Patients >/= 18 years old diagnosed with COVID-19 (as evaluated by PCR test confirming infection with SARS-CoV-2) will be eligible for inclusion if they meet all of the below criteria. Inclusion criteria must all be present within a 24-hour time period at the time of enrollment: 1. Patient currently hospitalized 2. Aged ≥ 18 years 3. Willing and able to provide written informed consent, or with a legal representative who can provide informed consent 4. Peripheral capillary oxygen saturation (SpO2) ≤ 94% at room air, or requiring supplemental oxygen at screening 5. PaO2/FiO2 ratio < 300 mmHg 6. Bilateral infiltrates on frontal chest radiograph or bilateral ground glass opacities on a chest CT scan 7. Hypoxemia requiring an increase in the fraction of inspired oxygen (FiO2) of ≥ 20% AND an increase in positive end-expiratory airway pressure (PEEP) level of 5 cm H2O or more to maintain transcutaneous oxygen saturations in the target range of 88-95%, or requirement for escalation from oxygen therapy to invasive mechanical ventilation

1. PaO2/FiO2 ≥ 300 at the time of enrollment 2. A previous MSC infusion not related to this trial 3. History of Pulmonary Hypertension (WHO Class III/IV) 4. History of left atrial hypertension or decompensated left heart failure. 5. Pregnant or lactating patient 6. Unstable arrhythmia 7. Patients with previous lung transplant 8. Patients currently receiving chronic dialysis 9. Patients currently receiving Extracorporeal Membrane Oxygenation (ECMO) 10. Presence of any active malignancy (except non-melanoma skin cancer) 11. Any other irreversible disease or condition for which 6-month mortality is estimated to be greater than 50% 12. Moderate to severe liver disease (AST and ALT >5 X ULN) 13. Severe chronic respiratory disease with a PaCO2 > 50 mm Hg or the use of home oxygen 14. Baseline QT prolongation 15. Moribund patient not expected to survive > 24 hours