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

Study Overview
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Brief Summary
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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).

Detailed Description
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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: Determine the kinetics of the protective response over 12 months (4 times). Compare immunization profiles according to: gender, age, lockdown, blood type, occupational class, exposure, asymptomatic/symptomatic. Compare immunization kinetics between exposed and low-exposure hospital workers. 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.

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

Conditions
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Covid19

Intervention / Treatment
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* Other: Blood sample


Participation Criteria
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Eligibility Criteria
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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
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Screening
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exposed hospital staff<br>Hospital health care or non-health care staff willing to participate in the study: Healthcare personnel (physician, nurse, caregiver) 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, radiology, 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. | Other: Blood sample<br>* Seroneutralization and Elisa tests<br>|
| Other: 'Non-exposed' hospital workers<br>Hospital health care worker (physician, nurse, caregiver) 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. | Other: Blood sample<br>* Seroneutralization and Elisa tests<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To establish the level of immunization (seroprevalence) to COVID-19 as determined by the seroneutralization test in a population of exposed hospital workers | Positive seroneutralization test result: the threshold of positivity is set at 40, i.e. any serum with a seroneutralizing value greater than or equal to 40 will be considered positive. | 4, 8 and 12 months follow-up visits after the initial visit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Kinetics of the protective antibody immune response (protective immunization against SARS-CoV-2 COVID-19) in a population of exposed hospital workers over a 12-month period. | The kinetics of seroprevalence will be defined by the results of the seroneutralization test at 4 time-points (4, 8 and 12 month follow-up visits after the initial visit). | 4, 8 and 12 months follow-up visits after the initial visit | 
| Compare immunization profiles | Combine multiple measurement in order to compare immunization profiles (symptomatic status,individual characteristics, i.e, gender, age range, condition of lockdown, blood type; professional characteristics and possible clinical signs. | 12 months after the initial visit | 
| Compare the seroprevalence of SARS-CoV-2 and the kinetics of immunization between two groups (exposed hospital workers and a less exposed hospital workers). | Compare between groups the results of the seroneutralization test over time. | 4, 8 and 12 months follow-up visits after the initial visit | 
| Identify the technical (sensitivity and specificity) and predictive (positive and negative predictive values) characteristics of the ELISA test evaluated in comparison with the reference test (serum neutralization) in the population of interest. | ELISA's test positivity will be defined with reference to the manufacturer's recommendations. For a ratio OD of the tested sample / kit control: <0.9: negative test Between 0.9 and 1.1: unspecified test >1.1: positive test The result will be processed under two modalities: negative/indeterminate/positive and quantitative | 12 months | 
| Record COVID-19 seroprevalences established by ELISA at different time points: inclusion, 4 months, 8 months, and 12 months after inclusion. | The technical and predictive characteristics of the ELISA test (sensitivity, specificity, positive predictive value and negative predictive value) are documented by reference to the serum neutralisation test. | 4, 8 and 12 months follow-up visits after the initial visit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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serology, healthcare workers