Our Best Shot? Researchers Race To Develop An Aids Vaccine, But Problems Loom

President Clinton’s call for a national effort to develop an AIDS vaccine within 10 years echoed President John F. Kennedy’s challenge for a race to the moon nearly four decades ago.

But the medical quest is plagued with problems the space program never knew, problems that make reaching Clinton’s deadline exceedingly difficult.

The AIDS vaccine researchers lack resources the moon race had and face ethical quandaries the space scientists never did. Also, with the recent success of powerful AIDS drugs, public support for AIDS vaccine research is unlikely to match the support for the 1960s space program. The disease increasingly isn’t costing American lives - or pride.

“It is a serious possibility that we may never develop a vaccine for HIV,” the virus that causes AIDS, said Robert Gallo, one of the discoverers of the virus and the director of the Institute on Human Virology in Baltimore. “We believe we will, but we are not sure.”

Public health experts warn that declaring something important does not guarantee the problem will be solved. President Richard Nixon’s War on Cancer, for example, was launched 26 years ago, and no end is in sight.

Mark Grayson, a spokesman at the Pharmaceuticals Research and Manufacturers Association, a group of many of the country’s major companies, called Clinton’s goal laudable. “But certainly there is a lot more to it than saying, it’s going to be done,” he said. “There are no additional resources.”

Early vaccine research has revealed several difficulties. The AIDS virus mutates rapidly, making it a difficult target. Different strains of the virus exist in different countries, and scientists don’t know whether a vaccine that is effective against one strain would be effective against others. And since no one has ever recovered from an AIDS infection, scientists don’t know how exactly to program the immune system to fight off the disease.

“In May 1997, there is no breakthrough, but a number of things are heading in the right direction,” said Anthony Fauci, the government’s top AIDS researcher, in a recent interview.

Worldwide, the AIDS epidemic is expanding relentlessly, mostly in the developing world. In 1995, scientists estimated that some 4.7 million people became infected, more than 95 percent of them in the developing world.

Clinton issued the call for a vaccine at a commencement speech Sunday at Morgan State University in Baltimore. He promised no extra money for the challenge, but he said the National Institutes of Health would create an AIDS vaccine research center that would centralize efforts to find a vaccine.

Currently, the federal government spends about $1.5 billion for AIDS research.

“He’s not putting any more money in it,” Philip Russell, professor of International Health at Johns Hopkins University in Baltimore, complained of Clinton. “The problem is not lack of research at NIH, the problem is lack of investment within the vaccine industry.”

When astronauts landed on the moon, he said: “It was the space industry that did it. We used the space industry to get to the moon; we should use the vaccine industry to get a vaccine.”

So far, the bulk of the AIDS research effort has been targeted at finding treatments for those already infected.

Those efforts bore fruit last year, when powerful drugs succeeded in suppressing the virus in many patients to the extent that it can no longer be detected. Scientists hope the drugs, which are keeping patients alive, can eventually cure them.

But pharmaceutical companies have shrunk from investing in vaccines the way they have invested in drug development.

“I’m not sure even a brilliant vaccine could be marketed,” said Gary Rose, treatment and research coordinator at AIDS Action Council in Washington, a leading advocacy group. “Companies will be too terrified about the risk.”

That risk comes in two forms: economic and legal.

Developing and testing an AIDS vaccine may be as expensive as developing the powerful AIDS drugs released last year. Vaccines may not provide companies with a similar return on their investment. Drugs may have to be taken regularly for life, whereas an effective vaccine can protect people for years with a single dose.

The legal risk is because of fears that even a highly effective AIDS vaccine might not protect everyone from disease or may even accidentally infect a healthy person.

Testing the vaccine will also likely involve the ethical quandary of conducting studies in the developing world, the only place the disease is spreading fast enough to see if vaccine candidates are any good.

“How do we make an experimental vaccine for testing in those regions for ultimate use in the U.S.?” asked Max Essex, director of the Harvard AIDS Institute.

Beyond all of this, is the scientific challenge.

“There are a lot of uncertainties about what’s going to work, how it’s going to work,” said Pat Fast, an AIDS researcher at the National Institutes of Health. “We need to look at a wide variety of vaccines and bring them along, since we don’t know how things are going to go.”

MEMO: This sidebar appeared with the story: VACCINES IN WORKS Several types of experimental AIDS vaccines are in various stages of development. They are:, Recombinant peptide vaccines. These are laboratory-made proteins similar to proteins from the envelope and inner core of HIV. When injected into a person, they stimulate the immune system to make antibodies against HIV. Live virus vaccines. These use a live virus, such as the vaccinia virus or the canary pox virus, which has been genetically engineered to include some genes from HIV. When injected into people, the virus integrates its genetic material into the person’s genes. Those infected cells start producing HIV proteins, which stimulate the immune system to make antibodies against HIV and key immune system cells known as killer t-lymphocytes, both of which can attack HIV. DNA vaccines. These are made out of “naked” laboratory-made genetic material identical to genetic material in HIV. When injected into people, the DNA enters muscle cells in the arm, which then start producing HIV proteins encoded by the DNA. The proteins stimulate the immune system to produce antibodies and killer t-lymphocytes. Live attenuated vaccines. These are made from whole live HIV that has been weakened so that the virus cannot cause disease. This is the same strategy used to make the highly effective oral polio vaccines. These vaccines stimulate both antibodies and killer t-lymphocytes.