It would seem that an AIDS Vaccine is a step closer. The journal Science has reported the discovery of antibodies that can defend against a wide scope of AIDS viruses and that may be employed in designing a vaccine against the as yet incurable virus.

The bodies of a small number of people produce these immune system proteins after they are infected with the AIDS virus, after it is too late to do much good. But a correctly designed vaccine might help the body manufacture them much sooner. Two of the antibodies discovered can attach to and counteract 90 percent of the several mutations of the human immunodeficiency virus that leads to AIDS.

AIDS infects around 33 million people worldwide, according to the United Nations AIDS agency UNAIDS., and has killed 25 million people since the early 1980s. As yet, there is no vaccine nor cure, however drugs help control it.

aids virus vaccineThe virus is tough to fight partly because it targets immune system cells and partly because it mutates continuously, making it a hard to hit moving target for both drugs and the immune system. Once a person is infected, the virus stays a step ahead of the immune system.

It has, so far, been impossible to design a vaccine that will affect the virus. Scientists announced their greatest success yet with a vaccine that seemed to slow the rate of infection, in volunteers, by about 30 percent. But, many questions remain. Scientists have been searching for parts of the virus that don’t mutate in order to develop vaccines that will protect against the continuously changing type.

Research teams have found two of the antibodies in the blood of patients infected with HIV who have not fallen ill despite the infection. Labeled “non-progressors” their immune systems have found ways to control the virus better than most of the infected. It appears that immune system cells called B-cells are making these particular antibodies.

Work at the University of Florida has been successful in capturing a 3D AIDS virus photo. Other investigators were able to freeze one of the antibodies in the process of binding to and disabling the virus, getting the image in a process called x-ray crystallography. Visualizing the virus’ structure may enable researchers to design a vaccine using a technique called rational vaccine design, similar to an established process for manufacturing drugs called rational drug design. Gene therapy may also help patients make these antibodies themselves, or employ an older procedure that transfuses the antibodies immediately.

One of the antibodies, called VRC01, partially imitates the manner an immune cell called a CD4 T-cell binds to a piece of the AIDS virus called gp120. The antibodies fix to a virtually unchanging portion of the virus, and this defines why they can counteract such an exceptional range of HIV strains.

The discovery of these extraordinary, broadly neutralizing antibodies to HIV and the structural anatomy that unravel how they work are dramatic advances that will hasten efforts to find a preemptive HIV vaccine for global use. Also, the techniques used to find the new antibodies constitutes a novel approach that could be used in vaccine designs for other infectious diseases.

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