* receiving ventilatory or respiratory support (invasive or non-invasive mechanical ventilation or high flow nasal cannula) or supplemental oxygen with fio2\>0.35 * requiring intensive care due to acute covid-19 pneumonia or its complications * having a known lung parenchymal lung disease before the onset of covid-19 * pregnant or lactating women * having absolute contraindication for prednisolone in a dose of 40 mg/day (this includes untreated glaucoma, uncontrolled diabetes mellitus, signs of an uncontrolled or untreated infection or sepsis, pulmonary mycosis, untreated severe psychiatric disorders) * unwilling to provide informed consent

* receiving ventilatory or respiratory support (invasive or non-invasive mechanical ventilation or high flow nasal cannula) or supplemental oxygen with fio2\>0.35 * requiring intensive care due to acute covid-19 pneumonia or its complications * having a known lung parenchymal lung disease before the onset of covid-19 * pregnant or lactating women * having absolute contraindication for prednisolone in a dose of 40 mg/day (this includes untreated glaucoma, uncontrolled diabetes mellitus, signs of an uncontrolled or untreated infection or sepsis, pulmonary mycosis, untreated severe psychiatric disorders) * unwilling to provide informed consent

- receiving ventilatory or respiratory support (invasive or non-invasive mechanical ventilation or high flow nasal cannula) or supplemental oxygen with fio2>0.35 - requiring intensive care due to acute covid-19 pneumonia or its complications - having a known lung parenchymal lung disease before the onset of covid-19 - pregnant or lactating women - having absolute contraindication for prednisolone in a dose of 40 mg/day (this includes untreated glaucoma, uncontrolled diabetes mellitus, signs of an uncontrolled or untreated infection or sepsis, pulmonary mycosis, untreated severe psychiatric disorders) - unwilling to provide informed consent

- receiving ventilatory or respiratory support (invasive or non-invasive mechanical ventilation or high flow nasal cannula) or supplemental oxygen with fio2>0.35 - requiring intensive care due to acute covid-19 pneumonia or its complications - having a known lung parenchymal lung disease before the onset of covid-19 - pregnant or lactating women - having absolute contraindication for prednisolone in a dose of 40 mg/day (this includes untreated glaucoma, uncontrolled diabetes mellitus, signs of an uncontrolled or untreated infection or sepsis, pulmonary mycosis, untreated severe psychiatric disorders) - unwilling to provide informed consent