* 1.positive sars-cov-2 antigen during the screening period. 2.history of sars, mers, covid-19 or known asymptomatic sars-cov-2 infection within 6 months prior to screening. 3.fever (axillary temperature ≥37.3 ℃) within 72 hours prior to vaccination. 4.history of severe allergy to any component of the experimental vaccine, including adjuvant components (squalene, alpha-tocopherol, and polysorbate 80, etc.), such as anaphylaxis, anaphylactic laryngeal edema, anaphylactic purpura, thrombocytopenic purpura, local anaphylactic necrotizing reaction (arthus reaction); or previous history of severe side effects of any vaccine or drug, such as: allergy, urticaria, skin eczema, dyspnea, angioneurotic edema, etc. 5.currently suffering from acute infectious diseases or in the active stage of chronic infectious diseases, including but not limited to hepatitis b, hepatitis c. 6.current cancer, immune disorders (e.g., human immunodeficiency virus \[hiv\] infection, systemic lupus erythematosus, rheumatoid arthritis, absence of spleen or splenectomy, and other immune disorders that the investigator believes may have an impact on immune response), etc.; current other serious chronic diseases such as unstably controlled hypertension, asthma, heart disease, diabetes, liver or kidney disease, thyroid disease, hematologic system disorders (coagulation disorders or bleeding tendency), neurological/psychiatric disorders such as convulsions, epilepsy, etc. 7.undergoing anti-tuberculosis treatment. 8.prolonged (defined as more than 14 days) use of immunosuppressive or other immunomodulatory drugs, anti-allergy therapy, or cytotoxic therapy within 6 months prior to the vaccine. inhaled/nebulized, intra-articular, intradural, or topical (skin or eyes) corticosteroids are permitted. topical doses should not exceed the recommended dose of the drug instructions. 9.have received blood products within 3 months prior to enrollment or plan to receive them during the study period. 10.participants who have received any other investigational product within 1 month prior to enrollment or intent to receive other investigational products during the study period. 11.received an inactivated vaccine or protein vaccine within 14 days prior to enrollment, or a live attenuated vaccine or adenovirus vector vaccine within 1 month, or intent to receive any other vaccine (except seasonal influenza vaccine or vaccine requiring emergency vaccination) during the study period. participants deemed unsuitable for participation in this study based on the investigator's assessment.

* 1.positive sars-cov-2 antigen during the screening period. 2.history of sars, mers, covid-19 or known asymptomatic sars-cov-2 infection within 6 months prior to screening. 3.fever (axillary temperature ≥37.3 ℃) within 72 hours prior to vaccination. 4.history of severe allergy to any component of the experimental vaccine, including adjuvant components (squalene, alpha-tocopherol, and polysorbate 80, etc.), such as anaphylaxis, anaphylactic laryngeal edema, anaphylactic purpura, thrombocytopenic purpura, local anaphylactic necrotizing reaction (arthus reaction); or previous history of severe side effects of any vaccine or drug, such as: allergy, urticaria, skin eczema, dyspnea, angioneurotic edema, etc. 5.currently suffering from acute infectious diseases or in the active stage of chronic infectious diseases, including but not limited to hepatitis b, hepatitis c. 6.current cancer, immune disorders (e.g., human immunodeficiency virus \[hiv\] infection, systemic lupus erythematosus, rheumatoid arthritis, absence of spleen or splenectomy, and other immune disorders that the investigator believes may have an impact on immune response), etc.; current other serious chronic diseases such as unstably controlled hypertension, asthma, heart disease, diabetes, liver or kidney disease, thyroid disease, hematologic system disorders (coagulation disorders or bleeding tendency), neurological/psychiatric disorders such as convulsions, epilepsy, etc. 7.undergoing anti-tuberculosis treatment. 8.prolonged (defined as more than 14 days) use of immunosuppressive or other immunomodulatory drugs, anti-allergy therapy, or cytotoxic therapy within 6 months prior to the vaccine. inhaled/nebulized, intra-articular, intradural, or topical (skin or eyes) corticosteroids are permitted. topical doses should not exceed the recommended dose of the drug instructions. 9.have received blood products within 3 months prior to enrollment or plan to receive them during the study period. 10.participants who have received any other investigational product within 1 month prior to enrollment or intent to receive other investigational products during the study period. 11.received an inactivated vaccine or protein vaccine within 14 days prior to enrollment, or a live attenuated vaccine or adenovirus vector vaccine within 1 month, or intent to receive any other vaccine (except seasonal influenza vaccine or vaccine requiring emergency vaccination) during the study period. participants deemed unsuitable for participation in this study based on the investigator's assessment.

