Another Study Shows No Link Between Autism and Thimerosal

No increased risk for any autism subtypes
No increased risk associated with prenatal exposure

A new study published today in the journal “Pediatrics” indicated that there was no increased risk of Autism Spectrum Disorder associated with receipt of thimerosal-containing vaccines. The study also found no increased risk for any of the subtypes of Autism Spectrum Disorder, including ASD with regression.  In addition, it found no increased risk of Autism Spectrum Disorder associated with prenatal exposure to thimerosal.

A case-control study was conducted in 3 managed care organizations of 256 children with ASD and 752 controls, matched by age and gender. Exposure to thimerosal was determined by electronic immunization registries, medical charts and parent interviews.

This study confirms previous research, which has not revealed an increased risk of autism associated with receipt of thimerosal containing vaccines. It adds to the body of knowledge by reporting that prenatal exposure to thimerosal is not associated with autism. It also looked specifically at subtypes of autism, including autism with regression, again finding no association with thimerosal exposure.

No significant differences in exposure effects were found between boys and girls for any of the ASD outcomes; there was no evidence that higher prenatal exposure exacerbated the effects of post-natal exposure; and there was no evidence that concurrent ethylmercury exposure was associated with ASD. In addition, there was no substantive difference in the association between thimerosal exposure and risk for ASD among children with an older sibling with autism and those without an older sibling with autism.

“In a way, it’d be great if thimerosal in infant vaccines was the culprit because the U.S. has already removed thimerosal from them” said Dr. Sharon Humiston, a pediatrician and FAAP, former member of the National Vaccine Advisory Committee (NVAC) and member of the Autism Science Foundation Science Advisory Board.  “Because we have not found the root causes of autism, we need to keep funding the research that will help us find them.  Because the resources to find what really does cause autism are scarce – money, scientists, and time – we urgently need to focus these resources on avenues that appear to be fruitful.  The vaccine hypothesis just has not yielded answers that help my autistic son or my typically developing daughter who may want to have children of her own one day.”

Pediatrics, September 13, 2010: Prenatal and Infant Exposure toThimerosal From Vaccines and Immunoglobulins and Risk of Autism

PBS Frontline’s “The Vaccine War”, Worth Watching!

We highly recommend PBS’s “The Vaccine War” which aired last night on PBS. In a rare display of tv news common sense, one side is simply declared to be wrong. The science is very clear; vaccines do not cause autism and it’s time to move on from this well debunked myth and find out what does.

The show features interviews with ASF Board Member Dr. Paul Offit, Dr. Arthur Caplan, Dr. Anthony Fauci, Dr. Cynthia Cristofani, Dr. Anders Hviid & Dr. Eric Fombonne, as well as with actress Jenny McCarthy and JB Handley of Generation Rescue. 
“Scientifically, I think the matter is settled,” says Anders Hviid, an epidemiologist at the Statens Serum Institut in Denmark. In one of the largest and most comprehensive epidemiological studies available, Hviid and colleagues analyzed data on more than a half million children and found no link between the MMR “triple shot” for measles, mumps and rubella and an increased rate of autism — a link that’s been strongly asserted for years by anti-vaccine activists. Similar epidemiological studies in Denmark also failed to reveal a link between the mercury preservative thimerosal and autism. In fact, around the world, peer-reviewed epidemiological studies have found no link between autism and either the MMR shot or thimerosal.
You can watch the full episode online or check local listings, as we’re told by PBS that the show will air multiple times this week.  

View scientific studies regarding autism and vaccines here

Media Roundup: Vaccine Court Thimerosal Rulings

ABC World News Tonight  (includes interview with ASF Board Member Dr. Paul Offit)

USA Today

New York Times

National Public Radio


LA Times

CBS Evening News (includes interview with ASF President Alison Singer)

View scientific studies regarding autism and vaccines here

Read a summary of the King case here (from Kathleen Seidel at

Misplaced Fear: Resolving the Fear Around Vaccines and Autism

By Lydia McCoy
Executive Director of the Colorado Children’s Immunization Coalition.

Thimerosal and the MMR vaccine do not cause autism.


There I said it.


I know parents are scared. I know parents just want to do what is best for their children. I also know that vaccines are not the thing to fear, it is disease that should be feared.


Measles is not something that any child needs to endure. The MMR vaccine has been incredibly powerful in protecting children and our entire community.

“The measles vaccination has resulted in a decrease in reported measles cases from about 500,000 cases and 500 deaths per year to a few dozen cases each year in the US.”


