The vulnerability of HIV-infected patients with tuberculosis is not solely due to socioeconomic hardship. Other factors, such as administrative, emotional, psychological, linguistic, or cultural insecurity, play a role that is often underestimated. Migrants, who are particularly affected by this co-infection, as well as other populations for whom health is often no longer a priority, suffer greatly from it. This vulnerability, exacerbated for undocumented migrants by the fear of deportation and by highly restrictive administrative practices that do not always comply with the law, contributes to keeping patients away from care, resulting in delayed medical intervention at very advanced stages of immune deficiency and/or tuberculosis. Responses to these challenges must be multifaceted and should rely on the necessary collaboration between social and healthcare professionals, institutions, and community organizations. The first step is for professionals to recognize the reality of these challenges in all their forms, with the ability to listen and the availability of time being essential. Furthermore, the establishment of support structures such as mediation—particularly cultural mediation—and multidisciplinary teamwork is a path forward, as is the creation of “outreach” teams to reach out to those who are afraid or no longer have the strength to go to the hospital. Beyond the individual challenge, there is a genuine public health problem, as all the factors are in place for the spread of multidrug-resistant tuberculosis strains. (R.A.)