TOPICS > Health

A New Hope for AIDS

September 24, 1997 at 12:00 AM EDT


TOM BEARDEN: Los Angeles physician Dr. Charles Farthing is willing to put his life on the line to stop AIDS. He’s watched hundreds of patients die from the incurable disease and is frustrated that a vaccine hasn’t been developed to prevent it. So he’s volunteered to be injected with what is the most promising and most dangerous approach, a weakened or attenuated version of the HIV virus, itself.

DR. CHARLES FARTHING, AIDS Healthcare Foundation: I thought to myself, well, nobody is going to do it. If you really believe in something, you’ve got to put your money where your mouth is.

TOM BEARDEN: Dr. Farthing used the Internet to put out a call for other volunteers under the auspices of the International Association of Physicians in AIDS Care. So far, more than 50 doctors and AIDS activists have signed up to take a live virus vaccine. Live virus vaccines have been successful in conquering smallpox and polio. But they can also cause the disease they’re trying to immunize the body against. An attenuated AIDS virus vaccine could mutate into the infectious form and could also trigger cancer. Farthing says he isn’t particularly worried about that.

DR. CHARLES FARTHING: I think it’s just something that needs to be done. You have to remember HIV disease is a very slow disease. It would be even slower with an attenuated strain. If one was to fall ill, it would be many years time, and now we have very good treatments that, if taken intelligently at the beginning of disease and taken religiously, will control this disease.

TOM BEARDEN: The treatments Dr. Farthing is talking about have been effective, reducing the AIDS death rate in the U.S. by 23 percent. But they’re also expensive and third world countries can’t afford them. He thinks a vaccine is the only way to reverse the incredibly high infection rates there.

DR. CHARLES FARTHING: You know, there’s no money for the drugs there. There’s no resources. There isn’t the political will in the world to really help. And so the only way of slowing the disease there is to prevent its transmission. Safe sex education isn’t going to work, hasn’t worked, won’t work to any significant degree. So the only thing is a vaccine, and it really is an emergency.

TOM BEARDEN: Scientists have been searching for a vaccine ever since HIV was isolated in 1984. Back then President Reagan’s Secretary of Health & Human Services Margaret Heckler said the discovery would lead to a vaccine quickly.

MARGARET HECKLER: We hope to have such a vaccine ready for testing in approximately two years.

TOM BEARDEN: Thirteen years and 379,000 American AIDS deaths later there is still no vaccine. Dr. Ronald Desrosiers is a prominent AIDS vaccine researcher at Harvard University, who has been working on attenuated virus vaccines for many years.

TOM BEARDEN: Thirteen years ago HHS Secretary Margaret Heckler said we should have an AIDS vaccine in two years. What happened?

DR. RONALD DESROSIERS, Harvard University: Well, I guess it shows back then how little we really knew about how tough this virus was that we were dealing with. The–I think many of us shared her optimism and hope that we would have a vaccine relatively soon, but in the intervening period we learned how hard it is to make a vaccine against this virus.

TOM BEARDEN: One of the reasons it’s been so hard is lack of money. Development of any new vaccine relies heavily on the willingness of drug companies to spend millions of dollars to do research and to spend many years in clinical trials to prove a vaccine’s safety and effectiveness. And the AIDS virus provides formidable hurdles when it comes to the safety issues. Five years ago Dr. Desrosiers’ published study showing that monkeys vaccinated with an attenuated version of SIV, the primate equivalent of HIV, didn’t get sick when they were later given a lethal dose of full-strength SIV. Indications are a similar approach might well work for humans. Even so, drug companies are wary of the dangers of infecting healthy people even with a severely weakened HIV.

DR. RONALD DESROSIERS: The American free enterprise system is really not well suited to development of this sort of vaccine approach. There–we don’t know yet how safe this vaccine approach is, and I think any large company with a good degree of capital is–would be justly concerned about getting involved in this sort of thing because the liability issues could be enormous.

TOM BEARDEN: It was this kind of caution that led Dr. Farthing to volunteer his own body.

DR. CHARLES FARTHING: I kept asking, you know, what’s happened to Ron Desrosiers’ work, what’s happened to Ron Desrosiers’ work, and got more and more frustrated that nothing was happening. And I was told that drug companies, pharmaceutical companies would pursue it because they didn’t think there was any money in it, because they couldn’t get FDA approval to do studies, et cetera.

TOM BEARDEN: Dr. Farthing and others say drug companies are reluctant to invest in vaccines because the biggest demand comes from people least able to afford to buy the product. AIDS expert Margaret Johnston agrees.

MARGARET JOHNSTON, International AIDS Vaccine Initiative: 90 percent of new infections are occurring in developing countries and in populations that have the least ability to pay a high price for a vaccine. So what if they’re successful? Then they’re faced with the demand by people who can’t pay a large price to help recover their costs of putting in dollars.

