CD8A and viral infectious disease: The GII.2 and GII.4 VLP-specific CD8+ T-cell responses observed in subject CH04 were dominated by high-expression frequencies of IL4, a cytokine that helps drive the differentiation of naïve T cells toward a Th2 lineage, proliferation of lymphocytes, B-cell class-switching, and the development of humoral and mucosal immune responses, all of which would be expected during a primary viral infection of the intestinal mucosa.