U.S. government scientists have discovered two potent human antibodies that can stop more than 90% of known global HIV strains from infecting human cells, the National Institute of Health announced Thursday.
The scientists first discovered the two naturally occurring, powerful antibodies in the blood of an HIV-infected individual. Scientists found that the antibodies, called VRC01 and VRC02, not only neutralize more HIV strains, but they do so with greater strength than previously known antibodies.
So far, scientists have found the HIV virus extremely tricky to work with for the purpose of creating a vaccine. It has been difficult to find individual antibodies that can neutralize HIV strains anywhere in the world because the virus continuously changes to evade recognition by the immune system. Which also explains why so many HIV strains exist worldwide. Last year, the most promising vaccine trial to date managed to help only less than a third of the individuals.
Still, scientists were able to identify a few areas on HIV's surface that remain nearly constant across all variants. One such area is called the CD4 binding site. VRC01 and VRC02 block HIV infection by attaching to the CD4 binding site, preventing the virus from latching onto immune cells.
Still in the Lab
With this knowledge, researchers have begun the difficult work of designing a possible vaccine that could teach the human immune system to make its own antibodies similar to VRC01 that might prevent infection by the vast majority of HIV strains worldwide. So far, their work has been done only in cells in a laboratory.
"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," Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health said in a statement.
"The discoveries we have made may overcome the limitations that have long stymied antibody-based HIV vaccine design," Dr. Peter D. Kwong, one of the NIAID scientists who led the research, added.
Not only that, the method used to find these antibodies could be applied to isolate therapeutic antibodies for other infectious diseases as well.
25 Million Deaths So Far
The U.S. HIV/AIDS epidemic began in 1981, according to the NIAID, and 566,000 people in the U.S. have died of AIDS since. At the end of 2006, an estimated 1.1 million people in the U.S. were living with diagnosed or undiagnosed HIV/AIDS, and over 56,000 new infections were recorded. Globally, 33 million people have lived with HIV/AIDS, and 2 million died of related illnesses in 2007. And since its discovery, 25 million people have died of AIDS worldwide. Although drugs can help control the disease, there's still no vaccine for it.
That makes today's announcement by the NIH all the more important -- and hopeful.
Scientists Discover Antibodies That Could Help Create AIDS Vaccine