inclusion criteria: * positive diagnosis of sars-cov-2 by real-time rt-pcr in oropharyngeal sample. * 7 days or more after the start of the infection * hospitalized patients with moderate to severe respiratory complications that do not have received mechanical ventilation. * patients receiving standard therapy at the hospital general de méxico eduardo liceaga. * signing of the informed consent form * patients of both sexes (non-pregnant female) 18 years of age or older will be eligible if they have a positive diagnostic sample by rt-pcr, pneumonia confirmed by chest imaging and oxygen saturation (sao2) \< 93% at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) (pao2: fio2) at 300 mg hg or less

inclusion criteria: * positive diagnosis of sars-cov-2 by real-time rt-pcr in oropharyngeal sample. * 7 days or more after the start of the infection * hospitalized patients with moderate to severe respiratory complications that do not have received mechanical ventilation. * patients receiving standard therapy at the hospital general de méxico eduardo liceaga. * signing of the informed consent form * patients of both sexes (non-pregnant female) 18 years of age or older will be eligible if they have a positive diagnostic sample by rt-pcr, pneumonia confirmed by chest imaging and oxygen saturation (sao2) \< 93% at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) (pao2: fio2) at 300 mg hg or less

inclusion criteria: - positive diagnosis of sars-cov-2 by real-time rt-pcr in oropharyngeal sample. - 7 days or more after the start of the infection - hospitalized patients with moderate to severe respiratory complications that do not have received mechanical ventilation. - patients receiving standard therapy at the hospital general de méxico eduardo liceaga. - signing of the informed consent form - patients of both sexes (non-pregnant female) 18 years of age or older will be eligible if they have a positive diagnostic sample by rt-pcr, pneumonia confirmed by chest imaging and oxygen saturation (sao2) < 93% at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) (pao2: fio2) at 300 mg hg or less

inclusion criteria: - positive diagnosis of sars-cov-2 by real-time rt-pcr in oropharyngeal sample. - 7 days or more after the start of the infection - hospitalized patients with moderate to severe respiratory complications that do not have received mechanical ventilation. - patients receiving standard therapy at the hospital general de méxico eduardo liceaga. - signing of the informed consent form - patients of both sexes (non-pregnant female) 18 years of age or older will be eligible if they have a positive diagnostic sample by rt-pcr, pneumonia confirmed by chest imaging and oxygen saturation (sao2) < 93% at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) (pao2: fio2) at 300 mg hg or less