Fig. 2: Potential mechanisms of action for microbicide compounds. Balzarini J , and Van Damme L CMAJ 2005;172:461-464 ©2005 by Canadian Medical Association Fig. 2: Potential mechanisms of action for microbicide compounds. Microbicides that act as a lubricant coat the epithelial surface, which might reduce the risk of trauma and provide a physical barrier against viral infection. Prevention (or treatment) of other STDs can reduce the risk of HIV transmission by reducing the risk of epithelial inflammation and ulceration. In the vagina, maintaining the normal flora, and therefore maintaining the vaginal pH at virucidal levels (pH less than 4.5), could also reduce the risk of transmission. Once the virus has crossed the epithelial barrier, potential microbicidal strategies include targeting HIV uptake by dendritic cells, targeting HIV adsorption and fusion, and targeting reverse transcriptase and integration into the host cell genome. Reproduced, with permission, from Shattock RJ, Moore JP. Inhibiting sexual transmission of HIV-1 infection. Nature Rev Microbiol 2003;1:25-34.