Surprisingly enough, there are still people promoting the idea that the rise in autism diagnoses observed over the last decades was caused by thimerosal in vaccines. The original argument was this–vaccines were added to the vaccine schedule in the 1990’s and with them the infant exposure to thimerosal increased. Concurrent with this rise in infant thimerosal exposure was a rise in autism diagnoses. Add to this a poorly concocted argument that autism resembles mercury intoxication and you have the basis for the mercury hypothesis.
Thimerosal was phased out of infant vaccines over 10 years ago. Thus, if the thimerosal hypothesis were true, reported autism rates should be declining by now. As far back as 2005 David Kirby (whose book “Evidence of Harm” played a major role in promoting the mercury hypothesis) acknowledged this point in a statement
If the total number of 3-5 year olds in the California DDS system has not declined by 2007, that would deal a severe blow to the autism-thimerosal hypothesis.
To be specific, let’s use the same method that David Kirby and others used to claim a thimerosal induced autism epidemic in the 1990’s (namely the California DDS client count–which not a good method, by the way). Autism “rates” have gone up by over 150% since thimerosal was phased out of infant vaccines. The age 3-5 bracket had about 4000 children in 2003 and is currently over 10,000.
So we have more kids in California receiving services under the autism label than when thimerosal was in vaccines.
This is but one in a huge list of reasons why the thimerosal hypothesis doesn’t work.
But let’s go back in time a bit. Not so long ago one would hear proposals that we go back to the vaccine schedule of the early 1980’s when, it is claimed, the autism rate was 1 in 10,000. Fewer vaccines, less thimerosal, less autism. So goes the logic.
Generation Rescue, in fact, used to recommend the 1983 schedule as one of their alternative schedules
Turn back the clock
Comment: This is the schedule from 1983. If it worked for kids then, why doesn’t it work for kids now?”
Does it make sense to go back to the 1983 schedule? No. Why? OK a lot of reasons, but let’s focus on the fact that infants were exposed to more thimerosal in the 1980’s than today. Infant vaccines have no or only trace amounts of thimerosal. So if thimerosal were the (or even a single) primary cause of autism risk, we would see autism rates lower today. To not only 1990’s levels, but to something like 1980’s reported levels. Assuming that the reported rates in the 1980’s were an accurate count of how many autistics there were then (a bad assumption but it’s the one they use).
To recap–Infant thimerosal exposure from vaccines peaked at nearly 200 micrograms in the 1990’s, up from about 100 micrograms in the 1980’s and is now less than 10 micrograms. And autism rates have not declined at all. Much less to 1980’s levels.
Once anyone says this the instant answer is that there is still thimerosal in some influenza vaccines. This, they say, is why autism rates have not declined. (note that thimerosal containing vaccines, including influenza vaccines, are banned in California for infants and pregnant women…and autism “rates” have continued to climb here).
For completeness sake, let’s consider a kid who gets the maximum exposure to thimerosal from vaccines. I.e. a non California kid. A kid who turns 6 months (the earliest age they will give a flu vaccine to a kid) during the flu season. That kid will get 2 vaccines in the first year (6 and 7 months) then another influenza vaccine each year thereafter. Each with 25 micrograms of mercury from thimerosal. How does the thimerosal exposure compare to the 1983 schedule? Take a look for yourself (exposures in micrograms of mercury from thimerosal):
|1983 schedule||2013 schedule|
|Total by 1 year||75||50|
|Total by 2 years||100||75|
|Total by 3 years||100||100|
So by age 3, the exposures are the same. Except that the kid of today gets the thimerosal later and more spread out over time. As an aside–most people who talk about the rise in thimerosal exposure during the 1990’s neglect to point out that the cumulative exposure in the 1980’s was already 100 micrograms. I.e. the “safe” level was significant.
If thimerosal were the driving force behind the rise in autism diagnoses, we should be back to 1983 levels, misrepresented by those claiming an epidemic as 1 in 10,000. Instead we are at 1-2%. The “rates” didn’t go down.
By this point the proponents of thimerosal are basically screaming, “you are forgetting the vaccines recommended to pregnant women!” No, I just put that off until now. Sure, the influenza vaccine is recommended for pregnant women, but as the CDC notes:
Prior to 2009, influenza vaccination levels among pregnant women were generally low (~15%) (5,9).
So, from about 2000 to 2009 there wasn’t a big increase (or even a large part of the population) getting influenza vaccines while pregnant, nor were their children getting exposures higher than those in the 1983 schedule.
Take a look at that graph for California administrative autism prevalence again. Between 2002 (after the drawdown of thimerosal in vaccines) and 2012 the autism count doubled. Thimerosal exposure was down. A lot. Below 1990’s “epidemic” levels. Back to the 1983 “worked for kids then” levels. But autism “rates” continue to climb.
The people still pushing the idea that thimerosal is a (or even the) primary cause of autism are not unintelligent. We are talking about college educated people. Ivy league schools. A former journalist, an intellectual property expert and more. There is no math above. It’s all quite simple and straightforward. It uses the exact same logic and methodology they used to promote the idea that mercury causes autism. This is where intellectual honesty and basic integrity should kick in and get people to suck it up, admit their mistakes and start repairing the harm they have caused.
I’m not holding my breath.
By Matt Carey