The adaptive and innate host immune responses to sepsis. Patients in the early phases of sepsis present with fever, shock, and multiorgan failure, as well as evidence of a hyperinflammatory innate immune response. Patients surviving this phase may recover or progress to a later phase of sepsis resulting in a more immunosuppressed profile, characterized by functional deficits of the immune system and by superinfection and poor outcome. Adapted and reprinted by permission from Macmillan Publishers Ltd: Hotchkiss et al.,¹⁶  Nature Review Immunology, copyright 2013.