We were also able to confirm the observations made for HLA DR expression in Tfh cells (p = 0.0195; dRM = −0.897, with a confidence interval of −2.172 to −0.233) and PD-1 expression in activated HLA DR+ CD4 T-cells (p = 0.0039; dRM = −1.714; 95% confidence interval [CI] = −3.815 to −1.655), both increased at infection. Here, CD4 is linked to infection.