The Major Areas of Interest (DIM) initiated by the Île-de-France region are a flagship scheme that aims to unify the laboratory networks located in Île-de-France by acting upon targeted accredited areas. In December 2016, the Île-de-France region accepted the financing of the 1HEALTH Major Area of Interest project, whose goal is to build a solid “One Health” infectiology network, unique in France and with European scope, in order to respond to public health challenges. One of its main goals is the development of new concepts in the areas of vaccinology, anti-infective therapy, diagnostics and the integration of social and economic considerations in health.