FIGURE 2.

Humoral and cellular CD4⁺ T‐cell response triggered by ChAdOx1, Ad26.CoV2.S, mRNA‐1273 and BNT162b2 in naïve subjects. A total of 292 no‐previously infected (naïve) individuals from Spain were included in our study. They were classified according to their EMA vaccination regimen and the time since full vaccination. (A) The anti‐spike RBD IgG levels in relative units determined by enzyme‐linked immunosorbent assay in plasma from naïve individuals are shown. (B) The neutralizing antibodies titers (10⁸/[free ACE2] in log10 scale) determined by using a competitive immunoassay in plasma from naïve individuals are shown. (C) The proliferation increments of CD4⁺ cells after 5 days of stimulation of peripheral blood mononuclear cells from naïve individuals with SARS‐CoV‐2 peptide pool in vitro are shown. *p < .05; **p < .01; ***p < .001; ****p < .0001 in Kruskal–Wallis with Dunn's multiple post‐hoc test for group comparisons. Data in time curves are expressed as mean ± SEM; AUC, area under the curve; *p < .05; **p < .01; ***p < .001; ****p < .0001 in Tukey's multiple test for time curve comparisons