Increased numbers of CD4+ and CD8+ naïve (CD4+CD44lowCD62Lhigh and CD8+CD44lowCD62Lhigh, respectively) as well as CD4+ and CD8+ effector (CD4+CD44highCD62Llow and CD8+CD44highCD62Llow) T cells were detected at week 2 after infection. This evidence concerns the gene CD4 and infection.