Validating an ELISpot for Early Detection of an Active Immune Response Against COVID-19 (EliSpot)

The RT-PCR on rhino-pharynge sampling highlights the genetic material of the virus and indicates that a subject is infected with SARS-CoV-2. This test can be in about 30% of false negative cases, it does not allow to date the infection, nor to predict the asymptomatic, mild, moderate or severe evolution of the disease. In terms of public health, we need 1/ to better understand the chronology of the immune response to the virus in the general population and in contacts of index cases; 2/ To know which characteristics of the immune response are protective of future reinfections. Finally, in symptomatic subjects, we need biomarkers that predict the evolutionary mode of the disease (moderate vs. severe form).

COVID-19 patients will be selected in the 4 participating centres Contact subjects and healthy volunteers will be selected only in the coordinating centre (Centre Hospitalier Universitaire de Nice)

Exposure to SARS-Cov2 but no symptoms (patient's family, medical staff) and General population (volunteers not exposed to SARS-Cov2)

Proportion of subjects with IgA-specific cells of SARS-CoV-2's Spike 1 protein at inclusion and 7 +/-2 days later

Inclusion Criteria: age ≥ 18 years, patients with confirmed SARS-Cov2 infection (RT PCR positive) or patients suspected (evocative chest scanner) OR patients exposure to SARS-CoV2 but no symptoms (patient's family, caregivers) OR patients Non exposure to SARS-Cov2 volunteer subjects (general population) Exclusion Criteria: pregnant or breastfeeding female