* any screening hematology and/or blood biochemistry laboratory value that meets the definition of a ≥grade 1 abnormality, * (for group 1 only) confirmed sars-cov-2 diagnosis within 1 years before screening visit. * history of severe acute respiratory syndrome (sars), middle east respiratory syndrome (mers), or other coronavirus infections. * receipt of medications intended to treat covid-19 with 1 year. * history of server adverse reaction associated with a vaccine or drug and/or severe allergic reaction (e.g., anaphylaxis) to any component of the study intervention(s). * sars-cov-2 rt-pcr positive nasopharyngeal/oropharyngeal swab specimens at screening. * positive hiv test at screening. * a history or family history of convulsions, epilepsy, encephalopathy and psychosis. * malignant tumors in the active phase, malignant tumors not receiving adequate treatment, malignant tumors at potential risk of recurrence during the study period. * asplenia of functional asplenia, complete or partial splenectomy from any cause. * individuals who receive treatment with radiotherapy or immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids (if systemic corticosteroids are administered for≥14 days at a dose of ≥20 mg/day of prednisone or equivalent), e.g., for cancer or an autoimmune disease, or planned receipt throughout the study. inhaled/nebulized, intra-articular, epidural, or topical (skin or eyes) corticosteroids are permitted. * any other licensed vaccines given within 28 days prior to the investigational vaccination, or planned administration of vaccine(s) within 28 days after (full) vaccination. * receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies, form 60 days before vaccine administration, or receipt of any passive antibody therapy specific to covid-19, from 90 days before vaccine administration, or planned receipt throughout the study. * blood donation or blood loss ≥450ml within 1 month prior to enrollment or planned to donate blood during the study period. * participation in other studies involving study intervention within 28 days prior to study entry, and/or during the study. * women who are pregnant or breastfeeding. * participants deemed unsuitable for participation in this study based on the investigator's assessment. * (for group 1 only: criteria for delay of 2nd dose of vaccination) fever within 24 hours prior to the 2nd dose of vaccination (axillary body temperature ≥37.3℃/99.1°f). * (for group 1 only: criteria for delay of 2nd dose of vaccination) during treatment/recovery from illness. * (for group 1 only: criteria for delay of 2nd dose of vaccination) other conditions considered by the investigator to be unsuitable for vaccination. * (for group 1 only: criteria for termination of 2nd dose of vaccination) participants with a positive urine pregnancy or blood pregnancy test (women of childbearing age only). * (for group 1 only: criteria for termination of 2nd dose of vaccination) serious allergic reactions or serious adverse events related to vaccination (as assessed by the investigator) following a previous dose of vaccine. * (for group 1 only: criteria for termination of 2nd dose of vaccination) positive result for sars-cov-2 (positive rt-pcr test). * (for group 1 only: criteria for termination of 2nd dose of vaccination) the investigator considers inappropriate for the participants to continue participation in the study.

* any screening hematology and/or blood biochemistry laboratory value that meets the definition of a ≥grade 1 abnormality, * (for group 1 only) confirmed sars-cov-2 diagnosis within 1 years before screening visit. * history of severe acute respiratory syndrome (sars), middle east respiratory syndrome (mers), or other coronavirus infections. * receipt of medications intended to treat covid-19 with 1 year. * history of server adverse reaction associated with a vaccine or drug and/or severe allergic reaction (e.g., anaphylaxis) to any component of the study intervention(s). * sars-cov-2 rt-pcr positive nasopharyngeal/oropharyngeal swab specimens at screening. * positive hiv test at screening. * a history or family history of convulsions, epilepsy, encephalopathy and psychosis. * malignant tumors in the active phase, malignant tumors not receiving adequate treatment, malignant tumors at potential risk of recurrence during the study period. * asplenia of functional asplenia, complete or partial splenectomy from any cause. * individuals who receive treatment with radiotherapy or immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids (if systemic corticosteroids are administered for≥14 days at a dose of ≥20 mg/day of prednisone or equivalent), e.g., for cancer or an autoimmune disease, or planned receipt throughout the study. inhaled/nebulized, intra-articular, epidural, or topical (skin or eyes) corticosteroids are permitted. * any other licensed vaccines given within 28 days prior to the investigational vaccination, or planned administration of vaccine(s) within 28 days after (full) vaccination. * receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies, form 60 days before vaccine administration, or receipt of any passive antibody therapy specific to covid-19, from 90 days before vaccine administration, or planned receipt throughout the study. * blood donation or blood loss ≥450ml within 1 month prior to enrollment or planned to donate blood during the study period. * participation in other studies involving study intervention within 28 days prior to study entry, and/or during the study. * women who are pregnant or breastfeeding. * participants deemed unsuitable for participation in this study based on the investigator's assessment. * (for group 1 only: criteria for delay of 2nd dose of vaccination) fever within 24 hours prior to the 2nd dose of vaccination (axillary body temperature ≥37.3℃/99.1°f). * (for group 1 only: criteria for delay of 2nd dose of vaccination) during treatment/recovery from illness. * (for group 1 only: criteria for delay of 2nd dose of vaccination) other conditions considered by the investigator to be unsuitable for vaccination. * (for group 1 only: criteria for termination of 2nd dose of vaccination) participants with a positive urine pregnancy or blood pregnancy test (women of childbearing age only). * (for group 1 only: criteria for termination of 2nd dose of vaccination) serious allergic reactions or serious adverse events related to vaccination (as assessed by the investigator) following a previous dose of vaccine. * (for group 1 only: criteria for termination of 2nd dose of vaccination) positive result for sars-cov-2 (positive rt-pcr test). * (for group 1 only: criteria for termination of 2nd dose of vaccination) the investigator considers inappropriate for the participants to continue participation in the study.

