Ending AIDS Epidemic Seen as Multi-Front War

In a Spanish study of nearly 400 such "discordant" couples, 8.6 percent of the partners became infected before the infected person started taking the drugs. In couples in which the infected person starting taking the medicines immediately, no partners became infected.

This happens in whole populations, too.

Data from British Columbia presented this week showed that after triple therapy became widely used in 1996, new HIV infections dropped steeply even though syphilis -- which is also sexually transmitted -- rose for six of the next eight years.

In one of the more provocative presentations, Julio Montaner, the director of British Columbia's AIDS center in Vancouver, showed a mathematical model of what would happen if all identified cases of HIV infection were treated. The line depicting the prevalence of HIV went essentially to zero by 2050.

The total cost of treating AIDS also took a clear downward turn starting in 2015, as the number of new cases fell off.

"I will say it three times: This is theoretical, this is theoretical, this is theoretical," Montaner told the conference as his "End-of-AIDS" graph was projected onto a half-dozen screens in the cavernous main hall of the Metro Toronto Conference Centre.

This conference's slogan was "Time to Deliver," a reference to the urgency with which triple therapy needs to be brought to the developing world. Only 1.5 million people there are getting it, even though 6.8 million need treatment immediately. According to data presented here, many get treatment only when their disease is so far advanced that the drugs are much less effective.

Nobody expects everybody in the world who has HIV to be treated -- not soon, or ever. Nevertheless, Montaner's point impressed many.

"Treated people just simply become less infectious. This is win-win. This is not a subject that requires debate," said Mark A. Wainberg, head of McGill University's AIDS program and one of the co-chairs of the meeting.

The real power of treatment's preventive effect is that it would synergize with other preventive strategies that may roll out a massive scale in the next five to eight years.

Microbicides got a huge rhetorical boost here, as the two star speakers, Microsoft founder Bill Gates and former president Bill Clinton, both touted their promise.

Results are expected over the next three years on the ones now in field tests, which block HIV in nonspecific ways. However, researchers reported early tests of a vaginal ring imbedded with an antiretroviral compound called TMC120 that specifically kills HIV. A woman could keep the ring in for a month, and it would leach out the compound that entire time, protecting her. Further studies, including testing whether African women would accept such a device, are planned.

Also awaited are the results of two studies, underway in Africa and North and South America, testing whether daily doses of the drug acyclovir reduce the risk of HIV infection in people with genital herpes, and in their partners. Herpes infection doubles a person's chance of acquiring HIV and increases an infected person's chance of transmitting it fivefold.

Two big studies of circumcision, which earlier research suggests reduces a man's chance of getting HIV by 60 percent, will have results by the end of next year.

"We think that's great," said Mark R. Dybul, an AIDS physician recently sworn in as the head of the Bush administration's global AIDS program, operated out of the State Department. "You can't just have a treatment program. You have to have prevention and care and treatment."

The next conference will be held in two years in Mexico City.