The emergence of the AIDS epidemic three decades ago represented an historic and unexpected development, upsetting the belief that the era of widespread infectious disease was coming to an end.

Since the beginning of the epidemic, almost 60 million people have been infected with HIV and 25 million people have died of HIV-related causes (UNAIDS and World Health Organization 2009). Yet, in that time an immense amount has been accomplished: scientific breakthroughs, unprecedented increases in global funding, and a new model for human rights and public health policy. Millions of lives have been saved.

At the end of 2010, five million people in sub-Saharan Africa had access to anti-retroviral treatment, whereas at the beginning of the millennium fewer than 100,000 had access (World Health Organization 2011).

The expansion of treatment has been one of several events that have recently changed the AIDS landscape. There have been positive research breakthroughs in demonstrating the effectiveness of male circumcision to prevent acquisition of HIV in men, and of treatment as prevention in serodiscordant couples. On the political side, the June 2011 United Nations Security Council Resolution on HIV/AIDS and General Assembly Political Declaration on HIV/AIDS reflect a promising level of renewed political engagement, as well as a changed strategy to focus on the populations that are at highest risk of HIV.