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Hope for an AIDS Vaccine: Nearly Two Years Later, Thankfully, Still Waiting for Godot

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AFP

A rhesus macaque monkey much like Godot

The revelation made headlines a month ago: Thanks to a rhesus monkey named Godot, and his astounding good health in the face of repeated viral injections, researchers are increasingly optimistic about a new AIDS vaccine. Now, as scientists and activists descend on Philadelphia for the 2001 AIDS Vaccine conference, more details are emerging about this very welcome development. Researchers are pelted with questions: How has this vaccine kept Godot, a test subject at Emory Universityís Yerkes Regional Primate Research Center, so healthy, even as scientists injected him with deadly levels of the HIV virus? And, more important, given the same vaccine, would human immune systems mimic the monkeyís remarkable degree of resistance?

A closer analysis shows decidedly mixed news for AIDS sufferers and those at especially high risk for contracting the disease. "This is one of those classic good news/ bad news stories," says Dr. Jeffrey Laurence, professor of medicine at Cornell Medical Center and senior scientist for programs at the American Foundation for AIDS Research (AMFAR). "On the one hand, itís wonderful we can keep a monkey healthy even after heís injected with dangerous levels of HIV. But on the other hand, weíre not talking about something thatís immediately transferable to humans." Thereís also the issue of mutation, he adds. The virus is infamous for its ability to adjust to any attack, to alter its shape or defenses in order to escape detection or destruction from vaccines and treatments.

Further complicating the issue is the fact that while Godot appears healthy, he is still infected with the AIDS virus. That means even in the best case scenario, this "vaccine" might only be capable of keeping a personís viral load under control, or even imperceptible — but it would not block the virus from entering the body. That kind of non-vaccine vaccine, adds Dr. Laurence, has a demonstrable psychological downside.

"What do people think when you give them a vaccine that doesnít actually prevent the virus from entering the body? They think, oh, well, you wouldnít have given me this if it didnít work," Dr. Laurence says. "So people go out and engage in high-risk behaviors, because they feel invincible, and then we see the inevitable emergence of breakthrough infections."

Still, there are reasons to welcome this news. "We donít have an AIDS vaccine right now," says Dr. Laurence, "and itís generally accepted that the vaccines in trials right now have no chance of working. So news like this is very encouraging,"

Hopeful as the initial signs may be, however, donít look for the Yerkes vaccine to hit the U.S. anytime soon. The first place the vaccine would likely be used in a human form is in very high-risk areas like sub-Saharan Africa, where the infection rate has skyrocketed, immune systems are profoundly weakened, and any drug capable of depressing AIDSís virulence could save millions of lives.

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