CD8A and infection: Mechanisms proposed to contribute to impairment of T cell-mediated control of viral replication during acute/early infection include virus mutational escape from CD8+ T cell responses [4,7], reduction in the functional avidity of CD8+ T cell responses (possibly due to the exhaustion and deletion of higher avidity T cell clones [8,9]) and acquisition of defects in the functional capacity of HIV-specific T cells [10-14].