Figure 3. Correlations among IFN-γ-secreting Cellular Responses Measured by ELISpot, and T-cell Activation Responses among Vaccine Recipients.

Values in the upper triangle indicate the Spearman's correlation coefficients for each pair of immune responses. Curves in the diagonal entries indicate the density distribution of each immune response. Plots in the lower triangle indicate the joint distribution of each pair of immune responses with a fitted simple linear regression line.