HIV Digest	HIV Digest Archive

Approximately 200 gay men in Atlanta will be among the first 3,000 people in the world to test a new HIV/AIDS strategy: a pill to prevent HIV infection. This spring, three studies-- including one funded by CDC-- will examine whether the drug tenofovir (Viread) can stop HIV from causing infection. Currently used to treat HIV patients, tenofovir works by blocking reverse transcriptase, an enzyme HIV needs for replication.

The $3.5 million CDC study will enroll men who have sex with men, 200 at the AIDS Research Consortium of Atlanta and 200 in San Francisco. A $6.5 million Bill and Melinda Gates Foundation trial will involve 1,200 women in Cameroon, Ghana and Nigeria, and 400 heterosexual men in Malawi. And a $2.1 million National Institutes of Health trial will include 900 Cambodian women, mostly sex workers.

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In each study, half of participants will receive tenofovir and half will receive a placebo. All participants will be advised to practice safe sex and given condoms. Regimen adherence, side effects, viral resistance and high-risk behaviors will all be tracked.

Animal studies have suggested tenofovir might prevent HIV infection. Some doctors have begun prescribing the drug, combined with another medicine, as a "morning-after pill" when patients report having risky sex. Physicians also note growing street use of tenofovir among gay men as prevention before sex. That is one reason CDC wants to study whether the drug is safe and effective in HIV-negative people, said Kathryn Bina of CDC's National Center for HIV, STD and TB Prevention.

Experts caution that tenofovir is no magic bullet. It has side effects, and allowing large numbers of at-risk people to take it intermittently could lead to drug resistance. Some worry that the security of taking a pill that would not be 100 percent effective could lead to more high-risk sex or drug use. Taken daily, tenofovir costs about $4,600 a year-- $12.67 a day.

Editor's Note: from the Atlanta Journal-Constitution