TOM BEARDEN: Johnston is the scientific director for the International AIDS Vaccine Initiative, a group whose goal is to work with government and private industry to ensure an HIV vaccine gets to the marketplace. Johnston says the only solution is for governments worldwide to step up to the table and pay for the basic research.

MARGARET JOHNSTON: We have to find ways to get public dollars into that development process so the companies can do what they’re good at doing, which is bringing things to–which is bringing things to clinical trial, testing them, and see if they work. We also have to find ways to buy the vaccine, particularly for developing countries.

TOM BEARDEN: The Institute for Allergies & Infectious Diseases at the National Institutes of Health is about to get substantial additional funding in the wake of the President’s recent commitment to finding an AIDS vaccine within the next 10 years. Dr. Anthony Fauci heads the institute.

DR. ANTHONY FAUCI, National Institutes of Health: If we come up with a promising concept, I can assure you that you will see many companies jumping on the concept to develop a vaccine. What they really are looking for is an opening, a breakthrough, a concept, an avenue to approach.

TOM BEARDEN: Finding that breakthrough has been difficult because the basic science is much more challenging than anyone imagined because the disease is so tricky.

DR. ANTHONY FAUCI: It infects the cells of the immune system, itself, so the very component of the body that’s programmed to protect you against other infections is, in fact, the very target of HIV infection.

TOM BEARDEN: Complicating this is the fact that HIV often mutates, so a vaccine must protect against more than one strain. In fact, there are at least 10 different strains of HIV around the world, and researchers are uncertain whether any single vaccine will prove effective against all of them, and HIV is tougher to attack than other viruses because it becomes part of the body’s own gene sequence. As a result, any vaccine must reduce the immune system to attack not only the invading virus but the cells it is using to replicate itself.

Not that science isn’t trying, regardless of all the difficulties. Several different approaches much less risky than the attenuated virus are now in clinical trials. This fall volunteers like Zach Ryon in Denver are participating in the largest human trial to date of an approach that uses a genetically altered form of HIV. It’s a double vaccine. It consists of an animal virus called Canary Pox, which is harmless to humans, that has been changed so that it contains HIV genes. It also contains a protein called GP120 that stimulates the immune system.

ZACH RYON, Vaccine Volunteer: The potential benefits of having a vaccine against HIV are enormous. So if I can contribute to that in some way–obviously I’m not a doctor–so I can’t contribute any sort of medical advice or medical knowledge–but by being a sexually active gay male I can at least be a study participant.

DOCTOR: So you’ll need to fill this out tonight, which will include any symptoms you’re having, like if you’re tired, you have muscle aches, fever, nausea.

TOM BEARDEN: The scientific consensus is that Canary Pox trial will be safe but the vaccine may not be as effective as a live virus vaccine. Still, it seems like a turning point to Dr. Frank Judson, who heads the study in Denver.

DR. FRANK JUDSON, NIH Principal Investigator: Everything about AIDS has turned out to be far more complicated and far more challenging than people originally thought, so virtually every time schedule has had to be extended. However, more recently, I think we got cold feet in the process and put a number of vaccine trials on hold for the last three to four years. At this point, I think we’ve broken out of that and are back on track.

TOM BEARDEN: Scientists at the University of Pennsylvania, who are trying another approach, are also convinced they’re on the right track. They’re testing a vaccine based on manmade genetic material which they’ve injected into chimpanzees. The results were promising. The vaccine apparently helped the chimps fend off high doses of HIV.

DOCTOR: Do we have the same result in muscle cells at this point in time?

TOM BEARDEN: In theory this so-called DNA vaccine would bridge the gap between vaccines that are safe but only marginally effective and those that are effective but maybe too dangerous. Dr. David Weiner led the experiments.

DR. DAVID WEINER, University of Pennsylvania: They are customized and they often give rise to antibodies and killer T-cells. And so they represent a hybrid between these two distinct prior fields of vaccine development.

TOM BEARDEN: Dr. Weiner found a receptive bio-tech company called Apollon and small scale human trials began recently. But even with all the new energy going into vaccine development, a troubling ethical question remains: When is it safe enough to give healthy humans unproven vaccines, particularly the potential dangerous live virus varieties? Some believe that in developing countries like Tanzania, where up to 40 percent of the women in some urban clinics test positive for AIDS, the public health emergency is great enough to justify the risk.

DR. RONALD DESROSIERS: It basically boils down to a risk/benefit analysis. If your target population for the vaccine is a very high risk group where there is a high expectation for HIV I infection, then it becomes a risk/benefit analysis in terms of whether it’s worth the risk to try this live attenuated vaccine approach.

TOM BEARDEN: Back in Los Angeles Dr. Farthing says the time for debate is over.

DR. CHARLES FARTHING: I’m hoping that this publicity and this attempt to show people are willing to do it, to persuade people to do it, will persuade the companies to prepare a vaccine in the way we can use it.

TOM BEARDEN: Dr. Farthing and members of the AIDS physicians group will meet with federal health officials tomorrow to seek approval for the live virus test but say they will proceed without it if they have to.