CD8A and infection: However, recurrent homologous boosting preserves numerical stability and increases phenotypic and functional complexity of the memory CD8 T cell pool (94), and sequential heterologous infection results in a pool of Ag-specific memory CD8 T cells with a phenotypic profile reflective of Tcm cells that are metabolically fit, proliferate robustly following re-infection, and provide protection against LCMV-clone 13 (34).