inclusion criteria: * males or females, ages 18 to 85 (inclusive) at the time of screening. * negative pcr and no presence of elisa antibody titers to sars-cov-2 at screening. * no clinically significant abnormalities in hematology, blood chemistry, or urinalysis laboratory tests at screening. * must agree not to enroll in another study of an investigational agent prior to completion of the study. * normal oral temperature, pulse rate no greater than 100 beats per minute (sinus rhythm) and controlled blood pressure (in the case of hypertensives under treatment, below 140/90 mmhg). * subjects must be able to understand the requirements of the study and must be accessible and willing to comply with the study procedures even under lock down conditions. * ability to provide informed consent -

inclusion criteria: * males or females, ages 18 to 85 (inclusive) at the time of screening. * negative pcr and no presence of elisa antibody titers to sars-cov-2 at screening. * no clinically significant abnormalities in hematology, blood chemistry, or urinalysis laboratory tests at screening. * must agree not to enroll in another study of an investigational agent prior to completion of the study. * normal oral temperature, pulse rate no greater than 100 beats per minute (sinus rhythm) and controlled blood pressure (in the case of hypertensives under treatment, below 140/90 mmhg). * subjects must be able to understand the requirements of the study and must be accessible and willing to comply with the study procedures even under lock down conditions. * ability to provide informed consent -

inclusion criteria: - males or females, ages 18 to 85 (inclusive) at the time of screening. - negative pcr and no presence of elisa antibody titers to sars-cov-2 at screening. - no clinically significant abnormalities in hematology, blood chemistry, or urinalysis laboratory tests at screening. - must agree not to enroll in another study of an investigational agent prior to completion of the study. - normal oral temperature, pulse rate no greater than 100 beats per minute (sinus rhythm) and controlled blood pressure (in the case of hypertensives under treatment, below 140/90 mmhg). - subjects must be able to understand the requirements of the study and must be accessible and willing to comply with the study procedures even under lock down conditions. - ability to provide informed consent -

inclusion criteria: - males or females, ages 18 to 85 (inclusive) at the time of screening. - negative pcr and no presence of elisa antibody titers to sars-cov-2 at screening. - no clinically significant abnormalities in hematology, blood chemistry, or urinalysis laboratory tests at screening. - must agree not to enroll in another study of an investigational agent prior to completion of the study. - normal oral temperature, pulse rate no greater than 100 beats per minute (sinus rhythm) and controlled blood pressure (in the case of hypertensives under treatment, below 140/90 mmhg). - subjects must be able to understand the requirements of the study and must be accessible and willing to comply with the study procedures even under lock down conditions. - ability to provide informed consent -