The Answer To AIDS?

A Vaccine To Stop The HIV Virus Is Now Being Tested

Research is now being conducted on a compound that could turn out to be nothing or could change the world. Called gp120, it might be the vaccine that prevents AIDS. If gp120 succeeds, it will be because one man, Dr. Donald Francis, wouldn't let it die.

Gp120 has powerful enemies. Funding for it has been eliminated again and again. But because of Francis, gp120 is now being injected into nearly 8,000 volunteers in the first full trial of a potential AIDS vaccine. Francis is one of the world's leading scientists in the field of infectious diseases and, as Correspondent Scott Pelley reports, he is now betting his career and reputation that gp120 is the answer to AIDS.
Francis has seen millions of lives wiped out by epidemics and millions of others saved by vaccines. He says the AIDS epidemic is the worst thing he's seen so far: "There are no human viruses that kill 100 percent of the people that they infect. HIV is extremely close to that 100 percent."

Francis is an epidemiologist living in the hills outside San Francisco. For him, epidemiology is science and shoe leather. He can tell you that stopping a plague takes a vaccine, courage and force of will; it's all about endurance.

Perhaps his greatest success was 25 years ago. Francis led a team from the federal Centers for Disease Control to Bangladesh and ended a centuries-old scourge one patient at a time

"We cornered small pox," says Francis. "Pushed it off the face of the Earth."

"If you can corner that last person and insulate them from everybody else, that is, put a wall of vaccinated people around them, there's no place for the virus to go," Francis says. "And it dies off."

A year later, in the horn of Africa, Francis landed in the middle of another fast-moving epidemic that killed within hours - both the victims and the doctors who treated them: the Ebola virus.

Francis says the work he was performing was dangerous: "We did autopsies on humans. And any of those, with a slip of a scalpel or a slip of a needle, would likely kill you."

Ebola and small pox taught the young epidemiologist two lessons: Risk everything and stop at nothing. And so in the late 1970s when a mysterious new epidemic developed in gay men, Francis knew that it would take prevention and ultimately a vaccine to stop it.

Francis was put in charge of the AIDS lab at the CDC, and that's when his problems began. In those days there wasn't much concern about an epidemic that seemed confined to gay men.

"It was a horrible time for everyone, horrible, horrible," says Don Hicks, one of the microbiologists working in Francis' lab. "I just think that they didn't have a concept of how serious it was - and how fast it would spread."

Francis tried to persuade the Reagan administration to spend money on AIDS prevention but was turned down. "The answer that was quoted to me that came down from Washington was, 'We'r supposed to look pretty and do as little as we can,'" he recalls.

To Francis, that was unacceptable. "For me personally, it was against my entire training as a doctor trying to maintain the health of the public to sit back and watch an epidemic burn," he says.

In 1984, Francis sent the newly identified HIV virus to the biotech company Genentech. The goal was to develop a vaccine to prevent AIDS, to stop the virus deadly life cycle.

Francis explains how AIDS develops: "There's the virus coming in the blood. It hits the receptors of the cell. Specifically, it's absorbed into the cell. And now, it goes into the cell and multiplies a thousand times. And that's AIDS."

The challenge was to make a vaccine that could prevent the virus from invading the cell. "Now, you've immunized the individual, and there are antibodies floating around in the blood," says Francis. "They stick to the virus. And the virus can't find the receptor, then drifts off and then dies on its own."

After six years of trial and error, Francis had a potential vaccine. He called it gp120. It was given to four chimpanzees, which were then exposed to massive doses of the AIDS virus, and it worked. Today, the vaccinated chimps have been HIV free for 10 years.

"The protection of the chimpanzees was literally a turning of the page of AIDS history," says Francis. "And now you're in a new chapter. Now the potential of a vaccine is real."

But it's a long way from primates to the Nobel Prize. Francis would have to prove his vaccine's effectiveness in humans, something that no one had ever tried before.

Among the skeptics was Dr. Anthony Fauci, head of infectious diseases at the National Institutes of Health and the person who controls the money for vaccine trials. "The science that I know, given the limitations of our knowledge of the immune response to HIV, vis-a-vis (a) vaccine, suggests to me that this is not going to be a home run," says Fauci. "And it might not even be a level of protection that would go anywhere."

But Francis counters this by saying, "My scientific opinion is it will work. But I don't know. You do a study to find out if it works....I wouldn't be doing this if I didn't believe it worked."

