FIG 4.

Memory subsets of proliferated (CFSE^dim) CD4⁺ T cells of aP- and wP-primed children cross-sectionally sampled before (A) and 10 days after (B) booster vaccination are presented. The proportions of naive T cells (CCR7⁺ CD45RA⁺; purple), central memory T cells (T_CM) (CCR7⁺ CD45RA⁻; magenta), effector memory T cells (T_EM) (CCR7⁻ CD45RA⁻; yellow), and terminally differentiated T cells (T_TD) (CCR7⁻ CD45RA⁺; black) specific for PT, FHA, and Prn antigens are shown. (C) The ratio of the fraction of proliferated (CFSE^dim) T_EM (yellow in panels A and B) in antigen-stimulated cultures to individual nonstimulated cultures is shown.