Doctors try new tack for HIV vaccine

(CNN) -- Along with searching for new medications to control the ravages of AIDS and HIV, scientists are striving to devise a vaccine that would stop the virus in its tracks, preventing people from getting ill if exposed.

VIDEO Researchers believe they have made an advance in developing an HIV vaccine, CNN's Christy Feig reports (September 10) Play video (QuickTime, Real or Windows Media)

But their work isn't easy. One of the main roadblocks scientists face has been determining which portion of the virus to target.

HIV is constantly changing, meaning any vaccine could eventually lose its effect.

Now researchers at the Institute of Human Virology in Baltimore, Maryland, have made a discovery that could help scientists beat that tricky aspect of HIV.

CNN's Christy Feig explains their findings.