Fig. 4: cAd3-Ebola vaccination increased the proportion of CD4+ and CD8 + T cells responding to Zaire epitopes by week 4.

Percentage of memory background-subtracted CD4 (a, b) and CD8 (c, d) T cells responding to ex vivo stimulation with production of any tested cytokine at baseline and four weeks post cAd3-Ebola vaccination in Trial US (a, c) and Trial UG (b, d) participants. Box plots denote median with upper and lower quartiles of each group. Dotted line indicates background cytokine production in the absence of stimulation. Each ⥉ in (a, c) indicates a single data point greater than the extent of the y axis : one participant displayed high baseline frequencies between 20 and 25% of GP-reactive memory CD4 and CD8 T cells, that diminished to less than 1% after vaccination; four weeks after vaccination, GP reactivity reached 2.7% of memory CD4 T cells in one individual and 6.9% of memory CD8 T cells in a separate individual. For each group, titers were compared between baseline and week 4 using the Wilcoxon rank-sum test, and statistical significance is reported above each group for which p < 0.05. Results from (a, c) are from a previous clinical trial (NCT02231866), and the results have been partially reported^28,32.