are known to be sensitive to the ingredients of the study drug, other monoclonal antibody drugs, and therapeutic protein preparations (fresh or frozen plasma, human serum albumin, cytokines, interleukin, etc.) Factors, etc.) have allergies or hypersensitivity reactions; * Those who have received the COVID-19 vaccine within 2 weeks before the study drug administration or plan to receive the COVID-19 vaccine during the study; * Those who cannot tolerate with nasal spray treatment; * Any other circumstances that the researchers deemed not suitable for participating in the study.