inclusion criteria: * covid-19 diagnosis (confirmation of the presence of sars-cov-2 virus by rt-pcr) or sample collection for sars-cov-2 virus rt-pcr if the results of sars-cov-2 virus rt-pcr are not available yet. * dated informed consent for participation in this study signed by the patient, or by the legally acceptable representative or when prior consent of the patient is not possible, and the subject's legally acceptable representative is not available, documented approval / favorable opinion by the irb/iec. * spo2 ≤93% (room air) or respiratory rate greater than 30/min (room air) or oxygenation index pao2/fio2 ≤300 mmhg (or spo2/fio2 ≤315 in the case pao2/fio2 assessment is not available (supplementary oxygen) * computed tomography findings: features consistent with bilateral covid-19 viral pneumonia and no alternative explanation for these findings.

inclusion criteria: * covid-19 diagnosis (confirmation of the presence of sars-cov-2 virus by rt-pcr) or sample collection for sars-cov-2 virus rt-pcr if the results of sars-cov-2 virus rt-pcr are not available yet. * dated informed consent for participation in this study signed by the patient, or by the legally acceptable representative or when prior consent of the patient is not possible, and the subject's legally acceptable representative is not available, documented approval / favorable opinion by the irb/iec. * spo2 ≤93% (room air) or respiratory rate greater than 30/min (room air) or oxygenation index pao2/fio2 ≤300 mmhg (or spo2/fio2 ≤315 in the case pao2/fio2 assessment is not available (supplementary oxygen) * computed tomography findings: features consistent with bilateral covid-19 viral pneumonia and no alternative explanation for these findings.

inclusion criteria: - covid-19 diagnosis (confirmation of the presence of sars-cov-2 virus by rt-pcr) or sample collection for sars-cov-2 virus rt-pcr if the results of sars-cov-2 virus rt-pcr are not available yet. - dated informed consent for participation in this study signed by the patient, or by the legally acceptable representative or when prior consent of the patient is not possible, and the subject's legally acceptable representative is not available, documented approval / favorable opinion by the irb/iec. - spo2 ≤93% (room air) or respiratory rate greater than 30/min (room air) or oxygenation index pao2/fio2 ≤300 mmhg (or spo2/fio2 ≤315 in the case pao2/fio2 assessment is not available (supplementary oxygen) - computed tomography findings: features consistent with bilateral covid-19 viral pneumonia and no alternative explanation for these findings.

inclusion criteria: - covid-19 diagnosis (confirmation of the presence of sars-cov-2 virus by rt-pcr) or sample collection for sars-cov-2 virus rt-pcr if the results of sars-cov-2 virus rt-pcr are not available yet. - dated informed consent for participation in this study signed by the patient, or by the legally acceptable representative or when prior consent of the patient is not possible, and the subject's legally acceptable representative is not available, documented approval / favorable opinion by the irb/iec. - spo2 ≤93% (room air) or respiratory rate greater than 30/min (room air) or oxygenation index pao2/fio2 ≤300 mmhg (or spo2/fio2 ≤315 in the case pao2/fio2 assessment is not available (supplementary oxygen) - computed tomography findings: features consistent with bilateral covid-19 viral pneumonia and no alternative explanation for these findings.