NAECs from control (no wheeze/no infant RSV infection) and RSV (no wheeze/RSV) children had increased IFNL2 gene and IFN-β protein expression after in vitro RSV 01-2/20 infection compared to NAECs from children with wheeze/no RSV infection and wheeze/RSV phenotypes (Fig. 5, G and H). Here, IFNB1 is linked to infection.