The goal of this second day was to revitalize health surveillance practices in the Brittany region and to strengthen and expand networks among various institutions and stakeholders, particularly with regard to responding to alerts. The day was structured around three main themes: 1. vaccinations as a means of preventing potentially serious diseases, 2. the implementation of surveillance systems for alerts and management, 3. feedback on health alerts that led to investigations and the implementation of specific public health actions. It was open to all professionals involved in health monitoring and alert systems in Brittany, both in the field of generating and processing health and environmental signals, and in the field of managing alert situations (private and hospital-based physicians, medical testing laboratories, PMI, school health, occupational health, environmental health, CClin and Arlin, medical-social institutions, associations, ARS staff...). (R.A.)