Miami Herald, Friday, December 8, 1989
Herald Staff

Until recently, pessimism has dominated the field, and many of the world's most prominent AIDS researchers doubted that finding a vaccine to prevent AIDS was possible. Despite their current excitement, experts still stress that they are years away from producing an effective human vaccine.

But the new work provides the first compelling evidence that a vaccine can protect animals from infection with a close genetic relative of the virus that causes AIDS in humans. More than a dozen efforts had failed.

"The major significance of this work is that (it shows) a vaccine is possible for an AIDS virus," said Michael Murphey-Corb, who heads a team at the Delta Regional Primate Research Center in Covington, La., that developed the vaccine.

The vaccine "is the most significant advance in the vaccine field since we started the AIDS vaccine program. It is a giant leap," said Dr. Wayne Koff, the chief of AIDS vaccine research at the National Institutes of Health, which funded the work.

Murphey-Corb and her colleagues at Tulane University's research center made their vaccine from an inactivated form of simian immunodeficiency virus (SIV). In its active state, SIV causes AIDS in monkeys and is genetically similar to the the human immunodeficiency virus (HIV), which causes AIDS in humans. A report on the research is being published in today's issue of the journal Science.

Traditional vaccines for illnesses like mumps or measles rely on weakened or inactivated viruses that, when injected into a person in very low doses, fool the immune system into "thinking" an infection is under way and making antibodies to attack the virus. By weakening the virus, scientists render it incapable of causing infection.

Murphey-Corb said she and her colleagues treated SIV with the chemical formalin, which locks the virus in a chemical straitjacket so it cannot cause disease.

Until now, conventional approaches have not worked with AIDS, in part, scientists believe, because the virus is a retrovirus -- a different kind of virus from the ones prevented by all existing vaccines -- and because it destroys the very immune system that a vaccine must enhance.

To test the vaccine, nine monkeys were given four immunizations over 13 months. Then, the researchers injected them with active versions of the deadly virus used to make the vaccine. Five "control" monkeys that received no vaccine also were injected with the active virus.

The results were dramatic. Within seven months of the time the animals were injected with the virus, all five of the control monkeys had become infected, and three had died. By comparison, none of the nine vaccinated monkeys had become sick. And only one shows any sign of infection.

"This is making me feel better than I have in years," said Dani Bolognesi, who is leading an effort at Duke University to develop an AIDS vaccine and who wrote a commentary accompanying the report in Science. "There are a lot of things we still don't know. What we do know is that there is a vaccine that can stop this virus.

"If we can achieve protective immunity this way, there is nothing to stop us from achieving it in humans as well."

But he and others involved in the development of AIDS vaccines said much work remains to be done before a vaccine is available for humans. They stressed that, although SIV causes a disease in monkeys that mirrors AIDS almost exactly, monkeys are not humans, and what works on them may fail on people.

"We shouldn't be fooled into thinking that a magic solution is around the corner," said Ron Desrosiers, a professor of microbiology at Harvard Medical School. "We have a very long road ahead, but at least we know where to go now."
891208
MH891203

AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.

Copyright ©1980, 1989. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content. .