More Evidence That Vaccines Don’t Cause Autism

Children exposed to high, low levels of thimerosal had similar odds for the disorder as children with no exposure to thimerosal, a new study has found. This should be absolutely no surprise for two reasons: (1) since thimerosal has been removed from virtually all vaccines, there has been an INCREASE (not a decrease) in autism, and (2) no study has found any evidence of an association between thimerosal and autism. Here are the details from this newest study from HealthDay News:

Infants exposed to the highest levels of thimerosal, a mercury-laden preservative that used to be found in many vaccines, were no more likely to develop autism than infants exposed to only a little thimerosal, new research finds.

The study offers more reassurance to parents who worry that vaccination raises their children’s risk for autism, the researchers said.

“Prenatal and early life exposure to ethylmercury from thimerosal in vaccines or immunoglobulin products does not increase a child’s risk of developing autism,” concluded senior study author Dr. Frank DeStefano, director of the immunization safety office at the U.S. Centers for Disease Control and Prevention.

The study was released in the journal Pediatrics.

Thimerosal has been used as a preservative in vaccines since the 1930s, according to background information in the article.

Concerns about the chemical began to crop up in 1999, when the U.S. Food and Drug Administration said that because of the increased number of thimerosal-containing vaccines added to the infant vaccination schedule, infants may be exposed to too much mercury. Thimerosal used to be found in hepatitis B, Hib (Haemophilus influenzae type B) and DTP (diphtheria, tetanus, pertussis) vaccines, among others.

During the ensuing years, the FDA worked with manufacturers to eliminate thimerosal from vaccines, according to the agency’s Web site. Today, thimerosal has been removed or reduced to trace amounts in all vaccines routinely recommended for children 6 years of age and younger, with the exception of inactivated seasonal flu vaccine, according to the FDA. Parents who are concerned about thimerosal can ask for a preservative-free version, DeStefano said.

And thimerosal wasn’t the only proposed autism-vaccine link. A 1998 paper in The Lancet suggested the MMR (measles-mumps-rubella) vaccine might trigger autism. The journal later retracted the paper, and numerous studies have refuted any link between the MMR vaccine and autism.

In February of 2009, a U.S. federal court ruled that there was no scientific evidence linking vaccines to autism.

In the new study, researchers examined medical records and conducted interviews with the mothers of 256 children with an autism spectrum disorder and 752 children matched by birth year who did not have autism. The children were all members of three health care management organizations in California and Massachusetts.

Researchers also gathered information about the manufacture and lot number of the vaccines that the children received, to determine how much thimerosal they were likely exposed to.

Children in the highest 10 percent of thimerosal exposure, either prenatally or between infancy and 20 months, were no more likely to have autism, an autism spectrum disorder or autism spectrum disorder with regression than children in the lowest 10 percent of exposure.

“This study adds to a large body of evidence indicating that early thimerosal exposure through vaccination does not cause autism,” said Geraldine Dawson, chief science officer for a leading advocacy group, Autism Speaks. Dawson was not involved with the research.

She urged parents to have their children vaccinated.

“We encourage parents to have their children vaccinated and to establish a trusting relationship with their child’s pediatrician so they can discuss any concerns they have,” Dawson said.

The U.S. Food and Drug Administration has more on thimerosal here.

3 thoughts on “More Evidence That Vaccines Don’t Cause Autism

  1. Wendy

    I still don’t want my child to have 35-40 vaccines by the time he’s in kindergarten. Maybe they don’t cause autism, but neuroscience studies have shown a link between vaccination and brain inflammation that can last for years and possibly decades. This assault to the child’s brain, from what I understand, triggers a process called immunoexcitotoxicity during the brain’s most critical period of growth and development. It can appear as learning difficulties, behavorial problems, language difficulties, or impulse-controlling difficulties. The elderly are at risk too because neurodegenerative diseases such as Alzheimers and Parkinsons are triggered and worsened by chronic brain inflammation (from Dr.Russell L. Blaylock, M.D. and neurosurgeon.) I don’t mind really important vaccines like polio, but I resent the pharmaceutical industry pushing vaccines like chicken pox and adding to the “required” list so that my child is supposed to have 35-40 vaccines by the time they are 5. No thanks.

