New Way To Protect Women from HIV
Natural Vaginal Flora Engineered for HIV Prevention
Sept. 10, 2003 -- A woman's normal-occurring vaginal bacteria give her natural protection from infection. Now researchers say these friendly bacteria can be engineered to protect against the HIV virus.
It's one of those why-didn't-anyone-think-of-this-before ideas. Helpful bacteria called lactobacilli live in the mucous membranes that line a woman's vagina. They produce acids that kill germs and prevent infection. Obviously, some germs get through. And the most deadly of these is HIV.
Now Stanford researcher Peter P. Lee, MD, and colleagues have engineered these bacteria to make a trap for the AIDS virus. The bacteria produce a fake version of the docking site HIV uses to grab hold of the cells it wants to infect. It works like flypaper, trapping HIV and holding it while the bacteria's natural acids kill the virus.
"Essentially all mucous membranes of the body are colonized with normal, healthy bacteria," said Lee in a news release. "So why not try somehow to harness that and take advantage of these healthy bacteria to either block or inactivate viruses before they can get in?"
It works in the test tube. Monkey tests are ongoing; so far it seems safe. But even if these tests are a big success, years of human safety and efficacy testing will be needed.
Wanted: Woman-Controlled AIDS Prevention
AIDS is a preventable disease. You can't get HIV from sex if you don't have sex. And if you do have sex, a latex condom offers pretty darn good protection.
But in most of the world, women can't choose either method. They are not free to refuse to have sex with their husband, even if they know he's been sleeping with other, HIV-infected women. And they are not free to use a condom unless their husband agrees.
And when economic circumstances force a woman to turn to prostitution, it becomes an even riskier situation.
That's why there's such a worldwide need for a discreet, woman-controlled means of preventing HIV. But the female condom isn't discreet. And sperm-killing microbicides often irritate the vagina, paradoxically making it easier for HIV and other germs to cause infection.
Lee says that engineered bacteria could be put into a suppository that dissolves in the vagina. A woman could use it in privacy, once or twice a week. If effective -- and affordable -- such a product would have a huge, worldwide impact on the AIDS epidemic.
And there's no reason why this idea can't be used to protect women against other sexually transmitted diseases, too.
The study appears in this week's online edition of the Proceedings of the National Academy of Sciences.