IGHG3 and influenza: In a multivariate regression model, none of the antibody features tested were significantly associated with more favorable d5 ordinal outcomes in patients with severe B/Yamagata influenza, although HA-specific IgG3 (OR = 1.42), FcγRIIa-binding antibody (OR = 1.29), and FcγRIIIa-binding antibody (OR = 1.61) still had OR values greater than 1 in the adjusted model (Figure 6D; left side of heatmap).