Fig. 1

Humoral and cellular responses elicited by mRNA and adenoviral vector-based COVID-19 vaccines. Each circle indicates one subject. Blue circles represent subjects who received two doses of mRNA vaccine (n = 16), and red circles represent subjects who received the adenoviral vector-based (J&J) vaccine (n = 17). The dot plots show A anti-RBD IgG antibody levels, B neutralizing titers expressed as NT50 (reciprocal dilution of plasma yielding 50% neutralization of live SARS-CoV-2 virus), and C frequency (%) of RBD-specific B cells. B cells (CD19⁺CD20⁺) were analyzed for RBD specificity utilizing dual fluorescent labeling of RBD tetramers. D IFNγ (pg/ml) production by antigen-specific T cells. PBMCs from each subject were stimulated with a megapool of overlapping synthetic peptides (15-mers) covering the entire Spike (S) antigen. Supernatants were collected after 24 h of stimulation. In all panels, the solid black lines represent the median and interquartile range. Statistical analyses were conducted by the Mann-Whitney U test for unpaired samples (**p ≤ 0.01; ***p ≤ 0.001; ns, non-significant, p > 0.05)