https://www.selleckchem.com/products/verubecestat.html With a long experience in evaluating public health measures in the fields of HIV and drug addiction at national level, the Evaluation and Expertise in Public Health sector (CEESAN, Unisanté, Switzerland) has also been monitoring the situation in the canton of Vaud for more than twenty years. In this article, we present two instruments developed for epidemiological monitoring purposes the « Pointage annuel du profil des usager·ère·s des structures à bas-seuil d'accès » (PAPU, annual measure of users of low-threshold facilities' profile) and the online platform for opioid agonist treatments. The data collected through these two instruments provide information on the main characteristics of precarious drug users in the canton and help to guide public policy in this field.Physicians, pharmacists and caregivers, as well as public health officials and citizens, must sort through the enormous amount of information circulating about the pandemic. This crisis is accompanied by a real « infodemic » via multiple media, digital and otherwise. Is circulating a mixture of reliable information but also of misinformation, fed by the obscurantism jeopardizing the implementation of interventions such as vaccination or mask-wearing. To address this infodemic, evidence-based and data-driven public health should be strengthened. Debuting rumors - « see something, say something » - and promoting credible information limit misinformation. Strengthening people's knowledge in population health science would also help.Public health surveillance is the systematic and ongoing collection, analysis and interpretation of data to produce information useful for decision-making. With the development of data science, surveillance methods are evolving through access to big data. More data does not automatically mean more information. For example, the massive amounts of data on Covid-19 was not easily transformed in useful information for decision-