The Search For Solutions

At the time, Emini didn't expect to spend the next 24 years fighting the virus. No one else did, either. Yes, AIDS was bad, but Margaret Heckler, the secretary of Health and Human Services, predicted that an HIV vaccine would go into trials within two years. It did, then it flopped, and so has every other attempt since then. The problem, which scientists still don't fully understand, is that HIV thrives on immune-system activity—and nothing boosts immune activity as effectively as a vaccine. "The objective for those of us who make vaccines," says Emini, "is to kill the bastard before it has the chance" to exploit the body's response to it.

Until last Friday, Emini thought he might be able to kill the bastard, or at least cripple it. At Merck, in the mid-'90s, he worked on a vaccine, adding HIV genes to the "adenovirus" that causes the common cold. Tests on monkeys looked promising. Before human trials started, Emini left Merck, in 2003, to head the International AIDS Vaccine Initiative. In 2005, he moved to Wyeth Pharmaceuticals and launched more HIV vaccines there. But he kept track of his old vaccine. Many people did: it was probably the most promising candidate around. "Was," because last Friday, Merck pulled it. The vaccine was brilliantly designed and apparently safe, but like the string of failures that preceded it, it simply didn't work.

This is the biggest disappointment HIV researchers have had in years. A few scientists have even begun to suggest that the virus is vaccine-proof. Emini is not one of them. "This is not the time to give up," he says. His Wyeth team is now pursuing several approaches, and there are dozens more, based on every tactic scientists can think of. Most are percolating in petri dishes, but one, from SanofiPasteur, has gone slightly farther in clinical trials than Merck. Those who continue to do this kind of work have extraordinary faith that they'll succeed. If any of the new vaccines is even a little helpful, "we'll be happy, really happy," says Dr. Jose Esparza, an HIV expert at the Bill and Melinda Gates Foundation. "If we get one that's 40 percent effective we'll open a bottle of champagne."

In the meantime, Emini has plenty else to do. He's working on other vaccines at Wyeth, most notably "Prevnar 13," which he calls "the most complex biological product ever made." Its chemistry is remarkable: it is essentially 13 vaccines in one. A new variation on an existing shot, it targets 13 strains of the pneumonia-causing pneumococcus bacterium, some of which are found mainly in the developing world. It's currently in latestage trials.

There's a carrot on a stick for firms that work on pneumococcal vaccines: a unique type of funding called an "advance market commitment." Last year several wealthy countries, mostly in Europe, announced that they wanted a vaccine for pneumococcal disease. Make a good one that developing countries will want, the donors said, and we'll buy it from you and give it to them. You'll recoup your investment, they'll get their medicine, and we'll know our money made a difference. Future AMCs may target vaccines for malaria, TB and yes, AIDS. There's already plenty of incentive to develop an HIV vaccine: there's a Nobel Prize out there. But an extra push couldn't hurt. As Emini knows too well, defeating HIV may take every weapon the world has to offer.

As it happens, David Edwards, 46, is working on a new one, though it's not intended for HIV—yet. A biomedical engineer at Harvard University, he speaks softly and quickly, like a man who needs to finish talking because there are a thousand more important things he should be doing. His research, translated into action, could save millions of lives. But he is modest about it; praise him and he'll shrug, saying what he does is simply "a combination of art and science." His colleague, Barry Bloom, the dean of Harvard's School of Public Health, is more effusive: he calls Edwards's biggest innovation "way out."