Good news on AIDS.

Two recent discoveries offer new hope in the battle against AIDS (acquired immune deficiency syndrome), a disease that has killed about 300,000 people in the United States since 1982.

First, a blood-bank worker in Australia recently discovered that several people are healthy more than 14 years after being infected with HIV (human immuno-deficiency virus), the virus that causes AIDS. The group received HIV-infected blood transfusions before tests were available to screen for the virus.

Scientists say these people carry a genetically "defective" strain of HIV. This strain reproduces more slowly than other strains and may not make people sick. If that's the case, the defective strain might be used to make a vaccine: Healthy people would be exposed to the defective virus so that they could produce antibodies, chemicals that would protect them from more dangerous HIV strains. One researcher says the vaccine may be available for human tests in as few as two years.

In another study, a drug called PMPA stopped SIV (simian immuno-deficiency virus) from infecting 25 macaque monkeys. Che-Chung Tsai, a researcher who helped test the new drug, says SIV and HIV are very similar. So a drug that works against the monkey virus should help people too.

Studies to test PMPA's safety and effectiveness in humans may start in early 1996, Tsai says.