Fig. 1

The percentage of cycling memory CD8⁺ and CD4⁺ T cells increased with disease severity of influenza infection. A, B Percentages of cycling CD8⁺ T cells, cycling CD8⁺ memory and effector T cells in healthy donors (HD, n = 19), moderate patients (M, n = 34) and severe patients (S, n = 27). C, D Percentages of cycling CD4⁺ T cells, cycling CD4⁺ memory and effector T cells in healthy donors and influenza patients. Data are displayed as mean ± SEM. Statistical significance is determined by unpaired t test. *P < 0.05, **P < 0.01, ***P < 0.001