To study the response to mRNA vaccines in SARS-CoV-2 naive individuals with type I IFN deficiencies, we first assessed a cohort of 13 patients with APS-1 (median age: 9, range 2–18 yr) and detectable neutralizing auto-Abs against IFN-α and -ω, and another cohort of eight patients with age-associated autoantibodies (AABs) to IFN-α and/or ω (median age: 63, range 43–76 yr; 3/8 neutralized IFN-α only, 2/8 IFN-ω only, and 3/8 both at 100 pg/ml; Fig. 1 A and Fig. S1, A and B; and see Table S1 A). The gene discussed is DDX41; the disease is autoimmune polyendocrine syndrome type 1.