1. Male or female participants between the ages of 18 and 85 years, inclusive, at randomization, 2. Participants who are willing and able to comply with all scheduled visits, vaccination plan, laboratory tests, lifestyle considerations, and other study procedures, 3. Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study, Note: Healthy participants with preexisting stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included, 4. Capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form and this protocol, 5. SARS-CoV-2 antibody test screening is negative, 6. Negative SARS-CoV-2 test in throat swabs by RT-PCR (only for the first approximately 150 subjects), 7. Normal in chest CT scans (no imaging features of COVID-19, only for the first approximately 150 subjects).

1. Male or female participants between the ages of 18 and 85 years, inclusive, at randomization, 2. Participants who are willing and able to comply with all scheduled visits, vaccination plan, laboratory tests, lifestyle considerations, and other study procedures, 3. Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study, Note: Healthy participants with preexisting stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included, 4. Capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form and this protocol, 5. SARS-CoV-2 antibody test screening is negative, 6. Negative SARS-CoV-2 test in throat swabs by RT-PCR (only for the first approximately 150 subjects), 7. Normal in chest CT scans (no imaging features of COVID-19, only for the first approximately 150 subjects).