Understanding the mechanisms of HIV transmission to women will be crucial to the
development of effective strategies to curb this epidemic. Current data suggest that HIV has
at least two routes to penetrate the vaginal epithelium and reach lymphoid tissues, trans-
epithelial migration of infected Langerhans cells or virus penetration into the lamina propria
through loss of epithelial integrity resulting in direct infection of lymphocytes, dendritic cells
and macrophages.