CD8A and infectious mononucleosis: In Infectious Mononucleosis (IM), the clinical manifestation of primary EBV infection, CD8 T cells specific for a single EBV immunodominant epitope contained up to 80% of cells in G1 and up to 20% of TDS cells, whereas corresponding cells in healthy EBV carriers contained about 5% of cells in G1 and 0% TDS.