This hotly disputed question will only burn brighter as more biological evidence surfaces to suggest a link. But a definitive answer might take years. Meanwhile, the Centers for Disease Control and Prevention is sitting on a multi-million-dollar database - paid for by you and me - that could probably resolve this contretemps within weeks.
They have the data. We paid for the data. Yet we cannot see the data. The information is kept under lock and key within the massive health agency -- as jealously guarded as nuclear secrets.
The CDC tells us that they have looked at the data exhaustively and found "no evidence of harm." They implied that their own scientists are perfectly capable of analyzing the data, thank you very much, and outside researchers cannot be trusted to independently verify their analyses, nor to protect the confidentiality of patients whose numbers they would be crunching.
But, as any high school student can tell you, the replication of a study is the hallmark of all good science. Without access to the raw data originally used by the CDC researchers, it is impossible to verify their work. All we can do is trust that they got it right.
The CDC, which has budgeted nearly $200 million to operate the Vaccine Safety Datalink, spent four years analyzing data from children who received varying amounts of thimerosal in their vaccines. The study went through five different permutations before being published in November, 2003. Early study "generations," which were never meant to see the light of day, showed highly elevated, statistically significant increased risks for autism and other disorders among the kids receiving the most mercury.
But by the time the study was published, most of these associations had somehow disappeared entirely.
Only two outside researchers, Mark and David Geier, have managed to gain access to the raw CDC data. They faced daunting hurdles to get into the CDC computer center, and nearly crippling software malfunctions once they were inside. But among the data they did manage to mine, they reportedly found highly elevated risks for autism among children in the highest mercury exposure group.
So we now have two extremely different interpretations of the same data. It is way past time that the CDC allow a third team - outside researchers completely acceptable to all parties involved in this dispute - into the database to conduct any analyses they see fit. (Patients names are removed from the data, making it exceedingly hard for researchers to identify anyone, even if they desired, which is extremely unlikely in itself).
It sounds reasonable, it sounds nice. But don't hold your breath. The CDC is hardly issuing engraved invitations to come trawl its mainframes, despite a harshly written report earlier this year from the Institute of Medicine. The IOM complained of CDC foot dragging, and even insolence, on this matter, and suggested that vaccine officials at the health agency seek "legal counsel." Why? Because the original datasets of children used by the government have, as they say, gone missing. (Actually, the official explanation was that they "were not archived in a standard fashion.") The intentional loss or destruction of taxpayer funded data or datasets is a violation of the Federal Data Quality Act. It is a felony, and someone could go to jail for it.
Meanwhile, the data just sit there. Our data, not theirs. CDC officials insist they have an "open mind" on this issue, and that thimerosal has not been ruled out as a possible cause of autism and other disorders. But they also insist that the vaccine safety database yielded no evidence of harm.
If that is true, then why are they so reluctant to let someone else in to verify this claim? I cannot answer that question, because the CDC is not talking to me. But I do know that people with nothing to hide are unencumbered by doubts of what others will find if they rifle through their closet.
If the data can prove that injecting a known neurotoxin into infants at levels up to 125 times over federal safety limits was a safe and sane thing to do, then why isn't the CDC having an open house for all researchers worth their salt to come on down and have a look-see for themselves?
Without access to the raw data, parents who support the thimerosal theory - and their allies in Congress, academia and law - are falling back on other recent studies that show a possible link between mercury and autism. They may not have the epidemiology on their side, yet, but the mounting evidence emerging from the fields of biology and toxicology is becoming too urgent to ignore. Recent published studies have shown:
+ Autistic children retain mercury at much higher rates than non-autistic kids.
+ Autistic children lack certain sulfur-based proteins that bind to heavy metals and remove them from the body.
+ Autistic children have a dysfunctional immune profile generally consistent with mercury toxicity.
+ The rate of increase in reported autism cases peaked between 1987 and 1992, the same years that new mercury-containing vaccines were added to the U.S. schedule.
+ Mice with autoimmune disorders react horrifically to mercury exposure from vaccines, whereas typical mice of the same species do not.
+ In primates, mercury from vaccines was more likely to become trapped in the brain than mercury from fish.
+ Children who live near mercury spewing power plants have an elevated risk of developing autism.
These are all intriguing, to be sure. But what we really need is to get our hands on the raw CDC data - our data.
David Kirby is (St. Martin's Press) www.evidenceofharm.com