<p>(A) Representative flow cytometry plots of CD25<sup>+</sup>OX40<sup>+</sup> upregulation by CD4<sup>+</sup> T cells in naïve (CD45RA<sup>+</sup>CCR7<sup>+</sup>; lower panel) and antigen-experienced memory (excluding naïve cells; upper panel) cells after stimulation with TT-megapool [TT (MP)], Tetanus Toxoid [TT (ag)], Dengue virus-megapool [DV (MP)], or PHA as a positive control. (B) Median CD25<sup>+</sup>OX40<sup>+</sup> expression by CD4<sup>+</sup> memory T cells after 24 hours. Each dot represents one donor originally primed with DTwP vaccine and not recently boosted. Kruskal-Wallis multiple comparison test, *, <i>p</i><0.05. (C and D) Percentage IFNγ- (C) or IL-4-producing (D) CD4<sup>+</sup> memory T cells in response to TT megapool, or PMA/Ion.</p
