Strikingly, we found that infection of Calu-3 cells with BA.4 and BA.5 resulted in significantly less innate immune activation compared to BA.1/BA.2, evidenced by lower induction of IFNβ (IFNB) and interferon stimulated genes (ISGs) including inflammatory chemokine CXCL10 and RSAD2, DDX58, IFIT1 and IFIT2 (Fig. 1d and Extended Data Fig. 2c–g) and a trend towards reduced MX1 and MX2 expression (Fig. 1d). This evidence concerns the gene IFNB1 and infection.