IFNA2 and COVID-19: The other major finding related to age-dependent differences in the IFN response found reduced IFNα secretion by pDCs in adults with severe COVID-19 [159], and patients with autoimmune polyendocrine syndrome type-1 (APS-1) which produces autoantibodies against type I IFNs are at increased risk of severe disease [158], and require mechanical ventilation [160].