Why did the most important trial to have been conducted on anthrax vaccine safety (by CDC between 2002 and 2007, with 1564 civilian subjects) only publish an interim report, and never discussed the 229 serious adverse events reported in trial participants? The trial tested serologic efficacy also. The investigators published partial data in JAMA on October 1, 2008, but only for the first 7 months of a 43 month trial, and only for 2/3 of the subjects.
The 2008 data were used to reduce the initial vaccine course from 6 to 5 doses, and to switch from subcutaneous to intramuscular doses. Within 4 weeks of publication, DHHS bought 14 million more doses of vaccine, in addition to about 25 million already stockpiled, and CDC's Advisory Committee on Immunization Practices (ACIP) approved anthrax vaccine for first responders. An earlier 2000 ACIP report had recommended against use in groups for whom a risk-benefit calculation could not be made:
"Although groups initially considered for preexposure vaccination for bioterrorism preparedness included emergency first responders, federal responders, medical practitioners, and private citizens, vaccination of these groups is not recommended. Recommendations regarding preexposure vaccination should be based on a calculable risk assessment. At present, the target population for a bioterrorist release of B. anthracis cannot be predetermined, and the risk of exposure cannot be calculated. In addition, studies suggest an extremely low risk for exposure related to secondary aerosolization of previously settled B. anthracis spores (28,83). Because of these factors, preexposure vaccination for the above groups is not recommended. For the military and other select populations or for groups for which a calculable risk can be assessed, preexposure vaccination may be indicated."
Although the final CDC trial results, carefully collected during about 20 clinic visits for each subject, have not been released:
- a federal advisory committee voted in favor of testing the vaccine in children,
- an additional $1.25 billion worth of anthrax vaccine was purchased for the civilian stockpile 3 weeks ago (44.75 million doses),
- the decision to approve use of the vaccine in civilian first responders were all made without these data.
The real question is who gave DHHS its marching orders, and what did they get in return?
Congress ordered a civilian trial of anthrax vaccine in 1999, yet 12 years later we have thousands of injured people, but the CDC data on anthrax vaccine safety has not been shared with the public, though it was publicly funded.
Do the data so challenge government policy that they have to be hidden? How could any policymaker, knowing this cache of data exists, not demand it before buying $1.25 B worth of vaccine, or proposing vaccine for first responders, and then children?
The principal investigator of this trial for CDC is veterinarian Jennifer Wright. Jennifer briefed the ACIP (with significant omissions), leading to their vote in 2008 in favor of first responder vaccinations. Before Jennifer, veterinarian Nina Marano at CDC was in charge. It seems relevant that veterinarians supervised a human clinical trial; MDs have different ethical obligations than veterinarians.
The following quote from the journal Nature is about the controversial early release last week of data from a malaria vaccine trial. It makes clear that the release of the very early CDC anthrax vaccine data was odd, and failure to publish the final data unacceptable, for a trial that ended 4 years ago. CDC would have us accept the cherry-picked preliminary data as the last word on this trial. We must demand the real thing.
"Some researchers question whether the results should have been published before all the data were available; full results are expected in 2014. Interim trial data are usually reported only to regulatory authorities, and clinical trials published only once all the data are in, noted Nicholas White, a malaria expert at Mahidol University in Bangkok, in an editorial3 accompanying the interim results. "There does not seem to be a clear scientific reason why this trial has been reported with less than half the efficacy results available," he wrote."
1 comment:
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