CD4 and infective vaginitis: Second, the small sample size was insufficient to examine the effects of multiple covariates that can affect T cell phenotype in the female genital tract or even cellular yield, including vaginal infections, the presence of semen, mucosal trauma, endogenous or exogenous hormones, and the vaginal microenvironment including the vaginal microbiome which can impact HIV risk, in part, by altering the phenotype of FGT CD4 T cells [46].