Parents must continue to vaccinate children to continue to see this success rate. Sadly, we have already seen the leaks in our immunity. Measles outbreaks are back! In early July, there was a measles outbreak in Brooklyn, NY In February 2008, San Diego was hit with an outbreak which lead to 11 children being infected with the disease and one baby being hospitalized.


So how did parents lose so much confidence in something that is proven to protect children from disease? In the July issue of the Journal of Specialists in Pediatric Nursing, Lisa Miller, MD, MSPH and CCIC Board Member Joni Reynolds, RN, MSN penned the article “Autism and Vaccinations – The Current Evidence” outlines the many concerns that parents have about the MMR vaccine and the evidence against a causal relationship between MMR and autism.


How did we get here?


We have been battling the false connection between MMR and Autism for over a decade.


It all started in 1998 with Dr. Andrew Wakefield and his survey of 12 children in which he concluded that 6 of the 9 children’s parent or physician linked the onset of developmental regression with the administration of the MMR shot. This study set off the fire storm around the MMR vaccine and this study has been closely scrutinized and questioned.


It is to be noted that by 2004 10 of 11 of Dr. Wakefield’s co-authors had retracted the interpretation and just this year, the Sunday Times reveled evidence that Wakefield fixed the data of his 1998 study.


As good stewards of science and holding public health as its number one priority, in fall 2000 the CDC and National Institutes of Health convened to examine the MMR vaccine. After examination of the science behind the issue,

“they rejected the causal relationship between the MMR vaccine and ASD based on the facts that there was a lack of epidermologicic evidence and lack of biologic models.”


Other countries also examined this issue, trying to recreate Dr. Wakefield’s results. The JSPN article outlines numerous studies which have examined this issue. Here are a few highlights:


In 2002, scientists in Denmark studies over one million children and found no difference in the risk of autism between MMR-vaccinated and unvaccinated children.


To pile on more evidence, even through Japan has withdrawn the MMR vaccine in 1993, autism rates continues to increase there.


In February of this year, The US Court of Federal Claims found that “after reviewing 5,000 pates of transcripts, 939 medical articles, 50 expert reports and hearing testimony from 28 experts” that MMR and thimerosal-containing vaccines do not cause autism.


Just recently on September 22, 2009, the National Health Service (NHS) Information Centre found that autism rates are consistent among adults is identical the rates of autism among children -at about 1%.


Autism is continuing to increase even though we’ve eliminated MMR as a cause. That’s one fear we can eliminate from our list.


The big bad Thimerosal


Scientists have also looked at the ingredients of the MMR vaccine for reasons why it could cause autism. One of its ingredients prior to 2001 was thimerosal.


Vaccine manufacturers widely used thimerosal as a preservative in vaccines. It is approximately 50% mercury by weight. Some say that mercury poisoning symptoms can look a lot like some of the symptoms of autism.


Thimerosal is an ethylmercury , which needs to be distinguished from methymercery.


Methylmercury is the dangerous mercury that accumulates in the brain and causes neurological damage. Methylmercury can be found in some forms of pollution and in some of our waterways.


Thimerosal has ethylmercury which does not accumulate in the body or the brain. It is metabolized and cleared from the body.


Regardless, the CDC has removed all thimerosal from most vaccines in an effort to boost public confidence. Since 2001, vaccines routinely administered to children under the age of 6 are produced without thimerosal except for some types influenza vaccines.


So since there is not thimerosal in MMR and thimerosal doesn’t cause neurological damage, we can eliminate it from our list of fears as well.


It’s time to protect our children again


We have exhausted all the possible connections to MMR and autism. It’s not the smoking gun some hoped it would be.

  1. Studies have found no difference in the risk of autism between MMR-vaccinated and unvaccinated children
  2. Thimerosal has been removed but autism rates continue to increase
  3. Thimerosal never was a cause of neurological damage
  4. Wakefield’s original study has been dismissed as falsified

I am empathic with concerned parents who want to find an answer to why the autism rate continues to climb. I am an advocate for finding research dollars to explore other avenues of causes for this devastating diagnosis.


I also want to protect children from disease. I want to save lives. I agree with the article when it states that “Vaccines are one of the greatest achievements of biomedical science and public health.”


Parents cannot continue to hold onto misplaced fear that by avoiding the MMR vaccine they can save their child from a diagnosis of autism. The MMR vaccine is protecting children. We have made great inroads over the years diminishing the necessity to fear disease because of the success of vaccination. Protect your children, immunize them.

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