TNF and lymphopenia: Severe EVD pathogenesis in primates bears many of the hallmarks of sepsis and is frequently described as having two distinct phases: (1) an initial pro-inflammatory phase characterized by widespread activation of cytokines/chemokines like TNF-α and IL-1β, and (2) a disrupted anti-inflammatory response that can limit successful lymphocyte activation and function, and which is distinguished by dramatic lymphopenia [6].