Francis quit the CDC in 1992 and joined Genentech, the company that had developed gp120. Together they managed to convince the NIH and Fauci to pay for a limited test of the vaccine in humans.

That first trial involved 57 volunteers, and it proved that gp120 was safe. A second trial, involving 296 volunteers, showed that the vaccine did induce an immune response, although seven of the volunteers became HIV positive.

"And that told us very much like other vaccines, that this vaccine is not 100 percent effective from the moment you get your first dose - not surprising," says Francis.

Gp120 was readied for a third and final trial - one designed to determine just ow effective the vaccine would be. Phase three would take thousands of volunteers and cost millions of dollars. Francis was sure that the NIH would fund it. A meeting was held on whether to proceed but Dr. Fauci decided the study shouldn't go ahead.

Says Fauci, "The feeling was that, given the limitation of resources, that the resources would best be utilized pursuing other directions. It was merely a matter of prioritization."

Fauci believes that too little is known about how HIV attacks the immune system to create an effective vaccine.

"Our understanding of the immune system's response to HIV is bumping around in a dark room," says Fauci. "It's an extraordinary virus. We are still struggling with trying to understand just what it is that can and will protect people."

"It wasn't an easy decision. But it was a decision based on a lot of good scientific advice from people," he adds.

That advice was simply this: Gp120 may work in the bloodstream but it won't work inside the cell. If the HIV virus gets past gp120 in the blood, the cells are sure to be infected. In a letter to Science magazine, more than 50 doctors and researchers said, in their opinion, gp120 does not induce immune responses of significant potency to be an effective vaccine.

But Francis insists gp120 has already shown too much promise to be discarded now: "If you have a tool that could potentially stop HIV in its tracks and prevent the HIV epidemic around the world, that's not something I can sit back and just walk away from. That's something that has to be moved forward."

But gp120 wasn't moving anywhere. In terms of vaccines, a death sentence from the NIH is almost always fatal. Still, Francis wouldn't give up.

Based on the initial NIH trials, a new and improved version of the vaccine was developed. Then Francis had to find the money for a new set of trials. That would cost millions of dollars and he had only one place left to get it: Wall Street.

Francis gambled everything to start a new biotech company called VaxGen. Investors put up more than $100 million for "pure science and a little bit of faith."

"At that point, we truly had money," says Francis. "We were not begging for any other support from a government organization or from Genentech or from any other private sector. We had our own money. We'd hire our own people, find our own offices and just move ahead."

But Francis needed something that money couldn't buy: nearly 8,000 volunteers for his study. And not just anyone would do. The volunteers had to be HIV negative but still at risk of getting AIDS. You might expect the gay community would be eager to help. But recruiting volunteers turned about to be another major obstacle to gp120.

Tim Burton, a sexually active gay man, is one person who decided to place his trust in Francis' project. It is a heavy commitment, without pay. Burton will be vacinated every six months for three and a half years. He must also attend regular counseling sessions.

Burton says he didn't realize how different he would feel until after that very first shot. "I had said I was always going to do something if I could. If I had a chance, I would take it," says Burton. "And so here was this chance, and I took it. And I didn't realize until after I got the vaccination that I had just taken this chance. And so it was, like, 'Wow, I'd just done something,' and so that made me feel really good."

Gp120 is 100 percent synthetic - there's no actual virus involved - so it's considered harmless to humans. Not all of the volunteers are given the vaccine. Since it's a double blind study, two out of three get gp120; the rest, a placebo. And not even Francis knows who has recieved what until the trial is over.

"We have an independent committee that does have access to the - to the code of who will receive a vaccine and who will receive a placebo," explains Francis. "And they independently, private from us, isolated in privacy, sworn to secrecy, review the data every six months."

The results of the trial will not be known until the fall of 2001 at the earliest. For the FDA to license the vaccine, it must be shown to prevent HIV from occurring in at least 30 percent of all recipients.

If 30 percent doesn't sound like much protection, Francis says think again: "Thirty percent protection for a 100 percent fatal disease is that 30 percent of those people don't die."

But Francis hopes to some day eradicate AIDS in the same way he did small pox. And if gp120 fails, he will continue his search. "Science is a pursuit of the truth. Science is - is discovery," says Francis. "And negative answers are still steps up that ladder to understanding."

  • CBSNews.com staff CBSNews.com staff

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