Federal health officials recommended Wednesday that hundreds of thousands of Americans at risk for AIDS take a daily pill that has been shown to prevent infection with the virus that causes it.
If broadly followed, the advice could transform AIDS prevention in the United States — from reliance on condoms, which are effective but unpopular with many men, to a regimen that relies on an antiretroviral drug.
It would mean a 50-fold increase in the number of prescriptions for the drug, Truvada — to 500,000 a year from fewer than 10,000. The drug costs $13,000 a year, and most insurers already cover it.
The guidelines tell doctors to consider the drug regimen, called PrEP, for pre-exposure prophylaxis, for gay men who have sex without condoms; heterosexuals with high-risk partners such as drug injectors or male bisexuals who have unprotected sex; patients who regularly have sex with anyone they know is infected; and anyone who shares needles or injects drugs.
Officials at the Centers for Disease Control and Prevention have long been frustrated that the number of H.I.V. infections in the United States has barely changed in a decade, stubbornly holding at 50,000 a year, despite 30 years of official advice to rely on condoms to block transmission.
Although there is no guarantee that gay men will adopt the drug regimen, federal officials say something must be done because condom use is going down. In a C.D.C. survey in November, the number of gay men reporting recent unprotected sex rose nearly 20 percent from 2005 to 2011.
Nevertheless, advocates for the drug regimen were elated at Wednesday’s announcement.
“This is wonderful,” said Damon L. Jacobs, a therapist in Manhattan who is HIV negative, has been on the regimen since 2011 and runs a Facebook page promoting it. “When an institution like the C.D.C. makes a statement, it makes a profound difference to the doctors who are ambivalent.”
Dr. Jonathan Mermin, director of the C.D.C.’s national center for AIDS and other sexually transmitted diseases, said the new guidelines should save many lives.
“On average, it takes a decade for a scientific breakthrough to be adopted,” he said. “We hope we can shorten that time frame and increase people’s survival.”
While many antiretroviral drugs could in theory be used for the drug regimen, the only pill approved for that purpose by the Food and Drug Administration is Truvada, made by Gilead Sciences.
Truvada, a mix of tenofovir and emtricitabine, is considered relatively safe with few side effects. Generic versions are made in India, and it has become the backbone of AIDS treatment in poor countries.
Common side effects include headache, stomach pain and weight loss. Rare but serious ones include liver and kidney damage.
Officially, the C.D.C. is endorsing the drug regimen only in conjunction with condoms. But health officials say they know that some people will stop using them. Many gay men, including Mr. Jacobs, report doing just that.
That raises their risk of contracting other diseases, like syphilis and gonorrhea. But health officials argue that the benefits of taking the drug regimen outweigh the risks.
“Making the perfect the enemy of the good is something we’ve got to get over,” said Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases and the country’s best-known AIDS doctor. “I strongly support the C.D.C. doing this.”
Syphilis and gonorrhea can usually be cured with antibiotics, but H.I.V. lasts for life and is fatal if left untreated. Even those treated properly often develop early heart disease and other problems.
Since 2010, three separate studies using Truvada have shown that when taken daily it can vastly reduce the chances of infection. That held true for gay men, heterosexual couples and drug injectors. In the study of gay men, known as iPrEx, men whose blood tests showed they had taken their pill every day were 99 percent protected.
The new guidelines say patients should have an H.I.V. test before starting the regimen, to make sure they are not already infected. (Prophylaxis involves doses of two drugs, but anyone with the disease should be on triple therapy.)
Patients should be retested every three months to be sure that they are still H.I.V. negative, that they are not developing side effects from the drug and that they have not caught any other sexually transmitted diseases.
While many AIDS specialists endorse the drug regimen, it has not caught on among doctors as a whole.
A survey of 1,175 infectious disease specialists in the United States and Canada published in December showed that 74 percent supported it, but only 9 percent had actually prescribed it.
“There’s a lot of inertia among doctors, and a strong statement from the C.D.C. will be pretty valuable for overcoming that,” said Dr. Demetre C. Daskalakis, an AIDS specialist at Mount Sinai Hospital in New York who has many patients on the regimen.
Also, the drug regimen has not caught on among gay men, who are by far the largest risk group.
By analyzing pharmacy databases, Gilead has tried to track how many Truvada prescriptions are for the drug regimen, rather than AIDS treatment. As of last September, the company said, it knew of only 2,319 — of which 49 percent were for women.
Advocates said there were several reasons there had been little clamor for the drug regimen. First, while many doctors prescribe statins as prophylaxis against heart attacks, for example, only AIDS specialists are likely to prescribe AIDS drugs as prophylaxis. But uninfected gay men have no reason to see AIDS specialists, and usually see general practitioners if they see doctors at all.
Also, Truvada is expensive. However, private insurers and state Medicaid programs have thus far generally covered such prescriptions, and Gilead has a program covering co-pays and giving Truvada to the uninsured.
“In my experience, it’s a simple process to get the meds approved,” Dr. Daskalakis said.
Another reason is that Gilead does not advertise Truvada for prophylaxis, even though the F.D.A. approved it for that use in 2012 and Gilead does advertise it for treatment, for which it was approved in 2004.
A company spokeswoman said it had no plans to do so, but it does make grants to gay organizations that espouse the drug regimen.
Not advertising helps Gilead avoid controversy.
Michael Weinstein, president of the AIDS Healthcare Foundation, has called Truvada a “party drug” and argued that the drug regimen would encourage men to avoid condoms and thus increase the infection rate. He called the release of the guidelines “a shameful chapter in the history of the C.D.C.”
That debate has played out on gay websites, where men favoring the drug regimen are often stigmatized as “Truvada whores.” (The term was coined in a 2012 Huffington Post article whose author has since publicly regretted his stance.)
“People are reacting out of fear,” Mr. Jacobs said. “Gay men who embraced the condom message and survived the trauma of 30 years ago have PTSD. This is a paradigm shift, and people don’t like change.”
Recently, a lash against the backlash has emerged, with a few men proudly wearing “Truvada Whore” T-shirts, just as others proudly wear “Queer” or “H.I.V. Positive” ones.
Adam Zeboski, a test counselor for the San Francisco AIDS Foundation, makes and sells “Truvada Whore” T-shirts to raise money for the foundation.
“People are both very supportive and very offended,” he said. “By reclaiming the ‘Truvada Whore’ term, we’re taking the power away from those who use it against us.”