During persistent inflammation in chronic viral infections, CD8 T cells are thought to become “exhausted”, a term signifying loss of their normal cytotoxic function. However, recent work from our lab and others has shown that some CD8 T cells in chronic viral infection do not become “exhausted” and instead retain their cytotoxic function. We are currently investigating what factors allow CD8 T cells to maintain their cytotoxic capacity, how CD4 T cells are involved in generating or regulating these factors, and how to leverage these factors to improve control over chronic viral infections.