A possible AIDS vaccine that appears more promising in chimpanzees and better designed for humans than other vaccines, will now be tested in humans, researchers said.

Government-affiliated AIDS researchers and officials from Immuno-U.S. Inc. of Rochester, Mich., announced Tuesday the Food and Drug Administration has approved testing of their jointly developed AIDS vaccine in about 60 healthy people.The genetically engineered vaccine, called IMMUNO-Ag, is the sixth AIDS vaccine authorized by the FDA for human testing but is the first to be developed in conjunction with the government. Tests of the other AIDS vaccines have not yet produced any conclusive results.

If the new vaccine encounters no roadblocks in testing, researchers estimated it would be at least five to 10 years before it could be generally available to the American public.

The laboratory-made protein the vaccine uses to spur an immune system response more closely mimics the natural AIDS protein, called gp160, than previous candidate vaccines, researchers said.

Dani Bolognesi, an AIDS vaccine expert at Duke University School of Medicine in Durham, N.C., said the new vaccine's gp160 protein is "without a doubt much more natural" than those used in other potential AIDS vaccines being tested in humans.