Importantly, M198–206-specific CD8+ T cells were detected with significantly higher frequency at the periphery of convalescents suffering moderate/severe COVID-19 from late 2020 through early 2022, consistent with the reports demonstrating M protein as well conserved viral protein among various SARS-CoV-2 strains (https://nextstrain.org/ncov/gisaid/global). This evidence concerns the gene CD8A and COVID-19.