obody thinks the struggle against AIDS will be easy, but the great difficulties still lying ahead were underscored this week by two unrelated developments. The makers of the first vaccine to be subjected to a large clinical trial had to admit that it didn't seem to work for most people, although they found glimmers of hope that it might protect black and Asian recipients. And the manufacturer of a breakthrough AIDS drug that might control the disease when standard drugs have failed delivered the bad news that a year's supply will cost $20,000 in Europe, and presumably even more in the United States. That makes it questionable how many people infected with the AIDS virus will have the insurance or personal wealth to afford it.

The failure of the vaccine, manufactured by VaxGen, was not wholly unexpected. Leading AIDS scientists had predicted the approach would fail, and the company that invented the vaccine deemed it unworthy of clinical trials. As it turned out, the vaccine was no more effective than a placebo. The company stressed that the vaccine seemed to protect a subgroup of black, Asian and other minority heritages, but the numbers were too small to generate much confidence in the findings. Further analysis is warranted to determine if there really are racial differences in response. But an effective vaccine is probably years away.

Meanwhile, a new drug called Fuzeon, which is under review by the Food and Drug Administration, represents a completely new method of suppressing the AIDS virus. Unlike existing drugs, which attack the virus once it has entered a cell, Fuzeon blocks the virus before it can enter, making it effective where other drugs have lost their punch. The chief drawback is the high price announced by Roche this week — a result, the company said, of high development costs and a manufacturing process far more complicated than that for any other AIDS drug. Government and private health plans will need to bargain hard lest the price make it difficult for patients to gain access to a life-saving treatment.