In our opinion, the self-limited mild symptoms of the two COVID-19 patients infected with KMUH-1 and KMUH-2 with the spike 68-76del+spike 675-679del double-deletion variation in this study might have resulted from the combination of the effects of spike 68-76del and 675-679del variations due to its lower infection rate compared to wild-type virus and increased susceptibility to IFN-α2 induced upon infection. Here, IFNA2 is linked to infection.