Presence of SaRS-Cov-2 antibodies following exposure to Coronavirus Disease 2019 (COVID-19) and/or vaccination is a major indicator of immunization. Few data exit about serology response in nursing homes (NHs), i.e. in the most vulnerable population for developing severe forms of the disease.

Residents and health professionals in 9 nursing homes (NHs) with SaRS-Cov-2 antibodies detection after exposure (either COVID-19 or vaccine) All biological tests were performed in the frame of the standard care of residents and health professionals and all participants did not express opposition for using anonymously their data for the purpose of this academic analysis. In addition all Directors and Physicians of these NHs accepted to participate in this study

Inclusion Criteria:

For Residents:

• Living in one of the 9 Nursing Homes that participate in this study
• Having a SARS-COV-2 post vaccination serology.
• Having no objection for using the results of the serology for the purpose of this analysis

For Health Professionals:

• Working in one of the 9 Nursing Homes that participate in this study,
• Having a SARS-COV-2 post vaccination serology.
• Having no objection for using the results of the serology for the purpose of this analysis

Exclusion Criteria:

• None

Residents of the 9 Nursing Homes that participate in this study Health professionals working these Nursing Homes

The database can be used by other groups but only for academic purposes