1. Patient who gives his informed consent. 2. Negative viral load by PCR. 3. Over 18 and under 75. 4. Lung damage evidenced by the criteria of radiological severity in COVID 19 on CT.

1. Patient who gives his informed consent. 2. Negative viral load by PCR. 3. Over 18 and under 75. 4. Lung damage evidenced by the criteria of radiological severity in COVID 19 on CT.