Figure 3.

Predominant IgG1 response in AM15 HA‐specific B cell memory in healthy controls. (a) Schematic of the constant gene regions in the human IGH locus depicting their relative positioning with respect to the rearranged VDJ exon encoding the variable domain. (b) Gating strategy to delineate IgM⁺, IgG1⁺, IgG2⁺, IgG3⁺, IgG4⁺ and IgA⁺ CD19⁺ CD38^dim memory B cells (Bmem) and their median cell numbers pre‐ and post‐vaccination. (c) Gating strategy to delineate IgM⁺, IgG1⁺, IgG2⁺, IgG3⁺, IgG4⁺ and IgA⁺ CD19⁺ CD38^dim HA‐specific (HA⁺) Bmem and their median cell numbers pre‐ and post‐vaccination. (d) HA⁺ IgG1⁺ Bmem cell numbers pre‐ and post‐vaccination (e) Frequencies of HA⁺ Bmem cells expressing CD27 pre‐ and post‐booster vaccination. Statistics were performed with the Wilcoxon matched‐pairs signed rank test; * P < 0.05, ** P < 0.01.