1) Subaxillary body temperature >37.0 degree C, 2) A history of close contact with patients with COVID-19 within 21 days before vaccination, 3) Those with a history of severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS), 4) Women with positive blood pregnancy test, or women in pregnancy or lactation period, 5) Smokers or those who smoked more than 5 cigarettes a day in the three months before the trial, 6) Those with a history of allergic rhinitis, 7) Subjects suffering from acute sinusitis or chronic sinusitis with acute exacerbation symptoms within 3 days before vaccination, 8) Abnormalities in the nasal cavity, such as granulomas in the nasal cavity, deviation of the nasal septum, and nasal polyps, which may affect the specimen collection or vaccination according to the clinician's judgment, 9) Those who had fever (Subaxillary body temperature = 38.0 ?) within 3 days before vaccination or had any acute disease in the past 5 days and needed systemic antibiotic or antiviral treatment (including but not limited to the use of anti-influenza virus drugs such as Tamiflu, Relenza, Symmetrel or flumadine), 10) People who suffer from severe chronic medical diseases or whose condition cannot be controlled smoothly after using drugs, such as hypertension (systolic blood pressure> 140mmHg or diastolic blood pressure> 90mmHg), diabetes, asthma, thyroid disease, etc., 11) People with immunodeficiency diseases, primary diseases of vital organs, cancer, immune diseases (including Guillain Barre syndrome, systemic lupus erythematosus, rheumatoid arthritis, no spleen or splenectomy due to any condition, and other immune diseases that researchers believe may have an impact on the immune response), etc., 12) Have received immunoglobulin and / or blood preparations within 3 months before vaccination, or plan to use them during the study period, 13) Received subunit or inactivated vaccine within 14 days before vaccination, or received live attenuated vaccine within 28 days before vaccination, 14) Those who have received influenza vaccine within 6 months before vaccination, 15) Those who have received other research drugs or vaccines within 1 month before vaccination, or plan to use other research drugs or vaccines during the study period, 16) Have received any intranasal drug treatment or nasal surgery within 7 days before vaccination, 17) long term (lasting more than 14 days) use of immunosuppressants and other immunomodulatory drugs, or systemic use of corticosteroids (topical ointment, eye drops, inhalers, etc. are allowed, but nasal spray is not included) within 6 months before vaccination, 18) Have a history of severe allergies, including those who have had serious adverse reactions from previous vaccination, such as allergies, urticaria, dyspnea, angioedema, etc., or those who are allergic to any component of the vaccine used in this trial, 19) Those who have taken aspirin, drugs containing aspirin or salicylate within 14 days before vaccination or plan to use them in this trial, 20) Those who reported having coagulation disorder or abnormal coagulation function in the past, 21) The results of blood routine, blood biochemistry, coagulation function and urine routine tests are judged by clinicians to have clinical significance, 22) The investigator judged after inquiring the subject's medical history and related physical examinations that various medical, psychological, social conditions, occupati

1) Subaxillary body temperature >37.0 degree C, 2) A history of close contact with patients with COVID-19 within 21 days before vaccination, 3) Those with a history of severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS), 4) Women with positive blood pregnancy test, or women in pregnancy or lactation period, 5) Smokers or those who smoked more than 5 cigarettes a day in the three months before the trial, 6) Those with a history of allergic rhinitis, 7) Subjects suffering from acute sinusitis or chronic sinusitis with acute exacerbation symptoms within 3 days before vaccination, 8) Abnormalities in the nasal cavity, such as granulomas in the nasal cavity, deviation of the nasal septum, and nasal polyps, which may affect the specimen collection or vaccination according to the clinician's judgment, 9) Those who had fever (Subaxillary body temperature = 38.0 ?) within 3 days before vaccination or had any acute disease in the past 5 days and needed systemic antibiotic or antiviral treatment (including but not limited to the use of anti-influenza virus drugs such as Tamiflu, Relenza, Symmetrel or flumadine), 10) People who suffer from severe chronic medical diseases or whose condition cannot be controlled smoothly after using drugs, such as hypertension (systolic blood pressure> 140mmHg or diastolic blood pressure> 90mmHg), diabetes, asthma, thyroid disease, etc., 11) People with immunodeficiency diseases, primary diseases of vital organs, cancer, immune diseases (including Guillain Barre syndrome, systemic lupus erythematosus, rheumatoid arthritis, no spleen or splenectomy due to any condition, and other immune diseases that researchers believe may have an impact on the immune response), etc., 12) Have received immunoglobulin and / or blood preparations within 3 months before vaccination, or plan to use them during the study period, 13) Received subunit or inactivated vaccine within 14 days before vaccination, or received live attenuated vaccine within 28 days before vaccination, 14) Those who have received influenza vaccine within 6 months before vaccination, 15) Those who have received other research drugs or vaccines within 1 month before vaccination, or plan to use other research drugs or vaccines during the study period, 16) Have received any intranasal drug treatment or nasal surgery within 7 days before vaccination, 17) long term (lasting more than 14 days) use of immunosuppressants and other immunomodulatory drugs, or systemic use of corticosteroids (topical ointment, eye drops, inhalers, etc. are allowed, but nasal spray is not included) within 6 months before vaccination, 18) Have a history of severe allergies, including those who have had serious adverse reactions from previous vaccination, such as allergies, urticaria, dyspnea, angioedema, etc., or those who are allergic to any component of the vaccine used in this trial, 19) Those who have taken aspirin, drugs containing aspirin or salicylate within 14 days before vaccination or plan to use them in this trial, 20) Those who reported having coagulation disorder or abnormal coagulation function in the past, 21) The results of blood routine, blood biochemistry, coagulation function and urine routine tests are judged by clinicians to have clinical significance, 22) The investigator judged after inquiring the subject's medical history and related physical examinations that various medical, psychological, social conditions, occupati