EpiCov is a population-based cohort which aims to provide national and regional estimates of seroprevalence of SARS-CoV-2 infection and analyse relations between living conditions and the dynamics of the epidemic in France. The study population is a random sample of individuals aged 15 years and older, excluding people living in residences for the elderly and living in jail. The participants are recruited from the French national tax register and is representative of the population living in France. Home self-samples on Dried Blood Spots (DBS) for IgG and neutralizing antibodies detection were offered to a random national sub-sample of 12,114 in the 1st round of the EPICOV survey (May 2020) and to all respondents in the 2nd round (November 2020), including also serological testing for all members (≥ 6 years old) of household for 20% of index participants. A third round was perfomed in June-July 2021, without serological measurements. Overall, 134,391 participants have been enrolled in first-round (May 2020). Among them, 107 759 participated to the second round (November 2020) and 85 074 in third round (June 2021). The next wave is expected in March-april 2022.

Inclusion Criteria:

• individuals aged 15 years or older
• living on January 1, 2020, in mainland France or one of three overseas departments (Martinique, Guadeloupe and Réunion Island).

Exclusion Criteria:

• individuals living in prisons at the time of the study
• people living in residential institutions for dependent elderly persons, as caregivers were not available during the epidemic period to help them with internet access or phone calls.

Population-based sample based on a national random probability sample from the administrative sample frame: all individuals aged 15 years or older on January 1, 2020, living in mainland France or one of three overseas departments (Martinique, Guadeloupe and Réunion Island). Due to the poor quality of the sampling frame, poor internet access and the use of multiple languages, two other overseas departments, French Guiana and Mayotte, were excluded from the study.

The EpiCov data is available for research purpose, 9 months after overall completion of one round. Access to anonymized individual data may be available before the planned period of open access : specific project has to be presented to the EpiCov exploitation committee : if accepted, it needs approval of ethics and reglementary Committee for researchers who meet the criteria for access to data.

The first round, and will be available by March 2022 concerning the second round for research purpose on CASD (https://www.casd.eu/), after submission to approval of French Ethics and Regulatory Committee procedure (Comité du Secret Statistique, CESREES and CNIL).

The first round is currently available and the second rond will be available by March 2022

Access for research purpose of first and second round on CASD (https://www.casd.eu/) is given after submission to approval of French Ethics and Regulatory Committee procedure (Comité du Secret Statistique, CESREES and CNIL).

Access to data for subsequent rounds may be available before the planned period of open access : specific project has to be presented to the EpiCov exploitation committee : if accepted, it needs approval of ethics and reglementary Committee for researchers who meet the criteria for access to data.