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AIDS researchers Eddy Arnold and Gail Ferstandig Arnold developed a unique technique to try to immunize the body against HIV. (Photo by Nick Romanenko) |
For more than 25 years, a vaccine for HIV has been the elusive Holy Grail that thousands of researchers around the world are looking for. Every time there is hope that a vaccine is close, it slips through their hands. But now, two researchers might have turned the corner in the long search.
Most vaccines are usually created from weakened or inactivated variations of the organisms that cause the disease itself. Once the body encounters these organisms and overcomes them, it develops immunity against their diseases in the future.
But the human immunodeficiency virus (HIV), which causes AIDS, is too dangerous to use in this manner, even if weakened. And when dead, important parts of the virus fall off during preparations. This makes it ineffective for use as a vaccine.
That is why Gail Ferstandig Arnold and Eddy Arnold, AIDS researchers at Rutgers University, New Jersey, developed a unique technique to try to immunize the body against HIV. They took a small part of the HIV and attached it to the virus causing common cold. This was then inserted in animals to trigger immunity against AIDS.
"The idea is to trick the immune system into thinking it is acting upon HIV before the virus actually shows up on the scene," Eddy Arnold told IslamOnline.net.
"In short, we're making safe mimics of HIV in the context of the safe, cold-causing rhinovirus," added Gail Ferstandig Arnold.
Colossal
While the concept may be simple, achieving it is far from that. The husband and wife duo and their team had to take parts of the HIV and add it to a completely different virus. And the end result had to look similar enough to HIV that the body develops immunity against the real virus. To Eddy, this is like taking the Rocky Mountains, putting them in India, and have them look exactly right.
Various different parts of HIV were combined with different parts of the common cold virus. The researchers created millions of these combinations in search of some that have potential. They then developed a technique to systemically test these variations as they are produced. This led to the formation of what is known as combinatorial libraries.
"We make viruses with all kinds of properties. Some of them clump together, some of them die, some of them are difficult to purify," pointed out Gail. "We end up only working with the recombinant viruses that are manageable to work with."
"It's like the lottery," Eddy commented. "The more tickets you buy the better chance you have of winning."
Tricky
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| For an AIDS vaccine to be effective in any way, it must be affordable for people in the developing world. |
Finding a vaccine for HIV is especially tricky due to the virus' remarkable ability to mutate on the fly. Today, there are many different variations of the virus around the world. While one vaccine may give protection against one type, this does not guarantee protection against another mutant variety in a different part of the world. This has made past efforts to elicit a vaccine very limited.
"We are targeting regions of HIV that are so important to the virus' ability to grow that they can't change much without disabling the virus," said Gail.
The different variations of recombinant viruses produced are inserted in animals in the lab. The animals begin producing antibodies and are then injected with isolates of different varieties of the AIDS virus to see if they develop protection.
"The part that we targeted plays a role in the ability of HIV to enter cells, and is common to most HIV varieties," continued Gail. "That is a mechanism that would not be easy for the virus to reinvent on the fly, so it turns out to be a really helpful target."
"Our best scenario so far was one where a recombinant virus immunized into a guinea pig protected against 9 out of 9 isolates tested from diverse parts of the world. This was a very exciting result."
Long Haul
But Eddy was quick to point out that it is too early to get excited about this promising research. "It is probably not potent enough by itself to be a vaccine, but it is a proof of principle that what we are trying to do is a very sound idea."
Gail points out that, realistically, this vaccine could offer partial protection. After vaccination, there is a lag period before a person's body starts generating antibodies. During this time, viruses that enter the body can start infecting cells. HIV binds to a cell and does not leave until it dies.
"What we think could happen with an effective vaccine is that fast and appropriate production of antibodies in vaccinated people could soon get the infection in check," she said. This would give the immune system a fighting chance to keep the infection at a minimum, extending a person's life – maybe indefinitely.
For an AIDS vaccine to be effective in any way, it must be affordable for people in the developing world who bear the brunt of the virus. But recombinant technology is known to be expensive and time-consuming. This could potentially limit the benefits of this approach.
But Gail hopes they can overcome this problem. "In the best case scenario, this type of vaccine could be given as a live rhinovirus vaccine. This would mean that a small dose could be used to infect a vaccinee, and it could multiply in the person's body, instead of having to produce large amounts in a laboratory."
The Arnolds are still hopeful this technique may open up new benefits. It can be a potential treatment for people infected with HIV before they develop AIDS to prolong their lives. "For a vaccine to work, the immune system has to work. This might give us a big window for treatment, since immunodeficiency doesn't usually develop until five to eight years after the initial infection," explained a hopeful Gail.
She is also hopeful this approach can be used to develop vaccines against other diseases and even certain types of cancer.
"Whenever we get encouraging results, we explore them. It's like a bootstrapping process, where you have to go step by step."
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