Producing survey data during the pandemic. A history of the Sapris and Epicov projects

At the beginning of 2020, the first cases of Covid-19 were detected in France. Various actors sought to document the effects of the crisis. Among them, the National Institute of Health and Medical Research (Inserm) aimed to produce data on the living conditions and immune status of the population. This article, grounded in the sociology of quantification, examines the effects of the health crisis on data production process. We analyze Inserm's strategies for gathering data on the health situation. We show that the crisis led the institution to experiment with two data production strategies, despite the urgency and intensity of the work. The first strategy used existing resources - epidemiological cohorts - and resulted in the Sapris survey. The second targeted certain data properties - representativeness - and led to the Epicov survey, in partnership with official statistics services. Ultimately, the health crisis provided a unique situation of coexisting survey strategies in an emergency context.