inclusion criteria: healthy participants aged 18 years and above who have not received covid-19 vaccine. the subjects can provide with informed consent and sign informed consent form (icf). 4. the subjects are able to and willing to comply with the requirements of the clinical trial program and could complete the follow-up of the study. 5. axillary temperature ≤ 37.0℃. 6. negative igm and igg against sars-cov-2 7. with bmi between18.5 to 30.0 8. no history of epidemiological contact with covid-2019 9. have not been to medium or high risk areas in the past 21 days and have no history of departure. 10. be determined to be healthy by medical history, physical examination and clinical examination and meet the requirements for immunization of this product.

inclusion criteria: healthy participants aged 18 years and above who have not received covid-19 vaccine. the subjects can provide with informed consent and sign informed consent form (icf). 4. the subjects are able to and willing to comply with the requirements of the clinical trial program and could complete the follow-up of the study. 5. axillary temperature ≤ 37.0℃. 6. negative igm and igg against sars-cov-2 7. with bmi between18.5 to 30.0 8. no history of epidemiological contact with covid-2019 9. have not been to medium or high risk areas in the past 21 days and have no history of departure. 10. be determined to be healthy by medical history, physical examination and clinical examination and meet the requirements for immunization of this product.