  2. Reginald Finger

    Wendy has raised a list of issues that have been commonly expressed by a number of people both in professional circles and in the general public in the last several years.

    1) The concern about “35 or 40 vaccines by the time my child reaches kindergarten” is really threefold — a) cost, b) concern about number of times stuck with a needle, and c) possible concern over the number of antigens to which a child would be exposed over time. The third concern is really the easiest to deal with. The number of antigens (proteins that stimulate the immune system) are far more in the air, in our food, and all around us, than what would be seen in this number of vaccines. Actually, as the years have passed, the vaccine manufacturing process has improved and the “unnecessary stuff” that used to cause reactions has gotten less and less. The best example is the replacement of whole-cell DTP vaccine with DTaP (acellular pertussis) vaccine. Admittedly, cost and pain are real issues. It does cost a lot — sometimes a lot of it out of pocket — to immunize a child. And it is never very fun to be stuck with a needle. However when these are the focus, it is because we have forgotten the costs and pain that were endured when the diseases were common. Several times in the last few decades — the measles resurgence in the US in the late 1980s and the polio resurgence in Nigeria in the mid 2000s are two of the best examples — when vaccine coverage waned — the diseases came roaring back.

    There is always the concern that the pharmaceutical industry — with their profit motive — has too much influence over the CDC and others who make national policy. Part of is because it is hard to find experts who have not had some experience in industry — and part because former feds tend to drift into the industry because incomes are better there. However, I (whose involvement with the industry consisted of one $500 consulting assignment at a time when I did not sit on committee) served a 3-year term on the Advisory Committee for Immunization Practices and I can tell you that the amount of care taken to see that our deliberations and votes were independent of the industry, is impressive. We had to declare potential conflicts at the table, in front of media microphones, at each and every meeting.

    With regard to the “immunoexcitotoxicity” issue, I do not find reference to it in the medical literature except by Dr. Blaylock. While admittedly his expertise in neurosurgery is considerable, his publications outside neurosurgery are review articles — not original research. What this says is that before one buys into the theory, one ought to look for considerable corroborating published evidence from some other sources. Meanwhile, I do have some experience with the vaccine safety research and regulation system at CDC and find it to be very thorough. The speed at which the first rotavirus vaccine got pulled off the market in 1999 is one of the best examples. I do not believe that CDC scientists have been involved in a cover-up as Dr. Blaylock suggests. The tendency — and I have been to a lot of meetings at CDC, immunizations and otherwise — is to be totally focused on data and scientific process wherever it may lead. Ideological agendas are not well received there.

    All in all, I believe that each concern needs to be taken seriously on its merits, and I also believe that up to this point, when this has been done, that the vaccines on the recommended schedule have passed the test both in terms of the well-being of the individual patient and the well-being of the whole community. These issues will continue to be researched and debated for years to come.

    Reginald Finger, MD, MPH
    Colorado Springs, CO

  3. Dr. Walt

    Many thanks to Dr. Finger, who I consider an objective expert in the area of vaccinations, for his response and comments.

    BTW, Wendy, I looked up Dr. Blaylock, and, unfortunately, both he and his publication are listed on QuackWatch.com. That’s NOT a good thing and I’d never recommend anyone take any advice from someone who is suspected to be involved in quackery or fraud (and, I’m NOT saying Dr. Blaylock is, as I don’t know — but, just to say that he’s listed on this site).

    First of all, he’s listed among the “Promoters of Questionable Methods.” The site says, “Each of the following has been involved in some way with the promotion or administration of questionable health products and/or services or with opposition to beneficial methods. Many of them have written at least one book that I believe contains invalid information. Most appear to hold sincere beliefs.” (http://www.quackwatch.org/11Ind/index.html)

    Also, the “Blaylock Wellness Report” is on the QuackWatch list of “Nonrecommended Periodicals,” about which they say, “I consider these publications untrustworthy because they promote misinformation, espouse unscientific theories, contain unsubstantiated advice, are insufficiently skeptical, and/or fail to distinguish between reliable and unreliable sources of advice.”

    I hope these comments help you in your search for advice and information that is trustworthy, evidence-based, and medically reliable.

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