inclusion criteria: 1. have had a positive test confirming the diagnosis of covid-19; 2. have had clinical signs of severe acute respiratory syndrome or pneumonia (dyspnea, cough, with need for oxygen support at the time of enrollment); 3. have visible consolidations/ground glass opacities on chest x-ray or computed tomography; 4. have been on ventilator support for no longer than 5 calendar days prior to the schedule date of delivery of low-dose radiation therapy; 5. they voluntarily participate in this clinical trial, gave informed consent and signed the informed consent form.

inclusion criteria: 1. have had a positive test confirming the diagnosis of covid-19; 2. have had clinical signs of severe acute respiratory syndrome or pneumonia (dyspnea, cough, with need for oxygen support at the time of enrollment); 3. have visible consolidations/ground glass opacities on chest x-ray or computed tomography; 4. have been on ventilator support for no longer than 5 calendar days prior to the schedule date of delivery of low-dose radiation therapy; 5. they voluntarily participate in this clinical trial, gave informed consent and signed the informed consent form.

inclusion criteria: have had a positive test confirming the diagnosis of covid-19; have had clinical signs of severe acute respiratory syndrome or pneumonia (dyspnea, cough, with need for oxygen support at the time of enrollment); have visible consolidations/ground glass opacities on chest x-ray or computed tomography; have been on ventilator support for no longer than 5 calendar days prior to the schedule date of delivery of low-dose radiation therapy; they voluntarily participate in this clinical trial, gave informed consent and signed the informed consent form.

inclusion criteria: have had a positive test confirming the diagnosis of covid-19; have had clinical signs of severe acute respiratory syndrome or pneumonia (dyspnea, cough, with need for oxygen support at the time of enrollment); have visible consolidations/ground glass opacities on chest x-ray or computed tomography; have been on ventilator support for no longer than 5 calendar days prior to the schedule date of delivery of low-dose radiation therapy; they voluntarily participate in this clinical trial, gave informed consent and signed the informed consent form.