Pregnancy or lactation. Participation in another interventional clinical study capable of altering the patient's response to the application of vascular stromal fraction. Patients with viral infections by other etiologic agents that are not SARS-CoV-2. Other diseases affecting the respiratory tract with negative testing for COVID-19. Body mass index (BMI) under 20 and over 40 kg / m2. Presence of active malignancy (except non-melanoma skin cancer). Venous thromboembolism receiving anticoagulation currently or in the last 3 months. Patient receiving extracorporeal life support (ECMO). Patient with thrombocytopenia. Number of platelets inferior to 100,000 plaq / µL. Patients with severe chronic liver disease (Child-Pugh 12 or above). Patients in palliative care.

Pregnancy or lactation. Participation in another interventional clinical study capable of altering the patient's response to the application of vascular stromal fraction. Patients with viral infections by other etiologic agents that are not SARS-CoV-2. Other diseases affecting the respiratory tract with negative testing for COVID-19. Body mass index (BMI) under 20 and over 40 kg / m2. Presence of active malignancy (except non-melanoma skin cancer). Venous thromboembolism receiving anticoagulation currently or in the last 3 months. Patient receiving extracorporeal life support (ECMO). Patient with thrombocytopenia. Number of platelets inferior to 100,000 plaq / µL. Patients with severe chronic liver disease (Child-Pugh 12 or above). Patients in palliative care.