1. Participants must age 5 to &lt,12 years old. 2. Participants must be completed 2-dose of inactivated Covid-19 vaccine (CoronavacTM/CoviloTM) 4-24 weeks prior to study enrollment. 3. Participants must be in good health at the time of entry into the trial as determined by medical history, physical examination (including vital signs), and the clinical judgment of the investigator. 4. Participants or caregivers must be able to communicate effectively with study personnel and considered reliable, willing, and cooperative in terms of compliance with the protocol requirements. 5. Participants and/or parent(s) or legally authorized representative(s) must sign a written informed consent form, including any required privacy authorization form, prior to the initiation of any trial procedures, after the nature of the trial has been explained according to local regulatory requirements.

1. Participants must age 5 to &lt,12 years old. 2. Participants must be completed 2-dose of inactivated Covid-19 vaccine (CoronavacTM/CoviloTM) 4-24 weeks prior to study enrollment. 3. Participants must be in good health at the time of entry into the trial as determined by medical history, physical examination (including vital signs), and the clinical judgment of the investigator. 4. Participants or caregivers must be able to communicate effectively with study personnel and considered reliable, willing, and cooperative in terms of compliance with the protocol requirements. 5. Participants and/or parent(s) or legally authorized representative(s) must sign a written informed consent form, including any required privacy authorization form, prior to the initiation of any trial procedures, after the nature of the trial has been explained according to local regulatory requirements.