inclusion criteria: * the age when signing icf should meet the requirements of the scheme (group a ≥18 years old; group b 12-17 years old; group c, 3-11 years old) male or female; * have previously received the recommended dose and immunization procedures of covid-19 vaccine approved for domestic market, and the interval between signing icf and receiving the last dose of covid-19 vaccine is 6-24 months; * subject and/or guardian or client of both parties are able to sign a written icf and voluntarily participate in the trial, fully understand the trial procedure, the risks of participating in the trial and the alternative interventions available to non-participants; * the subject and/or the guardian or client of both parties can read, understand and fill in the diary card; * healthy subjects or subjects with stable underlying diseases. stable underlying diseases were defined as those who were in stable condition at least 3 months before inclusion in the study, had no significant change in treatment regimen and had not been admitted to hospital due to disease progression; * fertile men and women of childbearing age voluntarily agree to take effective contraceptive measures from signing the icf to 180 days after receiving the trial vaccine; pregnancy tests for women of childbearing age during the screening period were negative.

inclusion criteria: * the age when signing icf should meet the requirements of the scheme (group a ≥18 years old; group b 12-17 years old; group c, 3-11 years old) male or female; * have previously received the recommended dose and immunization procedures of covid-19 vaccine approved for domestic market, and the interval between signing icf and receiving the last dose of covid-19 vaccine is 6-24 months; * subject and/or guardian or client of both parties are able to sign a written icf and voluntarily participate in the trial, fully understand the trial procedure, the risks of participating in the trial and the alternative interventions available to non-participants; * the subject and/or the guardian or client of both parties can read, understand and fill in the diary card; * healthy subjects or subjects with stable underlying diseases. stable underlying diseases were defined as those who were in stable condition at least 3 months before inclusion in the study, had no significant change in treatment regimen and had not been admitted to hospital due to disease progression; * fertile men and women of childbearing age voluntarily agree to take effective contraceptive measures from signing the icf to 180 days after receiving the trial vaccine; pregnancy tests for women of childbearing age during the screening period were negative.

inclusion criteria: the age when signing icf should meet the requirements of the scheme (group a ≥18 years old; group b 12-17 years old; group c, 3-11 years old) male or female; have previously received the recommended dose and immunization procedures of covid-19 vaccine approved for domestic market, and the interval between signing icf and receiving the last dose of covid-19 vaccine is 6-24 months; subject and/or guardian or client of both parties are able to sign a written icf and voluntarily participate in the trial, fully understand the trial procedure, the risks of participating in the trial and the alternative interventions available to non-participants; the subject and/or the guardian or client of both parties can read, understand and fill in the diary card; healthy subjects or subjects with stable underlying diseases. stable underlying diseases were defined as those who were in stable condition at least 3 months before inclusion in the study, had no significant change in treatment regimen and had not been admitted to hospital due to disease progression; fertile men and women of childbearing age voluntarily agree to take effective contraceptive measures from signing the icf to 180 days after receiving the trial vaccine; pregnancy tests for women of childbearing age during the screening period were negative.

inclusion criteria: the age when signing icf should meet the requirements of the scheme (group a ≥18 years old; group b 12-17 years old; group c, 3-11 years old) male or female; have previously received the recommended dose and immunization procedures of covid-19 vaccine approved for domestic market, and the interval between signing icf and receiving the last dose of covid-19 vaccine is 6-24 months; subject and/or guardian or client of both parties are able to sign a written icf and voluntarily participate in the trial, fully understand the trial procedure, the risks of participating in the trial and the alternative interventions available to non-participants; the subject and/or the guardian or client of both parties can read, understand and fill in the diary card; healthy subjects or subjects with stable underlying diseases. stable underlying diseases were defined as those who were in stable condition at least 3 months before inclusion in the study, had no significant change in treatment regimen and had not been admitted to hospital due to disease progression; fertile men and women of childbearing age voluntarily agree to take effective contraceptive measures from signing the icf to 180 days after receiving the trial vaccine; pregnancy tests for women of childbearing age during the screening period were negative.