Infection with the SARS-CoV-2 coronavirus (COVID-19) has recently been identified as a pandemic due to the speed and global scale of its transmission. In Auvergne-Rhône-Alpes region (AURA), the epidemic began in February 2020 and the number of infected people is still important. Between 15 and 20% of COVID-19 patients develop an acute respiratory distress syndrome (ARDS) leading to their hospitalization in intensive care. Their clinical progression can be rapidly harmful with the development of severe ARDS associated with an increased risk of death. Preliminary data on the immune response of COVID-19 patients describe the induction of a moderate inflammatory response and the occurrence of major progressive lymphopenia over time associated with potential immunosuppression. Up to 50% of secondary infections are reported in deceased COVID-19 patients. However, no prospective study has exhaustively described the kinetics of the immune response of COVID-19 patients in intensive care. The precise description of the immune response over time in adult patients with a proven infection with the SARS-CoV-2 virus and the study of the relation between this response and the increased risk of organ failure (severe ARDS), death or nosocomial infection will allow us to better understand the pathophysiology of the immune response induced by COVID-19 in order to (i) identify new therapeutic strategies targeting the host response in patients in intensive care (ii) to develop biological markers to stratify patients for future clinical trials evaluating these immunoadjuvant treatments in COVID-19.