Science and Health

3 big developments make AIDS outlook more hopeful

(Agencies)
Updated: 2010-11-26 09:31

In the nearly 30 years the AIDS epidemic has raged, there has never been a more hopeful day than this.

Three striking developments took place Tuesday: UN officials said new HIV cases are dropping dramatically worldwide. A study showed that a daily pill already on pharmacy shelves could help prevent new infections in gay men. And the pope opened the way for the use of condoms to prevent AIDS.

"I don't know of a day where so many pieces are beginning to align for HIV prevention and treatment, and frankly with a view to ending the epidemic," said Mitchell Warren, head of the AIDS Vaccine Advocacy Coalition, a nonprofit group that works on HIV prevention research. "This is an incredibly opportune moment and we have to be sure we seize it."

President Barack Obama said the groundbreaking research on the AIDS drug "could mark the beginning of a new era in HIV prevention."

The U.N. report said that new cases dropped nearly 20 percent over the last decade and that 33.3 million people are living with HIV now.

"We can say with confidence and conviction that we have broken the trajectory of the AIDS pandemic," said UNAIDS Executive Director Michel Sidibe in Geneva.

Health officials credit part of the decline to wider condom use, and on Tuesday, in a historic shift in church teachings, the Vatican said that using a condom is a lesser evil than infecting a sexual partner with HIV.

Condoms remain the best weapon against AIDS, and the new prevention pill is not the chemical equivalent. But scientists called it a true breakthrough. The pill, Gilead Science's Truvada, is already used to treat people with HIV. A three-year global study found that daily doses cut the risk of infection in healthy gay and bisexual men when given with condoms, counseling and other prevention services.

The drug lowered the chances of infection by 44 percent, and by 73 percent or more among men who took their pills most faithfully. Researchers had feared the pills might give a false sense of security and make men less likely to use condoms or to limit their partners, but the opposite happened _ risky sex declined.

The results are "a major advance" that can help curb the epidemic in gay men, said Dr. Kevin Fenton, AIDS prevention chief at the U.S. Centers for Disease Control and Prevention. But he warned they may not apply to people exposed to HIV through male-female sex, drug use or other ways. Studies in those groups are under way.

Because Truvada is already on the market, the CDC is rushing to develop guidelines for doctors who want to use it to prevent HIV, and urged people to wait until those are ready.

As a practical matter, price could limit use. The pills cost $5,000 to $14,000 a year in the United States, but roughly $140 a year in some poor countries where they are sold in generic form.

Whether insurers or government health programs should pay for them is one of the tough issues to be sorted out, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

"This is an exciting finding," but it "is only one study in one specific study population," so its impact on others is unknown, Fauci said.

His institute sponsored the study with the Bill & Melinda Gates Foundation. The findings were published online by the New England Journal of Medicine.

It is the third AIDS prevention victory in about a year. In September 2009, scientists announced that a vaccine they are now trying to improve protected 1 in 3 people from getting HIV in a stu mothers.

Taking these drugs before exposure to the virus may keep it from taking hold, just as taking malaria pills in advance can prevent that disease when someone is bitten by an infected mosquito.

The strategy showed great promise in monkey studies using tenofovir (brand name Viread) and emtricitabine, or FTC (Emtriva), sold in combination as Truvada by California-based Gilead Sciences Inc.

The company donated Truvada for the study, which involved about 2,500 men at high risk of HIV infection in Peru, Ecuador, Brazil, South Africa, Thailand and the United States (San Francisco and Boston). The foreign sites weres 92 percent.

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The treatment was safe. Side effects were similar in both groups except for nausea in the Truvada patients. Weight loss also was more common in the drug group, but it occurred in very few. Further study is needed on possible long-term risks.

All participants will get a chance to take Truvada in an 18-month extension of the study to see if men will take the pill more consistently if they know it helps, and whether that provides better protection. About 20,000 people are enrolled in other studies testing Truvada or its component drugs around the world.

The government will review all ongoing prevention studies, such as those of vaccines or anti-AIDS get counseling and reduce their number of sexual partners.