Narrated by Richard Gere, this is the riveting story of the people and organizations leading the global hunt for the cure for AIDS. With approximately 100,000 people a week newly infected with HIV, and three million expected to die next year alone, finding a vaccine to stop the AIDS pandemic is one of the greatest challenges facing humanity. Yet 20 years after the pandemic began, large-scale human trials have been completed for only one vaccine candidate - and that candidate was widely considered a dismal failure. The program takes viewers from high-tech labs in America and Africa to Kenyan clinics where dying patients seek treatment and to Ugandan sugar cane plantations that are preparing for future large-scale trials. It also delves into the lives and bodies of those who seem to resist the invader naturally, people in whom HIV somehow, for reasons that remain tantalizingly elusive, does not lead to AIDS.

Encore March 30, 2006, 10:00 p.m. ET