HIV vaccines are in their infancy, and effective microbicides to prevent sexual transmission of HIV still don’t exist. Women, making up nearly half of the world’s 33 million HIV cases, are especially in need of protection. Here’s a new possible way for women to protect themselves before sex: an applicator filled with specially formulated fatty particles called liposomes.
The tiny spheres measure 4 microns in diameter, not visible without a microscope, and consist of a double outer layer of lipids (fats) and hollow centers. They’re relatively easy and cheap to engineer, and thus present a viable option for developing countries, where the cost of anti-HIV drugs, while falling, still bars access for most people.