Conducting preclinical studies of mRNA vaccines is complicated by the lack of relevant animal models of the human immune system. Immunocompetent mice are widely used in biomedical research. However, critical differences in the genetics and immune system of mice and humans prevent the study of unique human immune responses in mice. Within the framework of this work, the possibility of modeling the cytotoxic T-cell response to mRNA vaccines encoding the S-protein of the SARS-CoV-2 virus was investigated. High-affinity peptides from S-protein were analyzed for the most frequent allelic variants of human MHC-I, two immunocompetent mouse lines (C57BL/6, BALB/c) and an outbred mouse model of IRC. The results of computer modeling have shown that mouse models can be used in preclinical studies of mRNA vaccines against SARS-CoV-2. Mouse MHC-I is able to present virus peptides that are highly affine for human MHC-I. Moreover, the immunogenicity of some of them has already been confirmed by examining blood samples from patients who have had COVID-19.