Vaccination News Home Page                                            subscribe Vaccination NewsLetter

http://www.bayarea.com/mld/mercurynews/business/5283800.htm

Posted on Fri, Feb. 28, 2003

Biotech trouble

VaxGen stands by its vaccine

STOCK PRICE FALLS ON NEW QUESTIONS OVER DISAPPOINTING VACCINE RESULTS

By Paul Jacobs

Mercury News

VaxGen executives stood firm Thursday under mounting criticism from scientists who questioned the way the biotech company analyzed its results finding its AIDS vaccine may protect blacks and Asians more than others.

One academic consultant to VaxGen, while not ruling out that there may be racial and ethnic differences in response to the vaccine, said Thursday that the company should have corrected its findings. A corrected analysis suggests that the vaccine's protective effect in minority volunteers could be much smaller than the company's estimate and possibly non-existent, he said.

“It could be a real effect, or it could be a fluke,” said Steven G. Self, a biostatistician of the Fred Hutchinson Cancer Research Center and University of Washington in Seattle. “It's interesting enough to look at and find out which it is.”

But he said it was “premature” for the company to take the results to the Food and Drug Administration in an effort to license the vaccine for use by specific ethnic or racial groups.

The Brisbane company, responding to criticisms published in Science magazine and elsewhere, stood by its statistics Thursday: “The results VaxGen reported on Monday remain accurate as stated, and the analysis continues.”

Earlier this week, VaxGen announced that the first large test of its AIDSVAX vaccine in more than 5,000 volunteers, mostly gay men, showed that the vaccine failed overall to offer protection against the human immunodeficiency virus or HIV, which causes AIDS. Altogether, 5.7 percent of those who received the vaccine became infected over the course of three years compared to 5.8 percent of those who got dummy shots, or placebos. The difference was not statistically significant.

But the company reported that the vaccine showed a significant reduction in infections among certain vaccinated groups -- a 67 percent lower rate among non-Hispanic minorities, and 78 percent lower among blacks.

Four AIDS advocacy groups issued a statement accusing the company of playing “the numbers game” to serve “the commercial interests of the company.” Central to their argument are the small numbers of non-Hispanic minorities in the study -- just 498 -- and the even smaller number of HIV infections, just 13 among 314 black participants and four among Asians.

Self and other statisticians say that the small numbers limit what they call the “power,” or the reliability, of the findings.

Among the blacks who were infected were four women, who all received placebos and not the vaccine -- from a Chicago test site.

That raises the possibility that at least some of the apparent effectiveness of the vaccine in minorities is the result of gender and not race, says Neil J. Risch, a professor of genetics at Stanford University.

“My opinion is they did not study enough African-Americans,” he said. The results don't prove that there was an effect, he said, but they do suggest the need for further study.

For their part, shareholders continued to demonstrate their disappointment. VaxGen shares were battered Thursday for the fourth day in a row, closing at $4.25, down 12 percent for the day and 67 percent for the week.

——————————————————————
Contact Paul Jacobs at pjacobs@sjmercury.com or (530) 756-0236.

Vaccination News Home Page

ALL INFORMATION, DATA, AND MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR GENERAL INFORMATION PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE KNOWLEDGE OR OPINIONS OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED AS PROVIDING MEDICAL OR LEGAL ADVICE.  THE DECISION WHETHER OR NOT TO VACCINATE IS AN IMPORTANT AND COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN CONSULTATION WITH YOUR HEALTH CARE PROVIDER.