CD8A and viral infectious disease: Besides, more detailed studies are required to fully characterize the impact of TCR–pMHC affinity/avidity on the ability of CD8 T cells to develop distinct cytokine profiles (e.g., TH1 versus TH2) (131) or polyfunctional responses, a well-established and important indicator of the ability of CD8 T cells to control viral infections, as suggested in various models (160).