inclusion criteria: 1. voluntarily sign the icf approved by the ethics committee before any study procedure and agree to participate in the study. 2. healthy male or female able to provide legal identity certificate and aged 18 years and older when signing the icf. 3. have not previously received any sars-cov-2 vaccine (marketed or investigational) before screening. 4. be able to communicate well with the investigator, and to understand and comply with the requirements of this clinical trial. 5. males or females of childbearing potential voluntarily take effective contraceptive methods from signing icf to 3 months after the last vaccination, including sexual abstinence or effective contraceptive measures (e.g., intrauterine or implanted contraceptive device, oral contraceptives, injected or implanted contraceptives, sustained-release topical contraceptives, intrauterine device \[iud\], condoms \[male\], diaphragm, and cervical cap).

inclusion criteria: 1. voluntarily sign the icf approved by the ethics committee before any study procedure and agree to participate in the study. 2. healthy male or female able to provide legal identity certificate and aged 18 years and older when signing the icf. 3. have not previously received any sars-cov-2 vaccine (marketed or investigational) before screening. 4. be able to communicate well with the investigator, and to understand and comply with the requirements of this clinical trial. 5. males or females of childbearing potential voluntarily take effective contraceptive methods from signing icf to 3 months after the last vaccination, including sexual abstinence or effective contraceptive measures (e.g., intrauterine or implanted contraceptive device, oral contraceptives, injected or implanted contraceptives, sustained-release topical contraceptives, intrauterine device \[iud\], condoms \[male\], diaphragm, and cervical cap).

inclusion criteria: voluntarily sign the icf approved by the ethics committee before any study procedure and agree to participate in the study. healthy male or female able to provide legal identity certificate and aged 18 years and older when signing the icf. have not previously received any sars-cov-2 vaccine (marketed or investigational) before screening. be able to communicate well with the investigator, and to understand and comply with the requirements of this clinical trial. males or females of childbearing potential voluntarily take effective contraceptive methods from signing icf to 3 months after the last vaccination, including sexual abstinence or effective contraceptive measures (e.g., intrauterine or implanted contraceptive device, oral contraceptives, injected or implanted contraceptives, sustained-release topical contraceptives, intrauterine device [iud], condoms [male], diaphragm, and cervical cap).

inclusion criteria: voluntarily sign the icf approved by the ethics committee before any study procedure and agree to participate in the study. healthy male or female able to provide legal identity certificate and aged 18 years and older when signing the icf. have not previously received any sars-cov-2 vaccine (marketed or investigational) before screening. be able to communicate well with the investigator, and to understand and comply with the requirements of this clinical trial. males or females of childbearing potential voluntarily take effective contraceptive methods from signing icf to 3 months after the last vaccination, including sexual abstinence or effective contraceptive measures (e.g., intrauterine or implanted contraceptive device, oral contraceptives, injected or implanted contraceptives, sustained-release topical contraceptives, intrauterine device [iud], condoms [male], diaphragm, and cervical cap).