The COVID-19 testing strategy remains essential, with systematic testing (rapid antigen tests) to account for asymptomatic cases and adapt to the high density of people living in extremely precarious conditions—often housed in group shelters—as well as to the dynamics of the epidemic amid strain on hospitals and housing resources. During the pandemic, the basic needs (water, food, hygiene) of this population—as well as their needs regarding access to healthcare, digital services, education, and improved mental health care—are even more pressing. The strengthening of ties between the social and health sectors, particularly through mobile teams, must be consolidated and sustained, as in crisis situations, referring these populations to standard public services may be insufficient to ensure adequate care. Accommodation and isolation protocols raise ethical and legal questions, as highlighted by the testimonies of those involved. Security concerns can hinder social work and underscore the need to maintain this “outreach” approach in crisis situations. Supporting professionals, particularly in the social sector, over time with the appropriate tools—by valuing people’s ability to adapt as best they can and developing appropriate, co-designed interventions that incorporate participatory aspects—must be a priority for Santé publique France. The implementation of the vaccination program also incorporates this approach of knowledge sharing and mobilization. It takes into account risks and needs and adapts to the specific contexts of these populations by working closely with the stakeholders who serve them and by drawing on a better understanding of attitudes and behaviors.