Emory Report

 November 10, 1997

 Volume 50, No. 12


Yerkes' Robinson making
strides toward AIDS vaccine

While combination drug cocktails may have been grabbing all the headlines recently in the fight against AIDS, Harriet Robinson believes the real future in eliminating the deadly disease lies in prevention, not treatment.

That's why Robinson came down south from the University of Massachusetts Medical Center to become chief of microbiology and immunology at the Yerkes Center. She believes a vaccine is within reach, and Yerkes offers unparalleled capabilities for the monkey models she needs to take the next step. And with Emory's new Vaccine Research Center currently under construction on the Yerkes grounds, Robinson knew the commitment was here to do major work in her field.

"It's a little bit like the Manhattan Project," Robinson joked about the "critical mass" of researchers being gathered in the Vaccine Center. "Yerkes is a remarkable resource because of its breeding colony. It's very exciting."

Robinson has been working with retroviruses for much of her career, and she became internationally known for discovering that DNA can be used as a safe and effective vaccine against certain diseases. It's through this kind of work that she hopes to provide an answer to the lethal question of AIDS.

"The whole field of AIDS vaccines has made a lot of progress over the past five to six years," she said. "Models have been developed for testing vaccines, and a number of people have shown what doesn't work, so we can appreciate the complexity of what needs to be done."

Yerkes' colony of rhesus macaques is perfect for Robinson's next phase of research because it affords her the opportunity to develop vaccines for the newborn as well as the adult. "The ideal situation is to be able to vaccinate the newborn," she said.

A group of doctors has made news with their plans to circumvent the Food and Drug Administration's strict controls on human trials and test live-attenuated vaccines-basically live AIDS viruses-by injecting themselves; they may have changed their minds after a group of macaques recently came down with the disease five years after being vaccinated. A big advantage of Robinson's DNA vaccines is they contain no infectious agents and thus pose no threat of infection.

"The DNA only codes for part of the virus," Robinson said. "One of the goals is to get the immunizations as effective with DNA as with the live-attenuated virus.

A high priority for Robinson is to start trials in humans in parallel with those in macaques. "It is essential to know how immune responses in humans compare to those we are raising in macaques," she said. "We can challenge the macaques to determine efficacy and the immune correlates for protection. But our goal is a vaccine for humans, and to achieve this we will need to know whether we can raise the responses in humans that correlate with protection in macaques."

But Robinson feels confident about an AIDS vaccine. Each trial she designs lasts about two years, so that leaves four or five rounds of research to meet a decade deadline. It will be a lot of work, she said, and it may require more than a decade, but it is definitely doable.

Part of the reason for her optimism is the recent increase in vaccine research funding. Vaccines have been relatively neglected in AIDS research because early attempts failed and pharmaceutical companies have seen surer courses to producing drugs than a vaccine.

"It's risky for a large company-you give vaccines to healthy people, and you give drugs to people who are already sick," Robinson said. "You can charge large sums for the drugs you are giving so you can really get your costs back for your development. But when you get into vaccines, they have to be inexpensive, and they have to be absolutely safe."

But this is changing. The federal Office of AIDS Research recently increased vaccine funding by 40 percent, and individuals such as Nobel laureate David Baltimore, now the president of CalTech, are committed to vaccine work. Robinson said the work is critical because, while drug cocktail treatments may be effective in temporarily controlling the virus, they do not prevent the virus from reappearing when the treatment is stopped. The treatments are also very expensive and thus are of little use to Third World countries ravaged by AIDS.

"[Combination drug treatments] are really just a Band-Aid-they stop the bleeding but they don't allow permanent healing," she said. "When you get out to Third World countries where the total health budget per year is $3 per person, you have to have a vaccine. It's the only cost-effective way to prevent AIDS.

"And even though AIDS is decreasing in the United States, it is still a major problem. It's a major cause of death in young adults, which is the most productive age group economically."

-Michael Terrazas

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