Since IFN-α2 has been reported to be associated with several autoimmune diseases [31], and due to the absence of any empirical data on IFN-α2 intranasal application for hospitalized patients with COVID-19-associated pneumonia at the time of the current project, a recommended-by-manufacturer dose of IFN-α2 (80,000 IU daily) was used. This evidence concerns the gene IFNA2 and susceptibility to pneumonia measurement.