IFNAR1 and infection: Infection assays demonstrated that the viral titers of H1N1, H3N2, and B/Victoria vaccine strains were increased by 3.3-, 3.9-, and 4.1-fold, respectively, in IFNAR1-KO cells relative to WT cells, indicating that IFNAR1 deletion enhances the replication of various influenza virus subtypes commonly used in vaccine production.