IFNA1 and bronchiolitis: These deficiencies in IFN responses in males were mirrored by significantly higher incidence of hospital admissions due to severe LRTIs in early life (which are almost exclusively viral in aetiology) among male participants in our cohort, as well as substantially higher prevalence of RSV-positive bronchiolitis, a disease with a peak incidence at 4.5 months of age26.