At day 28 PI, the immune response was significantly greater in ICP22 null virus infection than in KOS virus infection for the following immune infiltrates: CD8+IL-4+ (8.4% vs. 3.0%, P < 0.001; Fig. 6B), CD8+GrzB+ (15.7% vs. 11.3%, P < 0.01; Fig. 6F), CD8+IFN-γ+ (7.9% vs. 3.7%, P < 0.001; Fig. 6C), CD8+IFN-α+ (5.3% vs. 2.1%, P < 0.001; Fig. 6D), CD8+GrzA+ (17.1% vs. 9.4%, P < 0.01; Fig. 6E), and CD8+CD25+ (19.8% vs. 12.8%, P < 0.05; Fig. 6H). This evidence concerns the gene IL4 and viral infectious disease.