AIDS Vaccine May Reduce Rate of Infection: Greater Efficacy in Nonwhites
Walsh, Nancy, Clinical Psychiatry News
ATLANTA -- The available results of the phase III AIDSVAX trial suggesting a lack of overall efficacy are "very preliminary" and any decision on further clinical trials with this vaccine would be premature at this time, experts agreed at a meeting of the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices.
An initial analysis of the trial data, announced by the manufacturer in late February, found a reduction in rate of infection of only 3.8% among the entire study sample. The company VaxGen Inc. of Brisbane, Calif., had hoped for 30% efficacy.
Although overall efficacy was not seen, evaluation of secondary end points of reduction of viremia and change in CD4 counts remains to be done, said Lance K. Gordon, chief executive officer of VaxGen.
Overall, among those receiving the vaccine 5.7% became infected, compared with 5.8% of those given placebo.
Among black, Asian, and other minorities, the rate of infection was 3.7% in those who were vaccinated, compared with 9.9% in those receiving placebo, a small but statistically significant difference. Among whites and Hispanics, 6% of those given the vaccine became infected, as did 5.4% of those receiving placebo.
The finding that certain ethnicities appeared to benefit was unexpected, but the numbers in the trial were small, with only 314 blacks and 77 Asians of the 5,400 total volunteers. …