Different explanations were discussed such as immunity, maturation of the immune system, less comorbidities as well as changes of the ACE2 receptors in the respiratory system [22,24].Thus, Bunyavanich et al. [25] found a significant increase of the ACE2 gene expression in the nasal epithelium with increasing age, suggesting higher predisposition for severe infection in adults than children. The gene discussed is ACE2; the disease is infection.