Inclusion Criteria:

1. Male or non-pregnant female, aged 18 to 55 years old (inclusive) at the Screening
visit.

2. Body mass index (BMI) of 18.0 to 32.0 kg/m2 (inclusive) at the Screening visit.

3. Physically and mentally capable of participating in the study and willing to adhere
to study procedures.

4. Able to provide signed informed consent.

5. In generally good health with no clinically significant abnormal findings in medical
history, physical examination, vital signs, ECG, and clinical laboratory findings at
the Screening visit based on the Investigator's judgment.

6. Negative serology test for human immunodeficiency virus (HIV) antigen and antibody,
hepatitis B surface antigen, and hepatitis C antibody at the Screening visit.

7. All female subjects must have a negative result of pregnancy test at the Screening
visit.

8. Female subject with childbearing potential must be willing to implement adequate,
highly effective contraceptive measures from the Screening Visit (unless otherwise
stated) through end of study (EOS). Effective birth control includes:

1. Progesterone implant (in place for at least 3 months prior to the Screening
Visit) with condom

2. Progesterone only hormonal contraception (oral or injectable; used
consecutively for at least 3 months prior to the Screening Visit) with condom

3. Progesterone releasing intrauterine device (IUD; in place for at least 3 months
prior to the Screening Visit) with condom

4. Non-hormonal IUD (in place for at least 3 months prior to the Screening Visit)

5. Bilateral occlusion/tubal ligation

6. Azoospermic partner

7. Combined contraceptives (oral, intravaginal, transdermal, implantable, or
injectable; in place for at least 3 months prior to the Screening Visit) plus
condom; or

8. Sexual abstinence as the preferred lifestyle (refraining from heterosexual
activity) Women of childbearing potential are those who have not been
surgically sterilized (hysterectomy, bilateral salpingectomy and bilateral
oophorectomy) or are not postmenopausal, defined as no menses for ≥ 12 months
without alternative cause with confirmatory laboratory levels.

9. Male subject who agrees to use an adequate method of contraception during the study
period (e.g. barrier contraceptives [male condom]).

Exclusion Criteria:

1. Any medical or psychiatric condition that, in the opinion of the Investigator, may
interfere with optimal participation in the study or place the subject at increased
risk of Adverse Events (AEs).

2. Suspected or known hypersensitivity (including allergy) to any of the ingredients or
components in the study vaccine.

3. History of hypersensitivity or allergy to any vaccine.

4. Current, confirmed or suspected acute COVID-19 with positive test for SARS-CoV-2
virus at the Screening visit or at check-in for each period. Acute infection will be
confirmed/excluded via symptoms and COVID-19 PCR or antigen testing, including
positive COVID-19 PCR or rapid antigen test result within 3 months prior to
Screening, reported verbally.

5. Prior history of heart diseases of concern: history of myocarditis, pericarditis,
cardiomyopathy, coronary artery disease (including history of myocardial infarction,
unstable angina), Class III and above heart failure, or significant arrhythmias.

6. Medical conditions as a contraindication to the IM vaccination and blood draws, e.g.
coagulation disorder.

7. Any abnormality or permanent body art (e.g. tattoo) that would interfere with the
observation of local reactions at the injection site (deltoid region).

8. Acute or chronic, clinically significant cardiovascular, pulmonary, hepatic or renal
diseases and/or insufficiency as determined by physical examination or laboratory
tests.

9. Known or suspected impairment of immunological function, e.g. asplenia/splenectomy
or history of autoimmune/immune-mediated diseases or lymphoproliferative disorders.

10. History of any chronic or progressive disease that, according to judgment of the
Investigator, could interfere with the study outcomes or pose a threat to the
subject's health.

11. History of cancer (except localized skin cancer without metastases) within 5 years
prior to the Screening visit.

12. History or presence of heavy smoking (defined as > 10 cigarettes per day;
approximately half pack per day) as documented in medical chart or by verbal
confirmation at the Screening visit.

13. Documented history of substance or alcohol abuse in the medical chart or by verbal
confirmation within 6 months prior to the Screening visit.

14. Corrected QT using Fredericia's formula (QTcF) prolongation > 450 milliseconds in
males and >470 milliseconds in females at Screening visit.

15. Abnormal troponin (cardiac troponin; cTN) value at Screening visit.

16. Received any investigational or licensed COVID-19 vaccines within 6 months prior to
the Screening visit.

17. Received marketed inactivated vaccines against seasonal influenza within 7 days
prior to the study vaccination, any other inactivated vaccination within 14 days
prior to the study vaccination, or live or bacterial vaccination within 28 days
prior to the study vaccination or plans to receive vaccination during the study
period or within the 14 days following study vaccination.

18. Received major surgery or radiation therapy within 3 months prior to the Screening
visit.

19. Onset of influenza-like illness as defined by: fever (temperature ≥ 38℃), dry cough,
headache, fatigue, respiratory sputum production, dysgeusia, anosmia, shortness of
breath, muscle and joint pain, or sore throat within 1 week prior to the Screening
visit and within 48-hours of each vaccination. Subject can be re-evaluated after
resolution of symptoms within the screening window.

20. Female subject who is pregnant at the Screening visit or planning to be pregnant
during the study period.

21. Female subject who is breastfeeding at the Screening visit or plans to breastfeed
from the time of the first vaccination through 60 days after the last vaccination.

22. Received any investigational mRNA COVID-19 vaccination within 6 months prior to the
Screening visit or have received any other investigational drug or device or have
participated in a clinical study within 28 days or 5 half-lives of investigational
drug prior to the Screening visit.

23. Any confirmed or suspected abnormal immune function, immunosuppression, or
immunodeficiency or received any immunosuppressants (including systemic
corticosteroids) or immunomodulators within 3 months prior to the Screening visit.

24. Had donated blood within 2 weeks prior to the Screening visit.

25. Received any blood products or immunoglobulin within 3 months prior to the Screening
visit.