any screening hematology and/or blood biochemistry laboratory value that meets the definition of a ≥grade 1 abnormality, (for group 1 only) confirmed sars-cov-2 diagnosis within 1 years before screening visit. history of severe acute respiratory syndrome (sars), middle east respiratory syndrome (mers), or other coronavirus infections. receipt of medications intended to treat covid-19 with 1 year. history of server adverse reaction associated with a vaccine or drug and/or severe allergic reaction (e.g., anaphylaxis) to any component of the study intervention(s). sars-cov-2 rt-pcr positive nasopharyngeal/oropharyngeal swab specimens at screening. positive hiv test at screening. a history or family history of convulsions, epilepsy, encephalopathy and psychosis. malignant tumors in the active phase, malignant tumors not receiving adequate treatment, malignant tumors at potential risk of recurrence during the study period. asplenia of functional asplenia, complete or partial splenectomy from any cause. individuals who receive treatment with radiotherapy or immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids (if systemic corticosteroids are administered for≥14 days at a dose of ≥20 mg/day of prednisone or equivalent), e.g., for cancer or an autoimmune disease, or planned receipt throughout the study. inhaled/nebulized, intra-articular, epidural, or topical (skin or eyes) corticosteroids are permitted. any other licensed vaccines given within 28 days prior to the investigational vaccination, or planned administration of vaccine(s) within 28 days after (full) vaccination. receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies, form 60 days before vaccine administration, or receipt of any passive antibody therapy specific to covid-19, from 90 days before vaccine administration, or planned receipt throughout the study. blood donation or blood loss ≥450ml within 1 month prior to enrollment or planned to donate blood during the study period. participation in other studies involving study intervention within 28 days prior to study entry, and/or during the study. women who are pregnant or breastfeeding. participants deemed unsuitable for participation in this study based on the investigator's assessment. (for group 1 only: criteria for delay of 2nd dose of vaccination) fever within 24 hours prior to the 2nd dose of vaccination (axillary body temperature ≥37.3℃/99.1°f). (for group 1 only: criteria for delay of 2nd dose of vaccination) during treatment/recovery from illness. (for group 1 only: criteria for delay of 2nd dose of vaccination) other conditions considered by the investigator to be unsuitable for vaccination. (for group 1 only: criteria for termination of 2nd dose of vaccination) participants with a positive urine pregnancy or blood pregnancy test (women of childbearing age only). (for group 1 only: criteria for termination of 2nd dose of vaccination) serious allergic reactions or serious adverse events related to vaccination (as assessed by the investigator) following a previous dose of vaccine. (for group 1 only: criteria for termination of 2nd dose of vaccination) positive result for sars-cov-2 (positive rt-pcr test). (for group 1 only: criteria for termination of 2nd dose of vaccination) the investigator considers inappropriate for the participants to continue participation in the study.

any screening hematology and/or blood biochemistry laboratory value that meets the definition of a ≥grade 1 abnormality, (for group 1 only) confirmed sars-cov-2 diagnosis within 1 years before screening visit. history of severe acute respiratory syndrome (sars), middle east respiratory syndrome (mers), or other coronavirus infections. receipt of medications intended to treat covid-19 with 1 year. history of server adverse reaction associated with a vaccine or drug and/or severe allergic reaction (e.g., anaphylaxis) to any component of the study intervention(s). sars-cov-2 rt-pcr positive nasopharyngeal/oropharyngeal swab specimens at screening. positive hiv test at screening. a history or family history of convulsions, epilepsy, encephalopathy and psychosis. malignant tumors in the active phase, malignant tumors not receiving adequate treatment, malignant tumors at potential risk of recurrence during the study period. asplenia of functional asplenia, complete or partial splenectomy from any cause. individuals who receive treatment with radiotherapy or immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids (if systemic corticosteroids are administered for≥14 days at a dose of ≥20 mg/day of prednisone or equivalent), e.g., for cancer or an autoimmune disease, or planned receipt throughout the study. inhaled/nebulized, intra-articular, epidural, or topical (skin or eyes) corticosteroids are permitted. any other licensed vaccines given within 28 days prior to the investigational vaccination, or planned administration of vaccine(s) within 28 days after (full) vaccination. receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies, form 60 days before vaccine administration, or receipt of any passive antibody therapy specific to covid-19, from 90 days before vaccine administration, or planned receipt throughout the study. blood donation or blood loss ≥450ml within 1 month prior to enrollment or planned to donate blood during the study period. participation in other studies involving study intervention within 28 days prior to study entry, and/or during the study. women who are pregnant or breastfeeding. participants deemed unsuitable for participation in this study based on the investigator's assessment. (for group 1 only: criteria for delay of 2nd dose of vaccination) fever within 24 hours prior to the 2nd dose of vaccination (axillary body temperature ≥37.3℃/99.1°f). (for group 1 only: criteria for delay of 2nd dose of vaccination) during treatment/recovery from illness. (for group 1 only: criteria for delay of 2nd dose of vaccination) other conditions considered by the investigator to be unsuitable for vaccination. (for group 1 only: criteria for termination of 2nd dose of vaccination) participants with a positive urine pregnancy or blood pregnancy test (women of childbearing age only). (for group 1 only: criteria for termination of 2nd dose of vaccination) serious allergic reactions or serious adverse events related to vaccination (as assessed by the investigator) following a previous dose of vaccine. (for group 1 only: criteria for termination of 2nd dose of vaccination) positive result for sars-cov-2 (positive rt-pcr test). (for group 1 only: criteria for termination of 2nd dose of vaccination) the investigator considers inappropriate for the participants to continue participation in the study.