inclusion criteria: * individual (male and female) aged 18 or over. * healthcare worker (medical or non-medical) from hospitals in direct contact with covid-19 patients. * participants must give their written consent before any trial procedure. * participants covered by social security regimen (excepting ame). * healthy according to the opinion of the investigator.

inclusion criteria: * individual (male and female) aged 18 or over. * healthcare worker (medical or non-medical) from hospitals in direct contact with covid-19 patients. * participants must give their written consent before any trial procedure. * participants covered by social security regimen (excepting ame). * healthy according to the opinion of the investigator.

inclusion criteria: - individual (male and female) aged 18 or over. - healthcare worker (medical or non-medical) from hospitals in direct contact with covid-19 patients. - participants must give their written consent before any trial procedure. - participants covered by social security regimen (excepting ame). - healthy according to the opinion of the investigator.

inclusion criteria: - individual (male and female) aged 18 or over. - healthcare worker (medical or non-medical) from hospitals in direct contact with covid-19 patients. - participants must give their written consent before any trial procedure. - participants covered by social security regimen (excepting ame). - healthy according to the opinion of the investigator.