The initial use of IFN-λ in the treatment of viral infections has revealed advantages over the use of IFN-α2a and IFN-α2b, which have been associated with adverse effects such as fatigue, neurologic signs, autoimmune diseases (75), and proinflammatory effects on immune cells in the respiratory tract (52, 53, 76). This evidence concerns the gene IFNA2 and viral infectious disease.