Figure 3. Correlation between age and H1N1-specific Memory B cells and plasmablasts response in HIV (Black) and HC (Grey). (A) Evaluation of the H1N1 specific memory B cells at T0 and T2. Lines represent mean ±SEM. For comparisons between age groups at same time point, Mann-Whitney test was performed and for comparisons between time points of the same age group, Wilcoxon signed-rank test was performed; *, Statistical significance at p <0.05. (B) Age was correlated with (Top) H1N1 specific memory B cells at T0 assessed with ELISpot using PBMC pre vaccination stimulated for 5 days with H1N1 (5µg/ml) and (Bottom) H1N1 specific memory B cells at T2 assessed with ELISpot using PBMC 21 days after vaccination stimulated for 5 days with H1N1 (5µg/ml) in (Left) 60 Healthy controls and (Right) 64 HIV infected individuals. ELISpot values are expressed as log2 scale. Age groups depicted as squares (young, <40 years), triangles (middle, 40-59 years) and circles (old, ≥60 years). Spearman correlation was performed.