CD8A and Zika virus infectious disease: Day 3 post ZIKV challenge was chosen for analysis of the T cell and viral phenotype to focus our study on the adaptive memory but not primary T cell response; this decision was based on prior studies demonstrating that the CD8+ T cell response to primary DENV or ZIKV infection in mice is not observed on day 3 but becomes detectable after day 5 of infection39–41.