Acknowledgements
The authors warmly thank all the volunteers of the Constances, E3N-E4N and NutriNet-Santé cohorts for their continuous participation in the study and for participating in the SAPRIS-SERO project. We thank the CEPH-Biobank staff for their adaptability and the quality of their work. In the virology department, we thank Dr Nadège Brisbarre and the technical staff for impeccable management of samples and serological assays.