Figure 1.

Evaluation of influenza-specific CD4⁺ and CD8⁺ T-cell immunity among influenza A/H3N2- and influenza B-infected patients at influenza diagnosis and Day 28. IFN-γ: interferon-γ; TNF-α: tumor-necrosis factor-α; IL: interleukin. Results were expressed as number of cytokine-producing CD4⁺ cells/10⁶ CD4⁺ T-cells or CD8⁺ cells/10⁶ CD8⁺ T-cells. For data presentation, cell frequencies labelled as TNFα⁺, IFNγ⁺, IL2⁺ or IL4⁺ were cells producing the given cytokine, regardless of the production of other cytokines. The upper edge of the box represents the median value, and the error bars represent the interquartile range. Red and blue dots represent individual patient frequencies at influenza diagnosis and Day 28, respectively.