inclusion criteria: male or female, ≥18 years of age at screening. confirmed infection with sars-cov-2. high risk of covid-19 disease progression, defined as: 18-69 years of age with lymphopenia and 1 additional risk factor (described below) 18-69 years of age without lymphopenia and 2 risk factors (described below) ≥70 years of age with lymphopenia or 1 other risk factor (described below) risk factors: documented history of coronary artery disease heart failure (new york heart association class 3 or 4) chronic lung disease (eg, asthma or chronic obstructive pulmonary disease) requiring treatment documented history of stroke diabetes mellitus, requiring at least 1 prescription medicine for management documented chronic kidney disease with an estimated glomerular filtration rate <30 ml/min, not on dialysis obesity (class 2 or 3; body mass index >34.9 kg/m2) on immunosuppressive therapy oxygen saturation between 90 and 95% with or without supplemental oxygen admitted to a hospital for observation and/or treatment (controlled facility may include an emergency room, urgent care facility, temporary/modular hospital, infusion center, clinical research unit, etc). if female, must be postmenopausal, surgically sterile, or if of childbearing potential, must be practicing 2 effective methods of birth control during the study and through 30 days after completion of the study. for females of childbearing potential, a urine pregnancy test must be negative at the screening visit. if male, must be surgically sterile or willing to practice 2 effective methods of birth control during the study and through 30 days after completion of the study. must be willing and able to give informed consent and comply with all study procedures.

inclusion criteria: male or female, ≥18 years of age at screening. confirmed infection with sars-cov-2. high risk of covid-19 disease progression, defined as: 18-69 years of age with lymphopenia and 1 additional risk factor (described below) 18-69 years of age without lymphopenia and 2 risk factors (described below) ≥70 years of age with lymphopenia or 1 other risk factor (described below) risk factors: documented history of coronary artery disease heart failure (new york heart association class 3 or 4) chronic lung disease (eg, asthma or chronic obstructive pulmonary disease) requiring treatment documented history of stroke diabetes mellitus, requiring at least 1 prescription medicine for management documented chronic kidney disease with an estimated glomerular filtration rate <30 ml/min, not on dialysis obesity (class 2 or 3; body mass index >34.9 kg/m2) on immunosuppressive therapy oxygen saturation between 90 and 95% with or without supplemental oxygen admitted to a hospital for observation and/or treatment (controlled facility may include an emergency room, urgent care facility, temporary/modular hospital, infusion center, clinical research unit, etc). if female, must be postmenopausal, surgically sterile, or if of childbearing potential, must be practicing 2 effective methods of birth control during the study and through 30 days after completion of the study. for females of childbearing potential, a urine pregnancy test must be negative at the screening visit. if male, must be surgically sterile or willing to practice 2 effective methods of birth control during the study and through 30 days after completion of the study. must be willing and able to give informed consent and comply with all study procedures.

inclusion criteria: 1. male or female, ≥18 years of age at screening. 2. confirmed infection with sars-cov-2. 3. high risk of covid-19 disease progression, defined as: 1. 18-69 years of age with lymphopenia and 1 additional risk factor (described below) 2. 18-69 years of age without lymphopenia and 2 risk factors (described below) 3. ≥70 years of age with lymphopenia or 1 other risk factor (described below) risk factors: - documented history of coronary artery disease - heart failure (new york heart association class 3 or 4) - chronic lung disease (eg, asthma or chronic obstructive pulmonary disease) requiring treatment - documented history of stroke - diabetes mellitus, requiring at least 1 prescription medicine for management - documented chronic kidney disease with an estimated glomerular filtration rate <30 ml/min, not on dialysis - obesity (class 2 or 3; body mass index >34.9 kg/m2) - on immunosuppressive therapy - oxygen saturation between 90 and 95% with or without supplemental oxygen 4. admitted to a hospital for observation and/or treatment (controlled facility may include an emergency room, urgent care facility, temporary/modular hospital, infusion center, clinical research unit, etc). 5. if female, must be postmenopausal, surgically sterile, or if of childbearing potential, must be practicing 2 effective methods of birth control during the study and through 30 days after completion of the study. 6. for females of childbearing potential, a urine pregnancy test must be negative at the screening visit. 7. if male, must be surgically sterile or willing to practice 2 effective methods of birth control during the study and through 30 days after completion of the study. 8. must be willing and able to give informed consent and comply with all study procedures.

inclusion criteria: 1. male or female, ≥18 years of age at screening. 2. confirmed infection with sars-cov-2. 3. high risk of covid-19 disease progression, defined as: 1. 18-69 years of age with lymphopenia and 1 additional risk factor (described below) 2. 18-69 years of age without lymphopenia and 2 risk factors (described below) 3. ≥70 years of age with lymphopenia or 1 other risk factor (described below) risk factors: - documented history of coronary artery disease - heart failure (new york heart association class 3 or 4) - chronic lung disease (eg, asthma or chronic obstructive pulmonary disease) requiring treatment - documented history of stroke - diabetes mellitus, requiring at least 1 prescription medicine for management - documented chronic kidney disease with an estimated glomerular filtration rate <30 ml/min, not on dialysis - obesity (class 2 or 3; body mass index >34.9 kg/m2) - on immunosuppressive therapy - oxygen saturation between 90 and 95% with or without supplemental oxygen 4. admitted to a hospital for observation and/or treatment (controlled facility may include an emergency room, urgent care facility, temporary/modular hospital, infusion center, clinical research unit, etc). 5. if female, must be postmenopausal, surgically sterile, or if of childbearing potential, must be practicing 2 effective methods of birth control during the study and through 30 days after completion of the study. 6. for females of childbearing potential, a urine pregnancy test must be negative at the screening visit. 7. if male, must be surgically sterile or willing to practice 2 effective methods of birth control during the study and through 30 days after completion of the study. 8. must be willing and able to give informed consent and comply with all study procedures.