inclusion criteria: * hospitalized with laboratory-confirmed (rt-pcr+) or highly suspected (compatible with at least bilobar lung involvement without another plausible diagnosis) covid-19 * weight ≤100 kg * within 24 hours of reaching a who severity score of 4-6 either: * at admission * while already hospitalized * informed consent obtained from subject/next of kin/legal proxy * primary admitting diagnosis of pneumonia supported by a compatible clinical presentation with a documented infiltrate consistent with pneumonia on chest radiograph or ct as assessed by the admitting emergency-department (ed), clinic, or ward physician or equivalent caregiver * recommended (not mandatory) guidance/discretionary criteria defining patients with pneumonia satisfying all 4 categories below: * at least 2 symptoms: difficulty breathing, cough, production of purulent sputum, or chest pain * at least 2 vital sign abnormalities: fever, tachycardia, or tachypnea (thresholds -- fever: oral or core temperature \>100.4 °f \[38 °c\]; heart rate \>100 beats/min; respiratory rate \>24/min) * at least one finding of other clinical signs and laboratory abnormalities: hypoxemia (o2 saturation \<90%), clinical evidence of pulmonary consolidation, or leukocytosis or leukopenia * chest imaging or ct showing new (or presumed new or worsening) pulmonary infiltrates * principal investigator to note radiologic findings in the electronic case report form (ecrf) * radiology report to be placed in the ecrf * a copy of the radiograph attached to be saved for review * a hyperinflammatory status (defined by increased ferritin ≥500 µg/l, d-dimer ≥1000 ng/ml, or c-reactive protein (crp) ≥75 mg/l) * during the course of the study starting at screening and for at least 6 months after their final study treatment: * female subjects of childbearing potential must agree to use 2 medically accepted birth control methods * male subjects with a partner who might become pregnant must agree to use reliable forms of contraception (i.e., vasectomy, abstinence), or an acceptable method of birth control must be used by the partner * all subjects must agree not to donate sperm or eggs (ovocytes)

inclusion criteria: * hospitalized with laboratory-confirmed (rt-pcr+) or highly suspected (compatible with at least bilobar lung involvement without another plausible diagnosis) covid-19 * weight ≤100 kg * within 24 hours of reaching a who severity score of 4-6 either: * at admission * while already hospitalized * informed consent obtained from subject/next of kin/legal proxy * primary admitting diagnosis of pneumonia supported by a compatible clinical presentation with a documented infiltrate consistent with pneumonia on chest radiograph or ct as assessed by the admitting emergency-department (ed), clinic, or ward physician or equivalent caregiver * recommended (not mandatory) guidance/discretionary criteria defining patients with pneumonia satisfying all 4 categories below: * at least 2 symptoms: difficulty breathing, cough, production of purulent sputum, or chest pain * at least 2 vital sign abnormalities: fever, tachycardia, or tachypnea (thresholds -- fever: oral or core temperature \>100.4 °f \[38 °c\]; heart rate \>100 beats/min; respiratory rate \>24/min) * at least one finding of other clinical signs and laboratory abnormalities: hypoxemia (o2 saturation \<90%), clinical evidence of pulmonary consolidation, or leukocytosis or leukopenia * chest imaging or ct showing new (or presumed new or worsening) pulmonary infiltrates * principal investigator to note radiologic findings in the electronic case report form (ecrf) * radiology report to be placed in the ecrf * a copy of the radiograph attached to be saved for review * a hyperinflammatory status (defined by increased ferritin ≥500 µg/l, d-dimer ≥1000 ng/ml, or c-reactive protein (crp) ≥75 mg/l) * during the course of the study starting at screening and for at least 6 months after their final study treatment: * female subjects of childbearing potential must agree to use 2 medically accepted birth control methods * male subjects with a partner who might become pregnant must agree to use reliable forms of contraception (i.e., vasectomy, abstinence), or an acceptable method of birth control must be used by the partner * all subjects must agree not to donate sperm or eggs (ovocytes)

