ST6GAL1 and influenza: In contrast, defining influenza infection more loosely based on whether a participant reported having flu-like symptoms in the 2019–2020 or 2020–2021 flu seasons (43,956 cases versus 250,673 controls) led to attenuated effect sizes but still highly significant associations: OR = 0.93 and P = 1.7 × 10−7 for ST6GAL1, and OR = 0.95 and P = 4.0 × 10−11 for B3GALT5 (Fig. 2).