inclusion criteria: * male or female participants between the ages of 18 and 85 years, inclusive, at randomization. * participants who are willing and able to comply with all scheduled visits, vaccination plan, laboratory tests, lifestyle considerations, and other study procedures. * 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. * capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form and this protocol. * sars-cov-2 antibody test screening is negative. * negative sars-cov-2 test in throat swabs by reverse transcription-polymerase chain reaction (rt-pcr) (only for the first approximately 150 subjects). * normal in chest computed tomography (ct) scans (no imaging features of coronavirus disease 2019 (covid-19), only for the first approximately 150 subjects).

inclusion criteria: * male or female participants between the ages of 18 and 85 years, inclusive, at randomization. * participants who are willing and able to comply with all scheduled visits, vaccination plan, laboratory tests, lifestyle considerations, and other study procedures. * 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. * capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form and this protocol. * sars-cov-2 antibody test screening is negative. * negative sars-cov-2 test in throat swabs by reverse transcription-polymerase chain reaction (rt-pcr) (only for the first approximately 150 subjects). * normal in chest computed tomography (ct) scans (no imaging features of coronavirus disease 2019 (covid-19), only for the first approximately 150 subjects).

inclusion criteria: - male or female participants between the ages of 18 and 85 years, inclusive, at randomization. - participants who are willing and able to comply with all scheduled visits, vaccination plan, laboratory tests, lifestyle considerations, and other study procedures. - 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. - capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form and this protocol. - sars-cov-2 antibody test screening is negative. - negative sars-cov-2 test in throat swabs by reverse transcription-polymerase chain reaction (rt-pcr) (only for the first approximately 150 subjects). - normal in chest computed tomography (ct) scans (no imaging features of coronavirus disease 2019 (covid-19), only for the first approximately 150 subjects).

inclusion criteria: - male or female participants between the ages of 18 and 85 years, inclusive, at randomization. - participants who are willing and able to comply with all scheduled visits, vaccination plan, laboratory tests, lifestyle considerations, and other study procedures. - 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. - capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form and this protocol. - sars-cov-2 antibody test screening is negative. - negative sars-cov-2 test in throat swabs by reverse transcription-polymerase chain reaction (rt-pcr) (only for the first approximately 150 subjects). - normal in chest computed tomography (ct) scans (no imaging features of coronavirus disease 2019 (covid-19), only for the first approximately 150 subjects).