A chance to save lives

Mosaic proteins hold the promise of becoming the first viable vaccine to protect people from the virus that causes AIDS.

Bette Korber of the Los Alamos Theoretical Biology and Biophysics group types a command on her computer and brings up a graph replete with more than a dozen sets of vertical lines.

“This is what caught everyone’s attention,” she says softly, pointing to a set of multicolored lines strikingly longer than the others. “It shows that in rhesus monkeys, at least, the artificial mosaic proteins elicit a significantly broader immune response than natural proteins. As a vaccine they should offer greater protection against rapidly evolving viruses like HIV.”

The human immunodeficiency virus, HIV, causes a weakening of the body’s immune system. It infects—and cripples—the helper T cells (CD4+ cells) that are critical to a healthy immune response, and though people can live with HIV infection for years without treatment, at some point the disease progresses to acquired immune deficiency syndrome, or AIDS, the 100 percent fatal end stage that is characterized by an immune system too compromised to stave off various opportunistic infections. HIV is also known to act synergistically with other diseases, such as tuberculosis, and may be linked to the 4-fold increase in tuberculosis in countries where HIV is rampant.

In the thirty-some years since HIV was identified, the virus has wreaked a global pandemic of fearsome proportions: 27 million dead, 33 million infected, and rates of 3 million infections and 2 million deaths per year. Put another way, if the virus had plagued only the United States, more people than currently live in Texas and New Mexico would have already died from AIDS; everyone in the coastal states of New Jersey, Maryland, Delaware, Virginia, North Carolina, and the District of Columbia would be living with HIV; all of Chicago would likely become infected this year; and the nation should prepare to bury everyone in Indianapolis, Denver, and Albuquerque by year’s end. So far, the health-research community has been unable to create a widely applicable vaccine that could curtail the spread of the virus. There are many reasons for that, the main one being that HIV is one of nature’s great quick-change artists—the virus mutates so fast that some version always emerges that goes unrecognized by a person’s immune system.

But there’s newfound hope for containing or reversing the spread of HIV and eradicating AIDS. Korber’s eclectic team of immunologists, biologists, physicists, and computer programmers developed the mosaic proteins—so named because they are constructed from many small protein pieces—specifically to help the immune system fend off HIV. They just might have succeeded.

An immunologist and evolutionary biologist of international distinction, Korber is quick to mention that research on a mosaic-protein vaccine is still in its early stages, that it isn’t known yet whether the vaccine will be effective in humans. Phase I trials, led by Barton Haynes of Duke University, have barely gotten under way; they will check the safety of the proposed vaccine’s components and see the efficacy of the immune response in humans. If the results are promising, a vaccine comprised of three or four mosaic proteins will be tested in a large-scale human trial to assess its level of protection.

“This has been my life’s work,” says Korber. “While there’s much more to do, many indicators suggest we’re on the right track.”

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