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

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.