CD19 and vaginal inflammation: As vaginal inflammation has been associated with increased immune cell infiltration, we used multiparameter flow cytometry to phenotype endocervical immune cells collected from study participants to detect immune cell lineages (CD4+ T cells, CD8+ T cells, CD19+ B cells, CD56+ Natural Killer (NK) cells, CD14+ antigen-presenting cells (APCs), and CD15+CD16+CD49d- neutrophils) (Fig. 2A, Supplemental Figure 1).