Potent Antibodies Offer New AIDS Vaccine Design

August 17, 2011

Researchers say powerful antibodies may hold clues to developing an effective AIDS vaccine. The antibodies were isolated from individuals already infected with HIV.

Dr. Wayne Koff says the goal is to find a vaccine that will help the immune system fend off an HIV infection.

“Most vaccines work in terms of stimulating something known as antibody, which is a protein substance in the body. And they work because the antibody identifies the site on the virus. And it can attach onto the virus and kill it,” he said.

Koff, chief scientific officer for IAVI, the International AIDS Vaccine Initiative, said the problem with HIV is that it’s a hyper-variable virus.

That means it’s different all over the world. And so instead of a single strain or a couple of strains, we have millions of strains. And as a result, for a vaccine, instead of eliciting a neutralizing antibody, what one is attempting to do is to identify where the vulnerable sites on the virus that are the same on every virus particle. And these antibodies then are known as broadly neutralizing antibodies. So if you’re exposed to a virus on one side of the globe, they would work just as well as if you’re exposed in some other region of the world.

HIV becomes hyper-variable when it replicates. Each time, it’s just a little bit different. Some scientists call these changes minor errors, but it’s enough to confound the human immune system. The changes occur in the outer protein of the virus, the target of neutralizing antibodies. In other words, the weak spot.