Figure 4.

The identification of CTL epitopes. (A) After identifying the 27 kinds of HLA-I alleles, all the CTLEs of the S protein in the 6 SARS-CoV-2 strains were shown here. The abscissa represents the six virus strains and the ordinate represents the position of the beginning of the epitope peptide. (B) The abscissa represented the position of the beginning of the epitope, and the ordinate represented the frequency of the epitope in the 27 alleles. (C) All epitopes of each virus strain were connected in sequence according to the size of the starting position, and the epitopes that had undergone mutation were in the “pink” box. Through sequence alignment, all the common and variant epitopes of all strains were used for vaccine construction.