"What was unthinkable just three years ago is now in sight: an AIDS-free generation"

Lifesaving drugs known as antiretrovirals that have brought millions of AIDS sufferers back from the brink also dramatically cut the risk that they will transmit the virus to their loved ones – by as much as 96 percent.

The landmark study, known as the HIV Prevention Trials Network 052 trial, proved that AIDS treatment was also a powerful form of prevention. Science magazine dubbed it the 2011 Breakthrough of the Year.

The findings – along with studies on the preventive benefits of circumcision and treating high-risk individuals before they are exposed to HIV – have been heralded as weapons that could finally break the back of the AIDS epidemic.