CD8A and viral infectious disease: On the contrary, HCMV and EBV-specific CD8 T cell frequency was remarkably constant during the different phases of acute heterologous viral infections and the observed mild proliferation of HCMV and EBV specific CD8 T cells (Figure 3 A and Supplementary Figure S2) might represent a compensatory mechanism counteracting the attrition exerted by the expansion of CD8 T cell specific for the acutely infected virus [30], [34].