Evolution of Protective Immunization Against COVID-19 Among Hospital Workers in Health Care Facilities

Evolution of Protective Immunization Against SARS-CoV-2 Among Hospital Workers in Health Care Facilities

To measure the immunization rate (seroneutralization) in a population of exposed hospital workers (nursing staff assigned to dedicated COVID-19 care units, laboratory staff handling COVID-19 samples).

Current studies on seroconversion and the time course of immunity following exposure to SARS-CoV-2 do not document: i) Seroconversion in populations in repeated and frequent contact with patients; ii) The temporal dynamics of seroconversion at medium term. These two elements are however fundamental in the comprehension and management of this epidemic or of its potential resurgence in the following months and years.

Objective: To measure the immunization rate (seroneutralization) in a population of exposed hospital workers (nursing staff assigned to dedicated COVID-19 care units, laboratory staff handling COVID-19 samples).

Secondary objectives:

1. Determine the kinetics of the protective response over 12 months (4 times).
2. Compare immunization profiles according to: gender, age, lockdown, blood type, occupational class, exposure, asymptomatic/symptomatic.
3. Compare immunization kinetics between exposed and low-exposure hospital workers.
4. To determine the characteristics of the ELISA test in comparison with the reference test (seroneutralization).

Perspectives

• To provide a reliable, affordable and faster serological test.
• Understanding of the natural evolution of seroprotection in a population over time.
• Sensitization to plasma donation for seropositive patients.

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