Practical prevention of vaginal and rectal transmission of HIV by adaptingthe oral defense: Use of commercial lubricants

HIV is transmitted to 6.4 million human beings per year and the majority of these transmissions are sexual. Condoms are highly effective and are recom mended as the primary preventive. However, the fact that there are millions of sexual transmissions each year indicates that many people do not use co ndoms and that additional preventives are needed. The mechanisms of natural prevention of oral transmission by saliva may be adaptable to the suscepti ble vagina and rectum. The objective of our study was to reduce the sexual transmission of HIV by mimicking saliva's targeting of the transmitting inf ected leukocytes and any cell-free HIV in seminal fluid. The previously rec ommended anti-HIV topical microbicide, nonoxynol-9, has not prevented HIV t ransmission in humans, probably because it causes mucosal irritation and at tracts CD4+ cells. To identify effective preparations that are nonirritatin g, we studied the anti-HIV activity of commercially available, over-the-cou nter (OTC) lubricants and vaginal preparations that are judged safest by th e U.S. Food and Drug Administration (FDA), and are nonirritating. The effec t of OTC preparations on both the production of HIV by infected leukocytes and cell-free HIV suspended in seminal fluid was measured under simulated i n vivo conditions. We surveyed 22 OTC vaginal preparations and excluded tho se with low inhibitory activity and those that were inhibitory but likely t o be irritating. Three included preparations are highly active against both HIV-infected leukocytes suspended in seminal fluid and active against cell -free HIV, under in vitro conditions that simulate in vivo conditions. Sinc e the preparations identified here as anti-HIV substances have the advantag es of being widely available, inexpensive, acceptable, in the safest U.S. F DA category, and may be used by recipient women or men, they should be test ed in clinical trials to help prevent sexual transmission of HIV.