1. Healthy subjects aged 3 years and above, 2. By asking for a medical history and a physical examination, the researchers determined that the subjects were in good health, 3. From December 2019 to now, the subject has not been to hubei province, outside the country or in a village/community where there has been an outbreak. The subject has not been exposed to a person infected with or suspected of COVID-19, 4. Female subjects with childbearing age are not pregnant at the time of admission (negative reaction in urine pregnancy test), and are not nursing and have not fertility plan within the first 3 months after admission. Effective contraceptive measures shall be taken within 2 weeks before inclusion, 5. Subjects are able and willing to complete the study plan over follow-up period of approximately 14 months, 6. The subject or/and his/her legal guardian or trustee have the ability to understand the study procedures, voluntarily sign informed consent with informed consent, and comply with the requirements of the clinical study protocol.

1. Healthy subjects aged 3 years and above, 2. By asking for a medical history and a physical examination, the researchers determined that the subjects were in good health, 3. From December 2019 to now, the subject has not been to hubei province, outside the country or in a village/community where there has been an outbreak. The subject has not been exposed to a person infected with or suspected of COVID-19, 4. Female subjects with childbearing age are not pregnant at the time of admission (negative reaction in urine pregnancy test), and are not nursing and have not fertility plan within the first 3 months after admission. Effective contraceptive measures shall be taken within 2 weeks before inclusion, 5. Subjects are able and willing to complete the study plan over follow-up period of approximately 14 months, 6. The subject or/and his/her legal guardian or trustee have the ability to understand the study procedures, voluntarily sign informed consent with informed consent, and comply with the requirements of the clinical study protocol.