Materials and Methods: By flow cytometry, the amount of cytokine (interferon gamma—IFN- γ, interleukin 2—IL-2, tumor necrosis factor alpha—TNF-α) secreting T-cells were measured after 10 days of pre-sensitization and 6 h of re-stimulation with mixtures of pooled overlapping peptides from U54, staphylococcal enterotoxin B (SEB, positive control), or Actin (negative control) in healthy children and adolescents without any underlying immune disorder or infectious disease. This evidence concerns the gene IFNG and infectious disease.