The inclusion and exclusion criteria have become very restrictive, resulting in a very limited eligible population

At present, the offer of tests for the serological diagnosis of CoVID-19 (detection of IgG, IgM or IgA antibodies against CoV-2 SARS) is plethoric and is based on the use of a very large number of rapid diagnostic unit tests, a few dedicated high throughput automated systems or reagents on existing open systems. The offer will continue to expand in the coming months.

In order to meet the objectives mentioned by the Prime Minister, and confirmed in the HAS report of April 16, 2020 and in the opinion n°6 of the COVID-19 scientific council concerning the potential use of these serological tests at the end of the COVID-19 epidemic, the Virology laboratory wishes to validate the sensitivity and specificity of the tests it intends to use.

Inclusion Criteria:

The inclusion criteria in the retrospective "Negative/Potentially Interfering" group are as follows :

• Adult patient sampled prior to the onset of the COVID-19 epidemic (before January 2020)
• Patient presenting a coronavirus infection other than SARS-CoV-2, or other respiratory viral infections (influenza, metapneumovirus)
• Patients for whom a serum is kept in the biocollection declared under the number AC-2014-2293 and kept in the Institute of Clinical Biology, University Hospital of Rouen.

The criteria for inclusion in the "acute point infection" group are as follows:

• Patients screened by a positive RT-PCR for an SARS-CoV-2 infection
• Patients aged ≥ 18 years old
• Patients taken in charge in the emergency room / in a unit / in COVID resuscitation at the Rouen University Hospital.
• Patients having read and understood the briefing note
• Non-opposition to participation in the study

The criteria for inclusion in the "Sequential acute infection" group are as follows:

• Patients with positive RT-PCR for CoV-2-SARS infection
• Patients aged ≥ 18 years old
• Taken care of in a COVID unit at the Rouen University Hospital
• Having read and understood the briefing note and signed the informed consent form

The criteria for inclusion in the "Convalescent" group are as follows:

• Caregivers working at the UH of Rouen
• Screened by positive RT-PCR for SARS-CoV-2 infection,
• Healed for at least one month at the time of inclusion
• Having read and understood the briefing note and signed the informed consent form

Exclusion Criteria:

• Minor person
• Known Pregnancy
• Person deprived of liberty by an administrative or judicial decision or person placed under judicial protection / subtutorship or guardianship
• Person not affiliated with social security
• Person who does not understand and speak French