Here, we describe a comprehensive study in which the development of EBV-specific CD4+ and CD8+ T cells, as well as their magnitude and polyfunctionality were monitored from primary infection to long-term persistence in two cohorts of children with infectious mononucleosis (IM) and asymptomatic (AS) primary EBV infection, respectively. Here, CD8A is linked to Epstein-Barr virus infection.