Study of SARS-CoV2 Virus (COVID-19) Seroprevalence in the Population of Creil Air Force Base (BA110)

Study Overview
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Brief Summary
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In mid-February 2020, within the Oise (France) cluster, a case of COVID-19 disease caused by a SARS-CoV2 infection was described among the personnel of the Creail Air Force Base (BA110). This resulted in the beginning of an epidemic controlled by epidemiological measures. One month later, containment measures were taken at the national level, measures that also applied to BA110 personnel. These personnel, exposed to both the initial phase of the epidemic and national protection measures, represent an extremely interesting population for understanding the epidemiological dynamics of the virus, particularly at a time when France is lifting the containment measures. It becomes extremely important to understand the levers of viral spread in order to adjust the health measures to be maintained as best as possible. The main objective of this study is to determine the extent of virus diffusion in this highly circulating population, as evidenced by several identified cases of COVID-19.

Official Title
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Study of SARS-CoV2 Virus (COVID-19) Seroprevalence in the Population of Creil Air Force Base (BA110)

Conditions
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Sars-CoV2

Intervention / Treatment
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* Diagnostic Test: Anti-SARS-CoV2 Serology
* Behavioral: Questionnaire
* Diagnostic Test: Anti-SARS-CoV2 serological controls and serum neutralization


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Active military or civilian defence personnel working on the Creil Air Force Base (BA110) during the period of interest (from February 1st 2020 to the end of the study) Exclusion Criteria: Contraindication to blood sampling Pregnant, parturient, breastfeeding woman

Ages Eligible for Study
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Minimum Age: 18 Years

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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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: Anti-SARS-CoV2 Serology|The anti-SARS-CoV2 serological status will be measured on a blood sample collected at Day 0.|
|Behavioral: Questionnaire|Epidemiological data will be collected in a questionnaire that will be filled by participants at Day 0 (Visit 1), after 3 months (Visit 2) and after 9 months (Visit 3). The questionnaire includes: medical data (height, weight, smoking, history of intense stress); socio-demographic data (age, gender, civil/military status, function/occupation, rank category, army, family status/home composition, housing conditions, etc.); clinical data : history of symptoms suggestive of COVID-19 in the last 3 months, current symptoms suggestive of COVID-19; use of care, hospitalization, work stoppage in the last 3 months; contact with people who are symptomatic or proven COVID-19.|
|Diagnostic Test: Anti-SARS-CoV2 serological controls and serum neutralization|Serological controls and a serum neutralization test will be performed on blood samples collected 3 months (Visit 2) and 9 months (Visit 3) after Day 0, respectively.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion anti-SARS-CoV2 seropositive | The percentage of the study population with positive serological status will be determined. ELISA serology test will be used to detect anti-SARS-CoV2 antibodies (IgG and IgM) at Day 0 | Day 0 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of asymptomatic anti-SARS-CoV2 seropositive participants | Among anti-SARS-CoV2 seropositive participants, the percentage of asymptomatic participants will be determined. COVID-19 symptoms will be measured using a questionnaire. | Day 0 | 
| Agreement between the anti-SARS-CoV2 serological results obtained using two different techniques (detecting the presence of different antibodies) | The serological results obtained using the reference ELISA test results (detecting the presence of IgG and IgM antobodies) and using a second ELISA test detecting the presence of antibodies specifically directed against the Receptor Binding Domain and the Spike protein trimer of SARS-CoV2 virus will be compared. | Day 0 | 
| Proportion of serum neutralization positive | Among anti-SARS-CoV2 seropositive participants, the percentage of participants with a positive response to serum neutralization will be determined. | Day 0 | 
| Change of antibody level over time | The evolution of the antibody level over time will be determined using repeated serodiagnoses at 3 and 9 months. | 3 months and 9 months after Day 0 |