WASHINGTON -- Despite disappointing data released atOctober's conference of the National Institute of Allergy andInfectious Diseases (NIAID) on AIDS, vaccines might still beready for large-scale testing within a year, Anthony Fauci, headof NIAID, told BioWorld. But a commercial vaccine is probablystill years away.

Although vaccines had neutralized the virus in vitro, in Phase Iand II trials they had failed -- with one small exception --against "street" strains of HIV. "Right now the indication thatwe are getting from the preliminary studies is that theresponse we see is too narrow and (weak)," Fauci toldBioWorld.

A key to vaccine design is to find the antibody and level oftiter that prevents disease. This is usually a fairly simplematter of developing a vaccine that stimulates the sameantibodies the illness does. But in HIV, "it is still unclear whatconstitutes protective immunity, so the end point is still indoubt," Fauci said.

Unlike virtually every other virus, this "very unusual micro-organism ... does not, to our knowledge, elicit in the naturalstate the type of immunity that can completely suppressprogression of the viral disease," he said. Therefore, it isnecessary to be cautious about deciding when to go into a full-scale efficacy trial.

It could take a cocktail of antibodies expressed on a vector,together possibly with the transmembrane region, to elicit abroader range of antibodies that are truly neutralizing andcytotoxically responsive, said Fauci. "Another approach is to usemore potent adjuvants," he said. But don't look for acommercial vaccine for "at least several years."

As for therapeutic alternatives, "they are not adequate in thelong run," he told BioWorld. "They tend to have substantialtoxicity, which limits their usefulness."

Biotechnology potentially has more to offer. "Conceptually, (itsproducts) can be very exciting," Fauci said, referring toprotease inhibitors, integrase, antisense, ribozymes specificallyand targeted approaches generally. "But you don't want to holdout false hopes until there is more solid data I There is a largeleap from conception to reality.

"People are cautiously optimistic about protease inhibitors," hesaid. "They are being tested right now in early trials."

HIV research and biotechnology have developed a synergisticrelationship, he pointed out. Biotechnology begat targeteddrugs, and HIV research has wrought technical improvementsin PCR, diagnostic tests and recombinant work for vaccines.

Meanwhile, funding for HIV research is quite healthy at NIH.The Clinton administration has boosted funds for fiscal 1994 to$1.3 billion (12 percent of the agency's budget). "In science,you never have enough money and could always use more, butI think AIDS is doing well," said Fauci.

He is optimistic that basic research will receive its due. "Thereis always the tendency to push one to do more appliedresearch. We in the scientific community have the strongsupport of (NIH Director Harold) Varmus, who is verycommitted to basic research ... (which) is where the enduringanswers are going to come from."

Fauci does not expect to see changes in the virus' character.Among viruses with very long latency, "major changes invirulence take place over decades and even centuries," he said.

And in the U.S., HIV is still spreading for the most part withinconfined areas connected to a risk group: individuals with ahigh degree of IV drug use and those who have high levels ofsexually transmitted disease because of a typical type of sexualconduct. "We are not seeing it randomly and homogeneouslyspread through the population in a heterosexual manner," hesaid.

-- David C. Holzman Washington Editor

(c) 1997 American Health Consultants. All rights reserved.