LONDON, March 23: British scientists are planning large-scale human trials of two new gels designed to prevent men and women from being infected with the virus that causes AIDS.

The gels, or microbicides, act like an invisible condom and could offer added protection against the virus that has infected 40 million people worldwide.

AIDS experts estimate that even a partially effective microbicide could prevent 2.5 million deaths from AIDS over three years. "We desperately need new methods to prevent HIV transmission in the face of rising prevalence of infection globally," said Professor Jonathan Weber, of Imperial College London, who is working on the project.

AIDS experts say microbicides will be most effective when used along with other prevention methods against AIDS. Microbicides could also protect against other sexually transmitted diseases.

"We need a product that women and men find culturally and personally acceptable, as well as free or at very low cost," Robin Gorna, of Britain's Department for International Development (DFID), told a news conference.

Sixty microbicide products are under development worldwide and 14 are already in clinical trials. The trials will enable researchers to see whether the products, which have proven effective in laboratory and animal studies, prevent infection in humans. -Reuters