Fifty years of HIV: how close are we to a cure?

It's half a century since the first known HIV-related death and two patients appear to have been cured of the virus. What does this mean for the 37 million still living with it?

Nobody knew what killed Robert Rayford. The African American boy was just 15 years old when he presented at St Louis city hospital in late 1968, but the medical team drew a blank.

Unexplained swelling in Rayford's genitalia soon spread throughout his body. Chlamydia bacteria, usually localised at the point of entry, coursed through his bloodstream. A small purple lesion on the inside of his thigh signalled cancer, but of a form usually found in elderly Ashkenazi Jews and Italians, not teenage black boys who had never left Missouri.