Flow cytometric analysis showed that BVDV-infected mice had reduced percentage of CD3+ (CP BVDV, p < 0.0001, Figure 8A; NCP BVDV, p < 0.0001, Figure 8A), CD4+ (CP BVDV, p < 0.0001, Figure 8B; NCP BVDV, p < 0.0001, Figure 8B), and CD8+ (CP BVDV, p < 0.0001, Figure 8C; NCP BVDV, p < 0.0001, Figure 8C) T cells at day 7 of post-infection compared to the mock-infected mice. This evidence concerns the gene CD4 and infection.