Researchers say a medicinal gel being tested in South Africa has almost halved the risk of women being infected with HIV when routinely use before sex. The World Health Organization and the UN AIDS agency called the results groundbreaking. Here's Bethany Bell.

Researchers in South Africa say that a gel they've tested among 900 women cut the risk of HIV infection by 39%. Those who used the gel regularly had their risk of infection lowered by 44%. But the gel's effectiveness appear to decline after 18 months. The gel which contains an AIDS drug is still at an experimental stage.