Fig. 4.

Memory T cell responses following AZ, Moderna, and MVC vaccination. The frequencies of central memory T cells (Tcm) (A–C) and effector memory T cells (Tem) (D–F) in total T (CD3+) cells (A and D), CD8+ T cells (B and E), and CD4+ T cells (C and F) were detected by flow cytometry. The upper panels of Figs. A–F show the percentage of Tcm/Tem populations before vaccination (pre vac) and 4 weeks after the second dose (post 2nd). The lower panels of Figs. A–F show the changes in Tcm and Tem populations in total T, CD8+ T, and CD4+ T cells. The changes in percentage were subtracted from the memory T cell populations prevaccination from those postvaccination. The numbers in each column on the graph are the means for each group. The results are presented as the means ± SD. p < 0.05 (∗), p < 0.01 (∗∗), p < 0.001 (∗∗∗) and p < 0.0001 (∗∗∗∗).