Proportions of patients with auto-Abs neutralizing type I IFNs by sex and age in 13 cohorts from five countries. (A) Prevalence of individuals with auto-Abs neutralizing at least one type I IFN at a concentration of 100 pg/ml (IFN-α2 and IFN-ω) or 1 ng/ml (IFN-β) in the three groups of individuals infected with WNV (WNVIC, WNVF, and WNVD), by sex. (B) Prevalence of individuals with auto-Abs neutralizing at least one type I IFN at a concentration of 100 pg/ml (IFN-α2 and IFN-ω) or 1 ng/ml (IFN-β) in the three groups of WNV-infected individuals (WNVIC, WNVF, and WNVD), by age class.