Rinaldi S, de Armas L, Dominguez-Rodríguez S, et al. - In the present study, the researchers sought to describe the immune activation and immune checkpoint expression profiles of both CD4 and CD8 T cells along with the frequency and function of HIV-specific CD4 and CD8 T cells in a cohort of children and adolescents vertically infected with HIV. The authors discovered a T cell immune signature associated with viral reservoir size in a pediatric population, which is currently lacking in the field. Frequencies of PD-1+ and TIGIT+ CD4 T cells, as well as the frequency of HIV-specific CD4 T cells, were at the core of this immune signature, which could distinguish between people with low or high viral reservoir. This signature could be used to direct interventions toward relevant targets or as an endpoint for evaluating the efficacy of HIV remission therapies in pediatric populations.