The main objective of this study is to describe the humoral and cellular response to BNT162b2 vaccination in people over age 75 institutionalized in the long-term care units of the Paris Public Hospitals (APHP)

This is an interventional study with minimal risk and constraints, multicenter with biological collection. Two populations are studied: patients and members of care staff.

The following data will be collected:

• For patients and staff: age, gender, existence of Coronavirus Disease 2019 (COVID-19) infection and whether or not it is symptomatic and date of first positive RT-PCR test, medical history
• For patients: nutritional status (loss of appetite, weight loss, body mass index, albuminemia)

Vaccination antibodies are measured using 3 blood sample:

The first carried out before the anti-Coronavirus Disease 2019 (COVID-19) vaccination; the second on D21 (shortly before the vaccination booster injection) and the third on D50-54.

In addition, during the first sample, assays will be carried out informing us of your nutritional and inflammatory status.

Inclusion Criteria for patients:

• Person aged 75 and over,
• Hospitalized in a long-term care unit participating in the study,
• Having agreed to be vaccinated with the BNT162b2 vaccine as part of the phase 1 vaccination campaign defined by the health authorities,
• Not having received any other vaccination or corticosteroid treatment during the 3 weeks preceding the start of the study,
• Having given their written consent to participate in the study, or having not expressed their opposition to participating and whose legal guardian has given their consent.

Inclusion Criteria for younger adults (priority care staff):

• Staff who have agreed to be vaccinated with the BNT162b2 vaccine as part of the phase 1 vaccination campaign defined by the health authorities,
• Not having received any other vaccination or corticosteroid treatment during the 3 weeks preceding the start of the study,
• Having given their written consent to participate in the study.