Science has brought the world to the point where the end of AIDS – though not necessarily HIV – is in sight, according to Secretary of State Hillary Clinton.

And, she added, "It is science that will allow us to finish this job."

The job, she has famously said, is to create an "AIDS-free generation" – something that once seemed like a pipe dream and now, after more than 30 years, seems increasingly possible.

In advance of World AIDS Day, Clinton outlined a five-point "blueprint" that she said will guide the President's Emergency Plan for AIDS Relief, or PEPFAR, in the next few years.

Central to the plan, Clinton said, is an emphasis on evidence and science.

"As a scientist, nothing could be more pleasing to me," commented Myron Cohen, MD, of the University of North Carolina in Chapel Hill.

Cohen, one of the leaders in recent research that has emphasized the role of treatment in slowing the pandemic, told MedPage Today the blueprint amounts to "doubling down" on what PEPFAR has been doing for the past four years.

It is, he said, "a commitment to what has been evolving."

PEPFAR is the main U.S. weapon globally against the HIV/AIDS pandemic, with outlays of more than $6.6 billion in fiscal 2012 for treatment and prevention of HIV.

It is also, arguably, the most successful U.S. foreign policy initiative in decades.

The new blueprint for U.S. action comes as some of those involved in the global public health efforts are hailing recent progress, including lower rates of infections in newborn children and increasing numbers of people on treatment.

Others, however, worry that progress is already too slow to reach Clinton's goal of ending AIDS, noting that there were still 2.5 million new HIV infections in 2011, only slightly lower than a year earlier.

Clinton said the "tipping point" will come when the number of people starting treatment every year is greater than the number acquiring the virus. After that point, the number of HIV-positive people progressing to full-blown AIDS would begin to dwindle.

"We don't know how long it will take to do this everywhere," she said, "but we know that we can do it."

Michel Sidibe, executive director of the Joint United Nations Programme on HIV/AIDS (UNAIDS), said that the Clinton blueprint "shows how the U.S. will support countries to start the endgame" against the pandemic.

It is "timely, topical, and catalytic," he commented after Clinton spoke.

The blueprint commits the U.S. to rapidly scale up treatment and prevention programs. Clinton said new figures now show that in 2012, the program directly supported antiretroviral therapy for more than 5.1 million people – twice the number who got therapy thanks to PEPFAR in 2008.

Clinton noted that the blueprint also says that PEPFAR money will increasingly "go where the virus is" – marginalized groups, such as sex workers, injection drug users, and men who have sex with men.

"When discrimination, stigma, and other factors drive these groups into the shadows, the epidemic becomes that much harder to fight," she said.

Clinton didn't promise any more money for the program, but she said PEPFAR will use what money it has as effectively as possible – switching to generic drugs in its treatment programs, for instance.

And, she said, the program will increasingly focus on ways of preventing HIV among girls and women, who, often because of inequality and violence, are at higher risk than men of catching the virus.

Interestingly, while the pandemic is mainly heterosexual in most parts of the world, in the U.S. it remains very largely confined to gay and bisexual men, and mainly in big cities, according to new figures released by the CDC.

In the Nov. 30 issue of Morbidity and Mortality Weekly Report, the CDC reported that geographic analysis of new infections in 2010 showed that male-male sex was the main method the HIV transmission:

In 103 so-called metropolitan statistical areas – regions with at least 500,000 people – male-male sex accounted for 62.1% of all new infections

In 263 smaller metropolitan areas – with between 50,000 and 499,999 people – male-male sex accounted for 56.1% of new HIV diagnoses.

And in 198 areas with fewer than 50,000 people, such contact accounted for 53.7% of all new infections.

But, the CDC said, the vast majority of new infections took place in the metropolitan statistical areas.

The agency estimated there were 47,477 new infections in 2010, of which 37,934 involved people living in metropolitan statistical areas. And of the 28,851 HIV infections attributed to male-to-male sex, 23,559 (or 81.7%) occurred among people living in those regions.