Acknowledgements
We thank (i) Drs. Vincent Foulongue and Monsef Benkirane (Montpellier) for providing the SARS-CoV-2/CHU Montpellier/France strain, and (ii) Drs. Olivier Terrier, Andres Pizzorno and Manuel Rosa-Calatrava (CIRI, Centre International de Recherche en Infectiologie, Team VirPath, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Lyon) for providing the Gisaid UK (B.1.1.7): EPI_ISL_900512 strain, referred to as hCoV-19/France/ARA-SC2118/2020.
The authors would also like to thank Anna Bedbrook, Fabienne Portejoie (MACVIA France), and Eva Pons (Master Métiers de l’Enseignement, de l’Education et de la Formation; éducation nationale française, Lyon) for their editorial assistance, Joy Martin, Isabelle Bussereau, and Marie-Suzanne Léglise, Secours Infirmiers (Department of Geriatrics, Montpellier University Hospital), Véronique Vera and Florence Biblocque (admission office, Montpellier University Hospital) for material support, Xavier Basagaña for his methodological support, as well as the residents and staff members of the nursing homes involved in the study. None of these contributors received any compensation for their help in carrying out the study.