Fig. 4
The kinetic of memory B cell responses to SARS-CoV-2 RBD protein and correlation with RBD-specific T cell responses after vaccination. A Experimental design for differentiation of memory B cells into antibody secreting cells. B, C Comparative memory B cells ELISpot spot forming units (SFUs) per 5 × 105 PBMC in individuals with unvaccination, and vaccination with SARS-CoV-2 RBD. D ELISA detected anti-RBD IgG secreted by RBD-specific memory B cells from cultural supernatant. responder (resp) cut-off is 0.36 (dotted line). E–G Heatmap showing associations among AIM+CD4, AIM+CD8, Th1, Th2, memory B cells, IgG, IgM, and IgA on day 40 (E), 180 (F), and 60 (G) after vaccination. Colours indicated the level of correlation (red– positive, white—no correlation, blue—negative). *: P < 0.05, **: P < 0.01, ***: P < 0.001, ns: no significance. Significant difference was calculated by Kruskal–Wallis’s test