- suspected active bacterial, fungal, viral, or other cause of respiratory failure other than covid-19 - subject is already intubated and on ventilator support - known or suspected immunosuppression with immunosuppressant medications or chemotherapeutic agents - subject is on dialysis - on home ventilator support or continuous domiciliary o2 therapy for baseline lung disease - active tuberculosis (tb) infection

- suspected active bacterial, fungal, viral, or other cause of respiratory failure other than covid-19 - subject is already intubated and on ventilator support - known or suspected immunosuppression with immunosuppressant medications or chemotherapeutic agents - subject is on dialysis - on home ventilator support or continuous domiciliary o2 therapy for baseline lung disease - active tuberculosis (tb) infection