Inclusion Criteria:  Cohort of exposed hospital workers  - Hospital caregiver or non-clinician agreeing to participate in the study defined as: Healthcare personnel (physician, nurse, orderly, physical therapist, midwives) who have worked for a minimum of 2 weeks since March 1, 2020 in a care unit dedicated to the management of patients confirmed or suspected of COVID-19 infection, in the participating centers: intensive care units, emergency rooms, COVID-19 units;  Staff (physician, technician) who have worked for a minimum of 2 weeks since March 1, 2020 in the AP-HM laboratories handling samples from patients confirmed or suspected of having COVID-19 infection Person affiliated to a social security system  Cohort of 'unexposed' hospital workers  Hospital care worker (physician, nurse, orderly) willing to participate in the study who has not worked since March 1, 2020 in an intensive care unit or emergency department or other department dedicated to the management of patients confirmed or suspected of having COVID-19 infection. Person affiliated with a social security system  Exclusion Criteria:  Hospital worker declining to participate If the hospital worker changes assignment after the first collection, he/she remains in the exposed cohort. Protected adult Person under legal guardianship or curatorship