TNF and acute respiratory distress syndrome: In general, these immunological modifications contribute to the poor prognosis in the elderly since severe cases have been associated with elevated levels of inflammatory cytokines such as IL6, TNF-α, and interferon-γ (IFN-γ), as well as lower lymphocyte counts (specifically CD8+ and CD4+) [15], mainly attributable to an inadequate immune response, proinflammatory basal state and consequent inability to overcome the inflammatory process associated with viral pneumonia and tissue injury leading to acute respiratory distress syndrome (ARDS) [18].