AIDS-vaccine research has been in the doldrums. A project whose first discoveries were announced this week may put the wind back in its sails

THE scientific study of AIDS has dropped out of the headlines over the past year or two. The disease is still a mass killer, but the drugs used to combat it have become cheaper, and the mechanisms for getting them to the infected, most of whom live in poor countries (predominantly African ones), have got better. As to prevention, circumcision—though by no means a complete answer—has been shown to reduce a man’s risk of becoming infected with HIV, the virus that causes the disease, and thus helps slow down the rate of transmission. The drugs, too, seem to do that, by reducing the number of viruses in an individual’s body.

That is all good news. But it brings the field no nearer to what is really needed—a vaccine that will stop people getting infected in the first place. The last big vaccine trial, known as STEP, ended in failure in 2007. It may even have promoted susceptibility to the virus it was trying to curb. AIDS-vaccine researchers seemed to be running out of both ideas and hope. But a paper published in this week’s Science shows that neither of those things is true. There are still original ideas around. And there is also a revival of hope. …