SA55 Novel Coronavirus Broad-spectrum Neutralizing Antibody Nasal Spray in Health People

Inclusion Criteria: * Male or female aged 18-65 on the day of enrollment; * Overall good health condition, with no significant abnormalities during screening and/or pre medication physical examinations; * Male subjects weighing ≥ 50.0kg; Female subjects with a weight of ≥ 45.0kg and a BMI between 18.0-28.0kg/m2 (including boundary values); * The subjects (males and females with fertility potential) and their sexual partners have no fertility plan from 4 weeks before screening to 3 months after the last administration of the investigational drug, voluntarily take effective contraceptive measures, and have no plans to donate sperm or eggs; * Volunteer to participate in the experiment, cooperate with the visit, and sign an informed consent form before the start of the study. Exclusion Criteria: * Individuals who are known to be allergic to the investigational drug, any component in the preparation, or other similar drugs; * Individuals with a history of severe allergies or sensitivity to inhaled allergens, including but not limited to allergic rhinitis, bronchial asthma, etc; * Previous history of sinus and septum surgery or radiotherapy; * Patients with nasal diseases that may affect the deposition/absorption of drugs in the nose (such as narrowing of the nasal vestibule, severe deviation, perforation, ulcer of the nasal septum, thickening, pallor, edema, erosion of the nasal mucosa, hypertrophy and atrophy of the nasal wings, accumulation of fluid and pus in the nasal cavit…