Fig. 6
Post-vaccination cytokine levels. The serum IL-2 (a), IL-4 (b), IL-10 (c), IL-17 (d), IFN-γ (e), and TGF-β1 (f) levels at 2 weeks after booster vaccination. Different superscripts (a, b) indicate a significant difference (P < 0.05). The same superscript indicates no significant difference (P > 0.05). The unit of TGF-β1 concentration was ng/ml, and the concentration unit of other cytokines was pg/ml