Patients with autosomal recessive (AR) deficiency of IFNAR2 and subsequently IFNAR1 were first recognized by their susceptibility to severe viral diseases precipitated by the exposure to live-attenuated viral vaccines (LAV)—specifically, the measles, mumps, and rubella (MMR) and yellow fever vaccines (Bastard et al., 2021b; Duncan et al., 2015; Gothe et al., 2020; Hernandez et al., 2019; Passarelli et al., 2020). This evidence concerns the gene IFNAR2 and viral infectious disease.