Fig. 5

Correlations between interferon (IFN)-γ, tumor necrosis factor (TNF), interleukin (IL)-2, IL-6, and IL-10 levels. Correlations between IFN-γ, TNF, IL-2, IL-6, and IL-10 levels at (a) six months after primary vaccination and (b) three months after booster vaccination. rS: Spearman rank correlation coefficient. Values of rS are shown in bold when P values are less than 0.05: * P<0.05, ** P<0.01, and *** P<0.001. The levels of each cytokine are logarithmically transformed. The 90% confidence ellipse region was drawn assuming a near-Gaussian distribution of the values