A cure for AIDS remains a distant prospect but a host of drug treatments and other advances have fueled fresh hope that new human immunodeficiency virus infections may some day be halted for good.
Strategies for ending the 30-year AIDS epidemic through advances in treatment, testing and prevention are high on the agenda of a major meeting of experts in HIV/AIDS when it returns to the United States next week after two decades.
"What we know is absolutely possible is that we can end the pandemic even without having a cure," said Anthony Fauci, a leading AIDS expert and director of the National Institute of Allergy and Infectious Diseases.
Held every two years, the International AIDS Conference has convened elsewhere around the world but not in the US since 1990, due to a travel ban on HIV-positive individuals.
The ban was overturned by US lawmakers under president George W. Bush in 2008 and signed into law by President Barack Obama in 2009.
The conference's return to the United States was expected to draw a star-studded crowd of 25,000 -- more than the usual 20,000 -- including celebrities, politicians, AIDS activists and scientists, organizers said.
Among the key speakers are singer Elton John, former US president Bill Clinton and philanthropist Bill Gates. Democracy icon Aung San Suu Kyi of Myanmar will address the conference by videolink.
A pre-conference bash staged by amfaR, the American Foundation for AIDS Research, on July 21 will feature actors Sean Penn, Sharon Stone and prominent CNN newsman Anderson Cooper, who recently came out publicly as gay.
A series of pre-conference talks and announcements will also set the stage for the six-day meeting in the US capital, themed "Turning the Tide Together," which formally starts on July 22.
On July 19, French Nobel laureate Francoise Barre-Sinoussi, the co-discoverer of HIV, will announce the release of a new global strategy toward a cure that aims to tackle the reservoirs where HIV holes up after it has been attacked by antiretroviral drugs.
"The strategy aims to build a global consensus on the state of research in the HIV reservoirs field and define a roadmap of scientific priorities that must be addressed by future research to tackle HIV persistence in patients on antiretroviral therapy," said a statement by the International AIDS Society.
Another key point is the use of antiretroviral drugs as both treatment and prevention, building on a series of studies that have shown promise in giving the drugs to infected people early and even prescribing them to uninfected partners at risk.
"We see this as probably being a central conversation at the conference -- the appropriate initiation for treatment and also how to best take advantage of antiretrovirals for prevention more broadly speaking," said the World Health Organization's HIV/AIDS chief Gottfried Hirnschall.
The WHO will be releasing new guidelines for using HIV drugs as prevention, a strategy known as pre-exposure prophylaxis that has shown some success but also some failures in recent studies.
Funding gaps remain a big concern among experts, with the United Nations funding target set for $22-24 billion globally and the available cash for responding to HIV at just $15 billion in 2010.
Experts will also appeal for a jumpstart to current prevention strategies, which Fauci says have to accelerate in order to end the pandemic that has killed some 25 million people to date.
"If the current slow rate of decline in infections globally -- on average just 1.5 percent per year over the past decade -- were to continue indefinitely, controlling HIV/AIDS would remain a distant goal," he wrote in Health Affairs magazine in July.
Fauci and co-author Gregory Folkers, his chief of staff, called for optimal use of the prevention "toolkit" that researchers now have at hand.
In addition to antiretrovirals for treatment and prevention, those tools include microbicides that show some effectiveness against HIV when applied to the vagina or rectum, showing up to 54 percent fewer infections in women who used them at least 80 percent of the time.
Voluntary male circumcision has shown some success in Africa toward reducing HIV infection rates by 50 to 60 percent in heterosexuals compared to uncircumcised males.
And researchers are gleaning more clues from a 2009 vaccine trial in Thailand that showed a modest 31 percent reduction in HIV infection, and hope to improve on those results in future trials.