inclusion criteria: - hospitalized with laboratory-confirmed (rt-pcr+) or highly suspected (compatible with at least bilobar lung involvement without another plausible diagnosis) covid-19 - weight ≤100 kg - within 24 hours of reaching a who severity score of 4-6 either: - at admission - while already hospitalized - informed consent obtained from subject/next of kin/legal proxy - primary admitting diagnosis of pneumonia supported by a compatible clinical presentation with a documented infiltrate consistent with pneumonia on chest radiograph or ct as assessed by the admitting emergency-department (ed), clinic, or ward physician or equivalent caregiver - recommended (not mandatory) guidance/discretionary criteria defining patients with pneumonia satisfying all 4 categories below: - at least 2 symptoms: difficulty breathing, cough, production of purulent sputum, or chest pain - at least 2 vital sign abnormalities: fever, tachycardia, or tachypnea (thresholds -- fever: oral or core temperature >100.4 °f [38 °c]; heart rate >100 beats/min; respiratory rate >24/min) - at least one finding of other clinical signs and laboratory abnormalities: hypoxemia (o2 saturation <90%), clinical evidence of pulmonary consolidation, or leukocytosis or leukopenia - chest imaging or ct showing new (or presumed new or worsening) pulmonary infiltrates - principal investigator to note radiologic findings in the electronic case report form (ecrf) - radiology report to be placed in the ecrf - a copy of the radiograph attached to be saved for review - a hyperinflammatory status (defined by increased ferritin ≥500 µg/l, d-dimer ≥1000 ng/ml, or c-reactive protein (crp) ≥75 mg/l) - during the course of the study starting at screening and for at least 6 months after their final study treatment: - female subjects of childbearing potential must agree to use 2 medically accepted birth control methods - male subjects with a partner who might become pregnant must agree to use reliable forms of contraception (i.e., vasectomy, abstinence), or an acceptable method of birth control must be used by the partner - all subjects must agree not to donate sperm or eggs (ovocytes)

inclusion criteria: - hospitalized with laboratory-confirmed (rt-pcr+) or highly suspected (compatible with at least bilobar lung involvement without another plausible diagnosis) covid-19 - weight ≤100 kg - within 24 hours of reaching a who severity score of 4-6 either: - at admission - while already hospitalized - informed consent obtained from subject/next of kin/legal proxy - primary admitting diagnosis of pneumonia supported by a compatible clinical presentation with a documented infiltrate consistent with pneumonia on chest radiograph or ct as assessed by the admitting emergency-department (ed), clinic, or ward physician or equivalent caregiver - recommended (not mandatory) guidance/discretionary criteria defining patients with pneumonia satisfying all 4 categories below: - at least 2 symptoms: difficulty breathing, cough, production of purulent sputum, or chest pain - at least 2 vital sign abnormalities: fever, tachycardia, or tachypnea (thresholds -- fever: oral or core temperature >100.4 °f [38 °c]; heart rate >100 beats/min; respiratory rate >24/min) - at least one finding of other clinical signs and laboratory abnormalities: hypoxemia (o2 saturation <90%), clinical evidence of pulmonary consolidation, or leukocytosis or leukopenia - chest imaging or ct showing new (or presumed new or worsening) pulmonary infiltrates - principal investigator to note radiologic findings in the electronic case report form (ecrf) - radiology report to be placed in the ecrf - a copy of the radiograph attached to be saved for review - a hyperinflammatory status (defined by increased ferritin ≥500 µg/l, d-dimer ≥1000 ng/ml, or c-reactive protein (crp) ≥75 mg/l) - during the course of the study starting at screening and for at least 6 months after their final study treatment: - female subjects of childbearing potential must agree to use 2 medically accepted birth control methods - male subjects with a partner who might become pregnant must agree to use reliable forms of contraception (i.e., vasectomy, abstinence), or an acceptable method of birth control must be used by the partner - all subjects must agree not to donate sperm or eggs (ovocytes)