inclusion criteria: * age ≥18 years * laboratory-confirmed sars-cov-2 infection within 3 days (of proposed consent) or the presence of symptoms or signs providing a high probability of covid-19 disease who have symptoms within 7 days prior to diagnosis as determined by infectious disease specialist or treating physicians. * outpatients. no previous hospitalization within the past 3 months. * subjects must have at least one of the following high-risk features for clinical deterioration: * hypertension * diabetes mellitus * moderate to severe chronic obstructive pulmonary disease or asthma * cancer patients who have received any immunosuppressive drugs within a year from enrollment. * obesity as defined by a body mass index \> 30 kg/m2. * living in a nursing home or long-term facility * underlying serious heart condition as determined by the treating physician * immunocompromised subject as defined by the treating physician or by the infectious disease specialist * ability to provide informed consent by the patient or healthcare proxy. * ability to return for repeated testing and observation to the hospital. * patients must have adequate organ and marrow function measured within the last 30 days as defined below: * platelets ≥100,000 * aspartate transaminase or alanine transaminase ≤3 times institutional upper limit of normal * creatinine ≤ 1.5 times institutional upper limit of normal or * glomerular filtration rate ≥45 ml/min/1.73 m2 unless data exists supporting safe use at lower kidney function values, no lower than 30 ml/min/1.73 m2

inclusion criteria: * age ≥18 years * laboratory-confirmed sars-cov-2 infection within 3 days (of proposed consent) or the presence of symptoms or signs providing a high probability of covid-19 disease who have symptoms within 7 days prior to diagnosis as determined by infectious disease specialist or treating physicians. * outpatients. no previous hospitalization within the past 3 months. * subjects must have at least one of the following high-risk features for clinical deterioration: * hypertension * diabetes mellitus * moderate to severe chronic obstructive pulmonary disease or asthma * cancer patients who have received any immunosuppressive drugs within a year from enrollment. * obesity as defined by a body mass index \> 30 kg/m2. * living in a nursing home or long-term facility * underlying serious heart condition as determined by the treating physician * immunocompromised subject as defined by the treating physician or by the infectious disease specialist * ability to provide informed consent by the patient or healthcare proxy. * ability to return for repeated testing and observation to the hospital. * patients must have adequate organ and marrow function measured within the last 30 days as defined below: * platelets ≥100,000 * aspartate transaminase or alanine transaminase ≤3 times institutional upper limit of normal * creatinine ≤ 1.5 times institutional upper limit of normal or * glomerular filtration rate ≥45 ml/min/1.73 m2 unless data exists supporting safe use at lower kidney function values, no lower than 30 ml/min/1.73 m2

inclusion criteria: - age ≥18 years - laboratory-confirmed sars-cov-2 infection within 3 days (of proposed consent) or the presence of symptoms or signs providing a high probability of covid-19 disease who have symptoms within 7 days prior to diagnosis as determined by infectious disease specialist or treating physicians. - outpatients. no previous hospitalization within the past 3 months. - subjects must have at least one of the following high-risk features for clinical deterioration: - hypertension - diabetes mellitus - moderate to severe chronic obstructive pulmonary disease or asthma - cancer patients who have received any immunosuppressive drugs within a year from enrollment. - obesity as defined by a body mass index > 30 kg/m2. - living in a nursing home or long-term facility - underlying serious heart condition as determined by the treating physician - immunocompromised subject as defined by the treating physician or by the infectious disease specialist - ability to provide informed consent by the patient or healthcare proxy. - ability to return for repeated testing and observation to the hospital. - patients must have adequate organ and marrow function measured within the last 30 days as defined below: - platelets ≥100,000 - aspartate transaminase or alanine transaminase ≤3 times institutional upper limit of normal - creatinine ≤ 1.5 times institutional upper limit of normal or - glomerular filtration rate ≥45 ml/min/1.73 m2 unless data exists supporting safe use at lower kidney function values, no lower than 30 ml/min/1.73 m2

inclusion criteria: - age ≥18 years - laboratory-confirmed sars-cov-2 infection within 3 days (of proposed consent) or the presence of symptoms or signs providing a high probability of covid-19 disease who have symptoms within 7 days prior to diagnosis as determined by infectious disease specialist or treating physicians. - outpatients. no previous hospitalization within the past 3 months. - subjects must have at least one of the following high-risk features for clinical deterioration: - hypertension - diabetes mellitus - moderate to severe chronic obstructive pulmonary disease or asthma - cancer patients who have received any immunosuppressive drugs within a year from enrollment. - obesity as defined by a body mass index > 30 kg/m2. - living in a nursing home or long-term facility - underlying serious heart condition as determined by the treating physician - immunocompromised subject as defined by the treating physician or by the infectious disease specialist - ability to provide informed consent by the patient or healthcare proxy. - ability to return for repeated testing and observation to the hospital. - patients must have adequate organ and marrow function measured within the last 30 days as defined below: - platelets ≥100,000 - aspartate transaminase or alanine transaminase ≤3 times institutional upper limit of normal - creatinine ≤ 1.5 times institutional upper limit of normal or - glomerular filtration rate ≥45 ml/min/1.73 m2 unless data exists supporting safe use at lower kidney function values, no lower than 30 ml/min/1.73 m2