After years of disappointment, researchers have finally found a potential basis for an HIV vaccine. Scientists have discovered two potent human antibodies that can stop more than 90 percent of known global HIV strains from infecting human cells in the laboratory. According to the researchers, these antibodies could be used to design improved HIV vaccines or could be further developed to prevent or treat HIV infection. Moreover, the method used to find these antibodies could be applied to isolate therapeutic antibodies for other infectious diseases as well.

The World Health Organization reports that HIV/AIDS remains the world’s leading infectious killer. The disease accounted for an estimated 2 million deaths in 2008, and more than 33 million people are living with the disease worldwide. “The discovery of these exceptionally broadly neutralizing antibodies to HIV and the structural analysis that explains how they work are exciting advances that will accelerate our efforts to find a preventive HIV vaccine for global use,” says Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID).

The research team at the NIAID Vaccine Research Center isolated two antibodies called VRCo1 and VRCo2 in individuals infected with HIV. This discovery marks a great triumph for the fight against HIV because these antibodies neutralize more HIV strains with greater strength than previously known antibodies.  NIAID scientists Peter D. Kwong, Ph.D., John R. Mascola, M.D., and Gary J. Nabel, M.D., Ph.D., led the two research teams. A pair of articles about these findings appears today in the online edition of Science. “We have used our knowledge of the structure of a virus — in this case, the outer surface of HIV — to refine molecular tools that pinpoint the vulnerable spot on the virus and guide us to antibodies that attach to this spot, blocking the virus from infecting cells,” explains Dr. Nabel, the VRC director.

The researchers say the discovery put them one step closer to their goal, and among their next steps are plans to make sure other people – not just individuals with HIV – can create these types of antibodies, and figure out how to mass produce more antibodies to block HIV strains in the immediate future.