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Over the last six months, scientists have revealed they've learned a lot more about human anti-bodies, which could lead to a better designed AIDS vaccine candidate.
Anti-bodies are proteins that fight off infection from viruses, bacteria and other foreign objects. However, they've not been able to mount enough of a response to stop HIV, the virus that causes AIDS, in its tracks.
"Vaccine development historically relies on anti-body responses. Vaccines generally are meant to boost the immune response and to help the body fight off a coming attack," says Mitchell Warren, head of AVAC, AIDS Vaccine Advocacy Coalition.
He describes a strong anti-body response as "the secret of success for most vaccines. So it's been very much the target for AIDS vaccine research and development."
Looking for HIV weaknesses
"A lot of the research has been focusing on the actual structure," he says, "of the virus itself. And as we learn more about how the virus is structured, that may help us unlock how to develop a vaccine."
Some of the scientific techniques being used to study anti-bodies and HIV didn't exist 10 or 15 years ago.
"So what we're seeing now are the beginnings of the fruits of technological labor applied to the AIDS vaccine effort. And it's really just a beginning. We need to see a great deal more of that done to really unlock the promise of science," he says.
While anti-bodies respond quickly to many diseases, the immune response to HIV is not quick enough.
"HIV is highly mutating. So it's constantly changing to evade the immune system, which makes it very hard to lock down the immune response and a vaccine to help boost that," he says.
Taking a closer look
Early anti-body research regarding HIV concentrated on the outer layers of virus. But over the last six months scientists have reported possible new targets in different parts of HIV.
"We don't know exactly what to make of this and how to apply that to a vaccine yet, but the work now is to try to take advantage of these new targets," Warren says.
If indeed antibodies responded more quickly against HIV, could they defeat it?
"It hasn't yet," he says. However, there are people infected with HIV whose immune systems are able to fend off the virus without the help of anti-retroviral drugs. Similar findings are found in monkeys infected with SIV, Simian Immunodeficiency Virus.
"We're really at a point right now in AIDS vaccine research - more than ever before I think - where it's a question of how do you translate these...findings...into vaccine design and vaccine development. And that's really the next big step forward," he says.
He says things have changed in the last six months.
"We're in a new world in AIDS vaccine research. Does it mean we have a vaccine around the corner? No. But it does mean we have more kind of bricks in the foundation on which we need to build a vaccine than we've ever had," says the AVAC head.
Last year, a study of an AIDS vaccine candidate in Thailand indicated that it is possible to control HIV with a vaccine.