Inclusion Criteria:

1. Adult males or females aged 18 years and above at the time of consent.

2. Participants who provide a voluntarily consent to participate in the study and sign
the consent form.

3. Participants who have previously received homologous 2-dose of SARS-COV-2 Vaccine
(either Vero Cell inactivated-Sinopharm SARS-COV-2 Vaccine, CoronaVac SARS-COV-2
Vaccine, or Cominarty/Pfizer mRNA COVID-19 Vaccine) authorized for emergency use,
between 6 to 12 months post second prime vaccine dose prior to Day 1.

4. Participants who have negative results for swab SARS-COV-2 rapid antigen test.

Exclusion Criteria:

1. Participants who are unable to follow clinical and follow-up procedures.

2. Participants with acute fever with temperature above 38℃, coughing, breathing
difficulty, chills, muscle ache, headache, sore throat, loss of smell, or loss of
taste within 72 hours prior to the dosing.

3. Participants with a history of PCR-confirmed SARS-CoV-2 infection in the last 90
days prior to dosing.

4. Female who are pregnant or breastfeeding.

5. Participants with a history of hypersensitivity or allergic reactions including
anaphylaxis.

6. Participants with immune dysfunction, including immunodeficiency disorder, or family
history of such conditions, except HIV-positive participants in
stable/well-controlled condition.

7. Participants who received chronic administration (defined as more than 14 continuous
days) of immunosuppressant medication such as immunomodulator, immune-modifying
drug, immunoglobulin, immunotherapy, chemotherapy, systemic corticosteroid, etc.
except topical steroids or short-term oral steroids (course lasting ≤ 14 days), or
blood-derived products in the last 90 days prior to dosing.

8. Participants with a current clinically significant chronic and unstable
cardiovascular, endocrine, gastrointestinal, hepatic (including hepatitis B and C),
renal, neurological, respiratory, psychiatric or other medical disorders not
excluded by other exclusion criteria , that are assessed by the investigator as
being clinically unstable within the prior 90 days as evidenced by:

1. Hospitalization for the condition, including day surgical interventions

2. New significant organ function deterioration

3. Needing addition of new treatments or major dose adjustments of current
treatments (mild or moderate well-controlled comorbidities are allowed)

9. Participants with hemophilia or people using anticoagulants who are at a risk of
serious bleeding from IM injection.

10. Participants with a current dependent on antipsychotic drugs and narcotic
analgesics, or suspected of alcohol or drug dependency.

11. Participants who have received or plans to receive other vaccination(s) within 28
days prior to or during study duration (except for influenza vaccine which is not
allowed within 14 days before, or 4 weeks after final dose of IP).

12. Participants who have received or have plans to receive other investigational
drug(s) while participating in another clinical study or bioequivalence study within
28 days prior to vaccination. -