We observed that DENV2-elicited CD8+ T cells mainly recognized epitopes in ZIKV NS3, NS5, prM and E, and that these cross-reactive CD8 T cell responses dominated during ZIKV infection in Ifnar1−/−and WT C57Bl/6 mice with Ifnar1 blockade (via pre-treatment with blocking anti-Ifnar1 Ab). This evidence concerns the gene CD8A and Zika virus infectious disease.