RIGI and infection: Similar inductions of melanoma differentiation associated protein 5 (MDA5) and its transcript IFIH1 (Fig. 2G and H, respectively) and DDX58 transcripts (Fig. 2I) further confirmed a strong activation of interferon-stimulated genes (ISGs) in B.6 and B.1.1.8 infections and modest induction in Alpha, but insignificant induction in Delta and B.1.36.29 infections.