SAN FRANCISCO, JUNE 1 -- A vaccine has been developed that protected two chimpanzees from the virus that causes AIDS in humans, a biotechnology company announced today.

Officials of Genentech Inc., the South San Francisco company that sponsored the research, warned against premature optimism for the vaccine, which they hope to begin testing in humans this summer.

"We have fairly high hopes for this, but it will take years to develop anything that could protect humans from AIDS," said Jack Murphy, Genentech spokesman. "This, right now, is more of a scientific development and certainly not a breakthrough."

The U.S. Food and Drug Administration must approve the vaccine for testing on humans before further research can begin, Genentech said.

Phillip W. Berman of Genentech and Jorg Eichberg of the Southwest Biomedical Research Center of San Antonio developed the Genentech vaccine.

In the experiment, two chimpanzees immunized with the experimental vaccine and then injected with the HIV virus remained healthy six months afterward. An unvaccinated chimp became infected within seven weeks, the researchers said.

The research is to be published in the British medical journal Nature. Genentech got permission from the journal to announce the findings early so it could be reported at the company's upcoming annual shareholders' meeting.

The Genentech vaccine is among several being developed in hopes of finding a way to protect people from contracting acquired immune deficiency syndrome, which attacks the body's immune system, leaving its victims vulnerable to deadly cancers and ailments. More than 80,000 Americans have died from AIDS since it was first reported in the early 1980s.

The Genentech vaccine is genetically engineered as are two other vaccines that have been approved by the FDA for human testing in people infected with the human immunodeficiency virus, or HIV, the virus that causes AIDS.

One of the vaccines, approved for testing in August 1987, was developed by MicroGeneSys Inc. of West Haven, Conn. The second, developed by Bristol-Myers-Squibb Co., of New York, was approved for human trials in November 1987.

"The hardest part about developing these vaccines is they're very specific and work against only one type of virus," Murphy said.

Eventually, Murphy added, a vaccine must be developed that protects against all strains of the disease.