Figure 2.

AM15 HA‐specific B memory cell numbers increase following booster vaccination in healthy controls. (a) Gating strategy to discriminate B cells from T cells, followed by selection of CD38^dim B cells in which naïve and memory subsets were distinguished using IgM and CD27. Similarly, within CD38^dim HA‐specific (HA⁺) B cells (Figure 1), naïve and memory subsets were defined. (b) Serum HA‐specific IgG levels pre‐ and post‐booster vaccination as measured by ELISA. (c) Total memory B (Bmem) cell numbers pre‐ and post‐booster vaccination. (d) HA⁺ Bmem cell numbers pre‐ and post‐booster. Statistics were performed with the Wilcoxon matched‐pairs signed rank test; ** P < 0.01.