CD4 and infection: Virus-dependent decreases in peripheral blood CD4 + T cell counts were small but statistically significant at 6 months post-infection, prior to cART initiation (544 ± 129 × 103/μL compared to 768 ± 122 × 103/μL pre-infection, p = 0.034), and normalized after cART treatment (Fig. 1c).