Parameters associated with vaccination responses. Univariate analyses of (A) vaccination response parameters, (B) clinicodemographic features, and (C) immune signatures in study participants based on CD4⁺ T-cell, CD8⁺ T-cell, and IgG responses. (left) Groups of study participants with detectable spike-specific CD4⁺ response (n = 144) compared with those without detectable CD4⁺ response (n = 77). Analogously, (middle) comparison of participants with spike-specific CD8⁺ response (n = 76) with CD8⁺ nonresponders (n = 145); (right) participants with specific IgG levels above median (n = 109) vs participants with lower spike-specific IgG (n = 110). Each line represents a vaccination response parameter, clinicodemographic feature, or specific population from in-depth immunophenotyping (expressed as cells per μL). Green cells denote higher age, higher IgG titers, higher percentages of women, and of recipients of heterologous vaccination schemes, as well as higher cell numbers per μL blood for all other features in CD4⁺, CD8⁺, and IgG responders. Red cells indicate lower respective values in responders. Shown are all parameters with at least 1 of the 3 P values < .05 and for comparison, also the percentage of patients under active treatment. A total of 121 immunophenotypic parameters were analyzed. CD4_pos/neg, with/without detectable spike-specific CD4⁺ T-cell response; CD8_pos/neg, with/without detectable spike-specific CD8⁺ T-cell response; CM, central memory; CoV2Sc, after stimulation with spike peptides; cytokine⁺, polyfunctional activated T cells; DN, CD4⁻CD8⁻ double-negative T cells; DP, CD4⁺CD8⁺ double-positive T cells; EM, effector memory; IgG_pos/neg, with/without spike-specific IgG levels above median; TE, terminal effector.