Federal health officials yesterday approved human tests of a candidate AIDS vaccine, the sixth such experimental vaccine to be sanctioned for human testing by the Food and Drug Administration.

The vaccine, developed by researchers at the Austrian biotechnology copmany Immuno A.G., will be tested on 60 volunteers at five federal AIDS vaccine evaluation units.

Like all other experimental AIDS vaccines, the Immuno candidate attempts to trick the body's immune response into launching an anti-AIDS attack with an injection of what looks like the AIDS virus but is harmless. In tests done by the company, the vaccine protected one chimpanzee from 100 infectious doses of the HIV virus over a three-year period. A second chimp was protected by the vaccine for nine months.

In the human trials, which will be conducted on volunteers not infected with the HIV virus, researchers will look primarily to see whether the vaccine is safe and to evaluate what kind of response from the body's immune system the vaccine can induce. The volunteers will not be challenged, as the chimps were, with a real dose of HIV.

The company said that if the vaccine passes the early tests it will take between five and 10 years to determine whether it is of any use in humans.