New findings dim hope for vaccine against AIDS
LOS ANGELES - A secondary analysis of data from the Thai AIDS vaccine trial - announced last month to much acclaim - suggests that the vaccine might provide some protection against the virus, but that the results are not statistically significant: They could have resulted merely from chance.
Initial results from the trial involving more than 16,000 people had indicated that the vaccine reduced infections by about 31 percent. But the new analysis, which was part of the trial protocol, showed that it seemed to reduce infections by only 26 percent.
Partial results from the secondary analysis have been circulating for a couple of weeks, but the full results were published online in The New England Journal of Medicine and announced yesterday at an AIDS vaccine conference in Paris.
In an editorial accompanying the journal paper, Dr. Raphael Dolin of the Beth Israel Deaconess Medical Center in Boston said the overall findings are nonetheless “of potentially great importance to the field of HIV research’’ because they may yield information about the kinds of immune responses necessary to protect against the virus.
But Dr. Otto Yang, an immunologist at Geffen School of Medicine at the University of California, Los Angeles, cautioned that “the results are weak enough that we need to be very careful about assigning too much optimism to them. . . . It seems not so likely that the vaccine really did what it was intended to do.’’
The trial, sponsored largely by the National Institute of Allergy and Infectious Diseases, combined two vaccines, each of which had individually proved ineffective in previous trials.
The original analysis excluded seven patients who were found to have HIV infections when the study began. The new analysis included all patients who were originally enrolled in the trial, producing the weaker results.
