Fig. 4

Kinetics of cytokine production. The leftmost panels show the percentage of individuals in the Junior and Senior groups that secreted cytokines after stimulation with HbSAg: a IFN-γ, (E) TNF-α, (I) IL-5, (M) IL-4, and (Q) IL-2 at various time points. (&) indicate time points with ≥10% differences between Juniors and Seniors after the second immunization. In subsequent panels in each row, the percentage of Seniors producing cytokines after stimulation was analyzed by the route of vaccination (IM and SC) b, f, j, n and r, sex (females and males) c, g, k, o and s and age subsets (65–74 and ≥ 75 years) d, h, l, p and t). Vaccination days are indicated with red triangles at the bottom of the Fig. IM: Intramuscular SC: Subcutaneous. F: Females; M: males. (+) indicate time points with ≥10% differences between Senior subsets after the second immunization