The development of an AIDS vaccine to prevent infection in people free from the virus or to fight the full-blown disease in those with it is only a matter of "fine tuning" existing techniques, Dr. Jonas Salk said Monday.

Salk, who pioneered the world-famous Salk vaccine against polio in 1955, told doctors attending the American Federation for Clinical Research convention that studies being conducted to develop an AIDS vaccine are progressing, but he declined to predict a time frame for final success.Salk said a study on monkeys infected with SIV, the simian version of HIV, the human immunodeficiency virus thought to be the precursor to AIDS, has shown promising results. Of 35 monkeys given various dosages of a vaccination containing the live SIV virus, 30 of them were able to avoid contracting the full-blown disease, at least to date, he said.

Another study using a non-live version of the HIV virus in humans had less promising results, but Salk said he believes his "low-technology" approach, as opposed to the "high-tech" biotechnology solution to AIDS being sought by others, will be successful.

"The prospects for the development for a vaccine that would prevent infection and-or disease is now a matter of fine tuning," he said.

By fine tuning, Salk said he means the dosage levels, length of treatment and other factors must still be worked out for using the live HIV virus to develop an effective AIDS vaccine.

To date, no such vaccine has been given to people without the HIV virus, in part due to the risk of exposing uninfected populations to the possibility of a fatal disease for which there is no cure.