Fig. 8

Production of effector memory T cells (T_EM) after intranasal boost immunization in the lung and spleen in Study 2. At 10 days post-3rd immunization, lung and spleen samples were collected and subjected to flow cytometry analysis to determine the percentages of CD44⁺CD62L⁻ T_EM cells, CD44⁺CD62L⁺ T_CM cells and CD44⁻ CD62L⁺ T_Naive cells in the lung CD4 (A–C), lung CD8 (D–F), spleen CD4 (G–I) and spleen CD8 (J–L) subgroups. (n = 4, *P < 0.05, **P < 0.01, ***P < 0.001, ns: not significant)