False security

Federal health officials made a tacit admission May 14: Relying on condoms to prevent the spread of HIV isn’t working.

That day the Centers for Disease Control and Prevention issued guidelines recommending the prescription of a once-a-day drug for anyone at risk of becoming infected with HIV, including homosexual men who don’t use condoms, men and women with sex partners who might have the virus, and intravenous drug users. The United States saw an estimated 47,500 new HIV cases in 2010 alone, two-thirds of them among homosexual men.

Taken consistently, the drug, called Truvada, can protect a person from acquiring HIV. But it’s expensive, and some believe it may ultimately be ineffective at lowering disease rates. It could embolden some users toward promiscuous and risky behavior.

The Food and Drug Administration approved Truvada as the first prophylactic (pre-emptive) treatment against HIV in 2012. Relatively few people use it. One study that checked about half of U.S. pharmacies found just 2,319 prophylactic prescriptions for the drug as of last September, half written up for women.

Although cheaper than drugs needed to treat an HIV infection, Truvada is extremely expensive—$13,000 a year. The CDC’s recommendation will raise awareness of its availability and put pressure on doctors to offer prescriptions. If every person the agency defined as eligible for the drug started taking it—about half a million Americans—the undiscounted cost would rise above $6 billion a year, with much of the burden falling on insurance companies.

Surprisingly, Truvada has even divided AIDS experts. Dozens of AIDS groups endorsed the CDC’s policy last month, but the largest in the United States, the AIDS Healthcare Foundation, did not. The organization’s president, Michael Weinstein, has drawn sharp criticism for calling Truvada a “party drug.” He believes promoting it will give the gay community a false sense of security and lead to an increase in sex without condoms. Truvada only protects against HIV, so a person with multiple sex partners who takes the drug but doesn’t use a condom can still contract a host of sexually transmitted diseases.

“This is a position I fear the CDC will come to regret,” Weinstein said in a statement, warning it could have “catastrophic consequences” on the fight against AIDS.

“It’s good to prevent disease … even if the disease is caused by behavior we don’t approve of, whether it’s smoking or homosexual activity,” said David Stevens, the CEO of the Christian Medical & Dental Associations. But he is skeptical those at risk of HIV will remember to take a pill every day, an oversight that greatly diminishes Truvada’s effectiveness: “The best protection against HIV is not to engage in risky practices.”

Dwindling storm

The colossal storm on Jupiter known as the “Great Red Spot” is undergoing a big red shrink. Astronomers who observed the swirling anticyclone in telescopes in the 19th century estimated it to be about 25,000 miles wide, and a few decades ago the Voyager space probes measured it at 14,500 miles. Recent images from the Hubble Space Telescope reveal the storm at its smallest yet—just 10,250 miles in diameter.

A NASA astronomer said atmospheric eddies feeding into the storm might be altering its dynamics. It is still large enough to swallow the Earth. —D.J.D.