Immune Response and Risk of Serious Infection to SARS-Cov2

To date, nearly 2 million people, including at least 100,000 in France, have been infected with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). This infection is very heterogeneous in nature, ranging from asymptomatic forms to acute respiratory distress syndrome patterns in 6.1% of cases, leading to an estimated overall mortality of 5.2%. Apart from age, few risk factors for a pejorative evolution have been identified: arterial hypertension, diabetes, cardiovascular history, obesity and chronic respiratory pathology in particular. The median incubation period is 5 days and the median time between the appearance of the first symptoms and the onset of hypoxia requiring admission to intensive care is 7 to 12 days. The mechanisms involved in the occurrence of these secondary worsening patterns are unclear. One hypothesis is that it is related to an inappropriate inflammatory response rather than a direct cytopathic effect of the virus. The objective of this study is to measure the intensity of the T lymphocyte response in patients hospitalized for Cov2 SARS infection in order to determine whether the intensity of the response is associated with worsening of symptoms.