Unlike a previous report that no activation of CD8 T cells was detected in domestic pigs after infection with the highly virulent ASFV strain Armenia08 in terms of Ki67 expression, which is an indicator of proliferation, and T-bet upregulation in the blood and lymphoid organs [26], we detected the apparent upregulation of CD69 on NK cells, B cells, and T cells in the blood, on distinct T cell subsets in the spleen, and on NK cells in the LNs at 5 dpi, showing the early activation of lymphocytes after ASFV infection. This evidence concerns the gene MKI67 and infection.