Fig. 1: Human antibody and IFNγ responses to N and RBD polypeptides.

a Needle plot indicating the number of amino acid divergence points in the protein sequence of Nucleocapsid (N) and Spike (S) of five variants in relation to the N and S sequences from the SARS-CoV-2 lineage B (Wuhan). The peaks with circles indicate the position of the most frequent amino acid changes. The height of the peaks indicates the frequency of the changes in each divergent point. The blue and purple circles indicate common mutations and those observed on variants of concern, respectively. The sum of the amino acid changes for each segment (S1, RBD, and S2) of the S and N proteins considering the 6 SARS-CoV2 lineages is also shown. The vertical black and red lines below the bars illustrating the N and S polypeptides indicate, respectively, the position of each putative CD4⁺ T and CD8⁺ T cell epitopes identified by in silico epitope prediction. b-g UMAP projection of FACS data showing IFN-γ production by different CD4⁺ (b) or CD8⁺ (c) T cell compartments, determined by the surface markers CD45RO, CD27, and CD69. Data are also represented by the percentage of each subpopulation in total CD4⁺ (d, f) or CD8⁺ (e, g) IFN-γ⁺ T cells. The number of individuals used in these experiments was 5 controls, 8 vaccinated, and 8 convalescents. Statistical analysis of IFN-γ production (f, g) was performed using two-sided Wilcoxon-matched pairs signed rank; “ns” indicate that difference is not statistically significant and NS = non-stimulated PBMCs.