IRCT20160809029275N1 IRCT 2020-05-30 Mashhad University of Medical Sciences stem cell therapy in Covid-19 Evolution of Allogenic Mesenchymal stem cell- derived Umbilical cord transplantation for ARDS patients infected with COVID19. 2020-06-14 anticipated 20 Complete https://irct.ir/trial/48187 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: Simple randomization. Eligible patients randomly and without considering a specific factor are divided into two groups: intervention and control.In this method, the random number table is used .So that people with individual codes are allocated in a group and people with couple codes are allocated in the other group.This method of randomization is performed to remove bias, Blinding description: No information will be provided to clinical caregivers and evaluators about which group got the cell and which one has not taken a cell.This method of blinding is performed to remove bias. 2-3 Covid-19 disease. Intervention 1: Intervention group: Group receiving mesenchymal stem cells. In this group, patients in 3 times (1, 3 and 6 days) are received 1 million Umbilical core-derived MSCc/BW by intravenous injection ( Through the catheter and the Central vein and from the superior vena cava vein ). Also, in addition to cell therapy,Other common treatments will be given to patients according to the physician's supervision.Mesenchymal Stem cells had an ISCT standard and were given from a healthy donor. Blood samples were given from patients on days 0, 2, and 7, as well as 14 days after the second injection and patients will follow for 20 days (in terms of clinical and immunological parameters).It should be noted that of all patients at the beginning of the study conscious consent form will be received. Intervention 2: Control group: Receiving common therapies (without stem cell). In this group, patients are received other common treatments including antiviral drugs and etc In accordance with the physician's opinion and do not receive stem cells. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is There is no more information