1.positive sars-cov-2 antigen during the screening period. 2.history of sars, mers, covid-19 or known asymptomatic sars-cov-2 infection within 6 months prior to screening. 3.fever (axillary temperature ≥37.3 ℃) within 72 hours prior to vaccination. 4.history of severe allergy to any component of the experimental vaccine, including adjuvant components (squalene, alpha-tocopherol, and polysorbate 80, etc.), such as anaphylaxis, anaphylactic laryngeal edema, anaphylactic purpura, thrombocytopenic purpura, local anaphylactic necrotizing reaction (arthus reaction); or previous history of severe side effects of any vaccine or drug, such as: allergy, urticaria, skin eczema, dyspnea, angioneurotic edema, etc. 5.currently suffering from acute infectious diseases or in the active stage of chronic infectious diseases, including but not limited to hepatitis b, hepatitis c. 6.current cancer, immune disorders (e.g., human immunodeficiency virus [hiv] infection, systemic lupus erythematosus, rheumatoid arthritis, absence of spleen or splenectomy, and other immune disorders that the investigator believes may have an impact on immune response), etc.; current other serious chronic diseases such as unstably controlled hypertension, asthma, heart disease, diabetes, liver or kidney disease, thyroid disease, hematologic system disorders (coagulation disorders or bleeding tendency), neurological/psychiatric disorders such as convulsions, epilepsy, etc. 7.undergoing anti-tuberculosis treatment. 8.prolonged (defined as more than 14 days) use of immunosuppressive or other immunomodulatory drugs, anti-allergy therapy, or cytotoxic therapy within 6 months prior to the vaccine. inhaled/nebulized, intra-articular, intradural, or topical (skin or eyes) corticosteroids are permitted. topical doses should not exceed the recommended dose of the drug instructions. 9.have received blood products within 3 months prior to enrollment or plan to receive them during the study period. 10.participants who have received any other investigational product within 1 month prior to enrollment or intent to receive other investigational products during the study period. 11.received an inactivated vaccine or protein vaccine within 14 days prior to enrollment, or a live attenuated vaccine or adenovirus vector vaccine within 1 month, or intent to receive any other vaccine (except seasonal influenza vaccine or vaccine requiring emergency vaccination) during the study period. participants deemed unsuitable for participation in this study based on the investigator's assessment.

1.positive sars-cov-2 antigen during the screening period. 2.history of sars, mers, covid-19 or known asymptomatic sars-cov-2 infection within 6 months prior to screening. 3.fever (axillary temperature ≥37.3 ℃) within 72 hours prior to vaccination. 4.history of severe allergy to any component of the experimental vaccine, including adjuvant components (squalene, alpha-tocopherol, and polysorbate 80, etc.), such as anaphylaxis, anaphylactic laryngeal edema, anaphylactic purpura, thrombocytopenic purpura, local anaphylactic necrotizing reaction (arthus reaction); or previous history of severe side effects of any vaccine or drug, such as: allergy, urticaria, skin eczema, dyspnea, angioneurotic edema, etc. 5.currently suffering from acute infectious diseases or in the active stage of chronic infectious diseases, including but not limited to hepatitis b, hepatitis c. 6.current cancer, immune disorders (e.g., human immunodeficiency virus [hiv] infection, systemic lupus erythematosus, rheumatoid arthritis, absence of spleen or splenectomy, and other immune disorders that the investigator believes may have an impact on immune response), etc.; current other serious chronic diseases such as unstably controlled hypertension, asthma, heart disease, diabetes, liver or kidney disease, thyroid disease, hematologic system disorders (coagulation disorders or bleeding tendency), neurological/psychiatric disorders such as convulsions, epilepsy, etc. 7.undergoing anti-tuberculosis treatment. 8.prolonged (defined as more than 14 days) use of immunosuppressive or other immunomodulatory drugs, anti-allergy therapy, or cytotoxic therapy within 6 months prior to the vaccine. inhaled/nebulized, intra-articular, intradural, or topical (skin or eyes) corticosteroids are permitted. topical doses should not exceed the recommended dose of the drug instructions. 9.have received blood products within 3 months prior to enrollment or plan to receive them during the study period. 10.participants who have received any other investigational product within 1 month prior to enrollment or intent to receive other investigational products during the study period. 11.received an inactivated vaccine or protein vaccine within 14 days prior to enrollment, or a live attenuated vaccine or adenovirus vector vaccine within 1 month, or intent to receive any other vaccine (except seasonal influenza vaccine or vaccine requiring emergency vaccination) during the study period. participants deemed unsuitable for participation in this study based on the investigator's assessment.