OB-JE198_0708va_G_20100708104535

Great news:

In a significant step toward an AIDS vaccine, U.S. government scientists have discovered three powerful antibodies, the strongest of which neutralizes 91% of HIV strains, more than any AIDS antibody yet discovered.

Looking closely at the strongest antibody, they have detailed exactly what part of the virus it targets and how it attacks that site.

The antibodies were discovered in the cells of a 60-year-old African-American gay man, known in the scientific literature as Donor 45, whose body made the antibodies naturally. Researchers screened 25 million of his cells to find 12 that produced the antibodies. Now the trick will be for scientists to develop a vaccine or other methods to make anyone's body produce them.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.