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From the StarTribune, 2/25/03

Minnesota AIDS experts who helped test an experimental vaccine say they are disappointed, but not surprised, that the vaccine didn't seem to work in a three-year study of more than 5,000 volunteers.

And they are skeptical about one of the findings disclosed this week: that blacks and Asians seemed to do better on the vaccine, known as AidsVax, than whites.

"You have to be very cautious," said Dr. Frank Rhame, an AIDS specialist at Minneapolis' Abbott Northwestern Hospital who led one of two AidsVax test sites in Minnesota. "Is there some reason that vaccines should work in African Americans and not in whites? I haven't seen an explanation."

Overall, "the effect of the vaccine was minimal," the vaccine's manufacturer, VaxGen Inc., said Monday. Its study -- the largest ever on an AIDS vaccine -- found no "significant reduction of HIV infection within the study population as a whole."

Yet two small groups did show a "statistically significant" drop in HIV infection, according to the company. After receiving the vaccine, black volunteers had 78 percent fewer infections, and non-Hispanic minorities had 67 percent fewer infections, than a control group, the study found. Subjects in the two groups also had higher levels of AIDS antibodies in their bloodstream than white subjects.

Experts say the racial gap may be a statistical fluke. At best, Rhame said, it calls for more study.

Dr. Keith Henry, who tested the vaccine at Hennepin County Medical Center, said "it's plausible" that genetic differences may explain the gap. But the evidence was marginal, and the overall results were "totally unimpressive," he said.

VaxGen, based in Brisbane, Calif., has spent $200 million developing the vaccine and said it hopes to someday help slow the spread of AIDS. On Monday, its stock price fell $6.16 a share, or 47 percent, to close at $6.86.

Henry said scientists were "lukewarm at best" about the vaccine all along. But he and others say it was worth testing because even a modest vaccine could help stem the epidemic.

"The major message to me is, there's not going to be any quick answer other than safe behavior," he said.