inclusion criteria: 1. participant must be aged 19 years and older at the time of signing the informed consent. 2. participants who are healthy or medically stabilized according to medical judgment of the investigator based on medical history, physical examination and clinical laboratory tests, etc. 3. participants who are able to attend all scheduled visits and comply with all study procedures. 4. (cohort 1\~5) participants who received a primary series of covid-19 vaccination approved for use in korea by mfds and at least 12\~24 weeks have passed with no additional covid-19 vaccination. 5. (cohort 6\~7) participants who received a primary series of covid-19 vaccination and the 1st booster vaccination at least 16 weeks ago through a homologous or heterologous vaccination with mrna vaccines (bnt162b2 (pfizer) and mrna-1273 (moderna)) only or at least more than a single dose of non-mrna vaccines (chadox1 ncov-19 (az), ad26.cov2.s (janssen), and nvx-cov2373 (novavax)). 6. female participants of childbearing potential must agree to be heterosexually inactive, or agree to use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination (booster vaccination) to 12 weeks after the study vaccination. 7. female participants with a negative urine or serum pregnancy test at screening (however, female participants who are surgically sterile or postmenopausal with amenorrhea for at least 12 months shall be excluded. 8. participants who give signed informed consent which include compliance with the requirements and restrictions listed in the informed consent form and in the protocol.

inclusion criteria: 1. participant must be aged 19 years and older at the time of signing the informed consent. 2. participants who are healthy or medically stabilized according to medical judgment of the investigator based on medical history, physical examination and clinical laboratory tests, etc. 3. participants who are able to attend all scheduled visits and comply with all study procedures. 4. (cohort 1\~5) participants who received a primary series of covid-19 vaccination approved for use in korea by mfds and at least 12\~24 weeks have passed with no additional covid-19 vaccination. 5. (cohort 6\~7) participants who received a primary series of covid-19 vaccination and the 1st booster vaccination at least 16 weeks ago through a homologous or heterologous vaccination with mrna vaccines (bnt162b2 (pfizer) and mrna-1273 (moderna)) only or at least more than a single dose of non-mrna vaccines (chadox1 ncov-19 (az), ad26.cov2.s (janssen), and nvx-cov2373 (novavax)). 6. female participants of childbearing potential must agree to be heterosexually inactive, or agree to use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination (booster vaccination) to 12 weeks after the study vaccination. 7. female participants with a negative urine or serum pregnancy test at screening (however, female participants who are surgically sterile or postmenopausal with amenorrhea for at least 12 months shall be excluded. 8. participants who give signed informed consent which include compliance with the requirements and restrictions listed in the informed consent form and in the protocol.

inclusion criteria: participant must be aged 19 years and older at the time of signing the informed consent. participants who are healthy or medically stabilized according to medical judgment of the investigator based on medical history, physical examination and clinical laboratory tests, etc. participants who are able to attend all scheduled visits and comply with all study procedures. (cohort 1~5) participants who received a primary series of covid-19 vaccination approved for use in korea by mfds and at least 12~24 weeks have passed with no additional covid-19 vaccination. (cohort 6~7) participants who received a primary series of covid-19 vaccination and the 1st booster vaccination at least 16 weeks ago through a homologous or heterologous vaccination with mrna vaccines (bnt162b2 (pfizer) and mrna-1273 (moderna)) only or at least more than a single dose of non-mrna vaccines (chadox1 ncov-19 (az), ad26.cov2.s (janssen), and nvx-cov2373 (novavax)). female participants of childbearing potential must agree to be heterosexually inactive, or agree to use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination (booster vaccination) to 12 weeks after the study vaccination. female participants with a negative urine or serum pregnancy test at screening (however, female participants who are surgically sterile or postmenopausal with amenorrhea for at least 12 months shall be excluded. participants who give signed informed consent which include compliance with the requirements and restrictions listed in the informed consent form and in the protocol.

inclusion criteria: participant must be aged 19 years and older at the time of signing the informed consent. participants who are healthy or medically stabilized according to medical judgment of the investigator based on medical history, physical examination and clinical laboratory tests, etc. participants who are able to attend all scheduled visits and comply with all study procedures. (cohort 1~5) participants who received a primary series of covid-19 vaccination approved for use in korea by mfds and at least 12~24 weeks have passed with no additional covid-19 vaccination. (cohort 6~7) participants who received a primary series of covid-19 vaccination and the 1st booster vaccination at least 16 weeks ago through a homologous or heterologous vaccination with mrna vaccines (bnt162b2 (pfizer) and mrna-1273 (moderna)) only or at least more than a single dose of non-mrna vaccines (chadox1 ncov-19 (az), ad26.cov2.s (janssen), and nvx-cov2373 (novavax)). female participants of childbearing potential must agree to be heterosexually inactive, or agree to use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination (booster vaccination) to 12 weeks after the study vaccination. female participants with a negative urine or serum pregnancy test at screening (however, female participants who are surgically sterile or postmenopausal with amenorrhea for at least 12 months shall be excluded. participants who give signed informed consent which include compliance with the requirements and restrictions listed in the informed consent form and in the protocol.

inclusion criteria: participant must be 19 to 49 years of age inclusive, at the time of signing the informed consent. participants who are healthy or medically stabilized according to medical judgment of the investigator based on medical history, physical examination and clinical laboratory tests, etc. participants who are able to attend all scheduled visits and comply with all study procedures. participants who received a primary series of covid-19 vaccination approved for use in korea by mfds and at least 12~24 weeks have passed with no additional covid-19 vaccination. female participants of childbearing potential must agree to be heterosexually inactive, or agree to use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination (booster vaccination) to 12 weeks after the study vaccination. female participants with a negative urine or serum pregnancy test at screening (however, female participants who are surgically sterile or postmenopausal with amenorrhea for at least 12 months shall be excluded. participants who give signed informed consent which include compliance with the requirements and restrictions listed in the informed consent form and in the protocol.

inclusion criteria: participant must be 19 to 49 years of age inclusive, at the time of signing the informed consent. participants who are healthy or medically stabilized according to medical judgment of the investigator based on medical history, physical examination and clinical laboratory tests, etc. participants who are able to attend all scheduled visits and comply with all study procedures. participants who received a primary series of covid-19 vaccination approved for use in korea by mfds and at least 12~24 weeks have passed with no additional covid-19 vaccination. female participants of childbearing potential must agree to be heterosexually inactive, or agree to use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination (booster vaccination) to 12 weeks after the study vaccination. female participants with a negative urine or serum pregnancy test at screening (however, female participants who are surgically sterile or postmenopausal with amenorrhea for at least 12 months shall be excluded. participants who give signed informed consent which include compliance with the requirements and restrictions listed in the informed consent form and in the protocol.