Autosomal recessive (AR) complete IFNAR1 deficiency has been shown to underlie adverse reactions to vaccination with live-attenuated viruses (LAV), including measles–mumps–rubella (MMR) and yellow fever (YF) (Hernandez et al., 2019; Bastard et al., 2022a; Gothe et al., 2022). The gene discussed is IFNAR1; the disease is viral infectious disease.