* patients evaluated as severe or critically severe type of covid-19 infection (individuals who have spo2 \<94% on room air, oxygen treatment is necessary, respiratory failure, septic shock, and/or multiple organ dysfunction). * patients with comorbidities * decline to participate by parents or children * allergy to any study medication or usage of any kind of interferon treatment within 14 days before test * children cannot tolerate the inhalation treatment * any situation where the program cannot be carried out safely.

* patients evaluated as severe or critically severe type of covid-19 infection (individuals who have spo2 \<94% on room air, oxygen treatment is necessary, respiratory failure, septic shock, and/or multiple organ dysfunction). * patients with comorbidities * decline to participate by parents or children * allergy to any study medication or usage of any kind of interferon treatment within 14 days before test * children cannot tolerate the inhalation treatment * any situation where the program cannot be carried out safely.

patients evaluated as severe or critically severe type of covid-19 infection (individuals who have spo2 <94% on room air, oxygen treatment is necessary, respiratory failure, septic shock, and/or multiple organ dysfunction). patients with comorbidities decline to participate by parents or children allergy to any study medication or usage of any kind of interferon treatment within 14 days before test children cannot tolerate the inhalation treatment any situation where the program cannot be carried out safely.

patients evaluated as severe or critically severe type of covid-19 infection (individuals who have spo2 <94% on room air, oxygen treatment is necessary, respiratory failure, septic shock, and/or multiple organ dysfunction). patients with comorbidities decline to participate by parents or children allergy to any study medication or usage of any kind of interferon treatment within 14 days before test children cannot tolerate the inhalation treatment any situation where the program cannot be carried out safely.