inclusion criteria: * ability to understand the study objectives and risks and provide signed and dated informed consent; * covid-19 infection (by pcr or antibody test or high probability of covid-19 by ct); * pneumonia requiring hospitalization, and oxygen saturation of \<93%, need for noninvasive ventilation. the confirmed volume of lung damage by ct; * ability to proceed with inhalation by self;

inclusion criteria: * ability to understand the study objectives and risks and provide signed and dated informed consent; * covid-19 infection (by pcr or antibody test or high probability of covid-19 by ct); * pneumonia requiring hospitalization, and oxygen saturation of \<93%, need for noninvasive ventilation. the confirmed volume of lung damage by ct; * ability to proceed with inhalation by self;

inclusion criteria: - ability to understand the study objectives and risks and provide signed and dated informed consent; - covid-19 infection (by pcr or antibody test or high probability of covid-19 by ct); - pneumonia requiring hospitalization, and oxygen saturation of <93%, need for noninvasive ventilation. the confirmed volume of lung damage by ct; - ability to proceed with inhalation by self;

inclusion criteria: - ability to understand the study objectives and risks and provide signed and dated informed consent; - covid-19 infection (by pcr or antibody test or high probability of covid-19 by ct); - pneumonia requiring hospitalization, and oxygen saturation of <93%, need for noninvasive ventilation. the confirmed volume of lung damage by ct; - ability to proceed with inhalation by self;