Inclusion Criteria:

1. Healthy males and females, adolescents age 12-17 years old. Healthy status will be
determined by the investigator based on medical history, clinical laboratory
results, vital sign measurements, and physical examination at screening.

2. Subjects already received 2 (two) doses of Coronavac (Sinovac) vaccines at least 3
months prior to this study.

3. Subjects and the parents or guardian have been informed properly regarding the study
and signed the informed consent form

4. Subject and the parents or guardian will commit to comply with the instructions of
the investigator and the schedule of the trial

5. Participants agree not to donate bone marrow, blood, and blood products from the
first study vaccine administration until 3 months after receiving the vaccine.

6. Participants and the parents or guardian must be willing to provide verifiable
identification, has means to be contacted and to contact the investigator during the
study.

Exclusion Criteria:

1. Subjects concomitantly enrolled or scheduled to be enrolled in another vaccine trial

2. Evolving mild, moderate, and severe illness, especially infectious diseases or fever
(axillary temperature 37.5oC or more) concurrent or within 7 days prior to study
vaccination. This includes respiratory or constitutional symptms consistent with
SARS-CoV-2 (cough, sore throat, difficulty in breathing, etc)

3. Known history of allergy to any component of the vaccines

4. History of uncontrolled coagulopathy or blood disorders contraindicating
intramuscular injection

5. Any autoimmune or immunodeficiency disease/condition

6. Subjects who have received in the previous 4 weeks a treatment likely to alter the
immune response (intravenous immunoglobulin, blood derived products, long term
corticosteroid - more than 2 weeks, and so on), OR anticipation of the need for
immunosuppressive treatment within 6 months after last vaccination. The use of
topical or nasal steroid will be permitted. Inhaled glucocorticoids are prohibited.

7. Unstable chronic disease, inclusive of uncontrolled hypertension, congestive heart
failure, chronic obstructive pulmonary disease, asthma, chronic urticaria, diabetes
requiring use of medicine. The final decision regarding this condition will be
decided by the attending field clinicians or investigator.

8. Any abnormality or chronic disease which according to the investigator might
interfere with the assessment of the trial objectives

9. Subjects already immunized with any other vaccines within 4 weeks prior and expect
to receive other vaccines within 60 days following the first dose

10. Individuals who have a previously ascertained Covid-19 in the period of 1 month (for
mild, moderate, or asymptomatic people) or 3 months (for severe Covid-19) before the
first recruit of this study, or in a close contact in the last 14 days with
confirmed case of Covid-19.

11. Positive test for SARS-CoV-2 (Antigen or PCR) at screening prior to the vaccination.
Testing may be repeated during the screening period if exposure to positive
confirmed case of SARS-CoV-2 is suspected, at the discretion of investigator.

12. History of alcohol or substance abuse

13. HIV patients.

14. Malignancy patients within 3 years prior to study vaccination.

15. Any neurological disease or history of significant neurological disorder such as
meningitis, encephalitis, Guillain-Barre Syndrome, multiple sclerosis, etc

16. Vital sign abnormalities and clinical laboratory abnormalities as decided by the
investigators. Vital sign measurements and clinical laboratory testing may be
repeated before the final decision.

17. Women who are pregnant or who plan to become pregnant during the study.

18. Participant has major psychiatric problem or illness

19. Participant cannot communicate reliably with the investigator

20. Participant has contraindication to intramuscular injection and blood draws, such as
bleeding disorders or phobia.

21. Participant had major surgery within 12 weeks before vaccination which will not be
fully recovered, or has major surgery planned during the time participant is
expected to participate in the study or within 6 months after the vaccination.

22. Any condition that in the opinion of the investigators would pose a health risk to
the subject if enrolled or could interfere with the evaluation of the vaccine or
interpretation of the study results

23. Study team members.

24. Subject planning to move from the study area before the end of study period.