“…Specifically, the prevalence of autoAbs neutralizing the IFN-I cytokines IFNα and/or IFNω increases sharply with age in apparently healthy individuals, such that a conservative estimate of prevalence in those >70 years old is about eight times higher (1.4%) than that in younger individuals (0.17%) ( Bastard et al, 2021 ). Furthermore, the presence of neutralizing anti-IFN-I autoAbs in individuals has been associated with an increased susceptibility to severe infections caused by several viral pathogens, including SARS-CoV-2 ( Akbil et al, 2022 ; Bastard et al, 2020 , 2024b ; Busnadiego et al, 2022 ; Chauvineau-Grenier et al, 2022 ; Credle et al, 2022 ; Eto et al, 2022 ; Frasca et al, 2022 ; Goncalves et al, 2021 ; Manry et al, 2022 ; Mathian et al, 2022 ; Scordio et al, 2022 ; Solanich et al, 2021 ; Troya et al, 2021 ; Wang et al, 2021 ), MERS-CoV ( Alotaibi et al, 2023 ), influenza A virus ( Zhang et al, 2022 ), West Nile virus ( Gervais et al, 2023 ; Lin et al, 2023 ), and various herpesviruses ( Bayat et al, 2015 ; Burbelo et al, 2010 ; Busnadiego et al, 2022 ; Hetemaki et al, 2021 ; Mathian et al, 2022 ; Mogensen et al, 1981 ; Pozzetto et al, 1984 ). Given that >100 million people worldwide have been estimated to harbor neutralizing anti-IFN-I autoAbs ( Bastard et al, 2024a ) and are therefore at increased risk of severe infectious disease outcomes, it is critical to understand factors associated with their development and pathogenic mechanisms to inform future mitigation strategies.…”