Two doctors at the epicentre of the AIDS crisis - Glenda Gray and Wafaa El-Sadr - have worked tirelessly to care for those affected by the virus, to combat its spread, and to get the drugs to those who need it.

Glenda Gray is a South African paediatrician and world-renowned scientist who currently directs the HIV Vaccine Trials study, which is the largest of its kind ever conducted in South Africa. Thanks in part to her work on mother-to-child transmission, the number of babies born with HIV has dropped dramatically from 600,000 a year to 150,000. Glenda herself grew up under Apartheid in a family of activists, and carried on her fight for social justice into medical school and beyond.

Wafaa El-Sadr is director of ICAP based at Columbia University in New York. Born in Egypt to a family of physicians, Wafaa was working as a young doctor in Harlem, when the first AIDS cases began to appear in the 1980s. She didn't know she was witnessing the start of an epidemic that was to sweep across the globe. Wafaa helped develop a treatment programme that is now used as a model around the world.

Image: (L) Glenda Gray (credit: JP Crouch Photography) and (R) Wafaa El-Sadr (credit: Michael Dames)