It turns out, the new H1N1 vaccine (the one that the Centers for Disease Control and Prevention and even President Obama have been pushing so strongly) contains an ingredient that may have some parents worrying. Thimerosal is a mercury-based preservative that has been phased out of childhood immunizations since 2001 due to concerns that the preservative MAY be linked to autism. But thimerosal (which is about half-mercury) will be found in most vials of the H1N1 vaccine. However, it may be possible to find doses that are thimerosal-free if you ask for single-dose shots. According to the CDC, "Single-dose syringes will be thimerosal-free, which will address concerns about this additive, especially regarding pediatric and pregnant vaccine recipients (inhaler sprayer vaccine products also will be thimerosal-free)."

The sheer amount of news stories, studies, interviews and papers released on the potential link between childhood vaccines and autism is nothing short of mind-numbing -- as is the amount of finger-pointing, contradictions and paranoia that exists on both sides of the debate. For every study that you find that either proves or disproves the connection between vaccines and autism, you will find a laundry list of concerns regarding the way the studies were set up and who funded them.

Complicating the issue further is the possibility that the link between autism and vaccines (if there is one) may not be clear cut. It's entirely possible that vaccines may trigger autism in children who are "genetically susceptible" to the disease. It's also possible that it is not any one vaccine (or vaccine component) that can be linked to autism -- but rather the fact that so many vaccines are given in so short a time -- that may cause trigger the onset of autism.

In other words, regardless of your stance on the vaccine/autism issue, there is no shortage of information to support and/or refute your claim. I'm not a doctor, nor do I pretend to be one online. But I do think that parents need to learn as much as they can about these issues in order to make the best decisions for their kids. With that said, here are some links that offer more details about vaccines and autism.

PRO-VACCINE

There is no link between vaccines and autism.

• CDC (www.cdc.gov/ncbddd/autism/vaccines.htm): "The weight of the evidence indicates that vaccines are not associated with autism."

• American Academy of Pediatrics (www.cispimmunize.org/fam/safety_parent.html): "There is no scientifically proven link between measles vaccination and autism."

• Dr. Paul Ofitt, director, Vaccine Education Center, Children's Hospital of Philadelphia: "Studies of 1) the genetics of autism, 2) the timing of the first symptoms of autism (home-movie studies), 3) the relationship between autism and the receipt of the MMR vaccine, 4) the histopathology of the central nervous system of children with autism, and 5) thalidomide, natural rubella infection, fragile X syndrome, and tuberous sclerosis all support the fact that autism occurs during development of the central nervous system early in utero." (From "Vaccines and Autism": http://www.immunize.org/catg.d/p2065.htm)

• FDA (www.fda.gov/fdac/features/2004/504_iom.html): "There is no link between autism and the measles-mumps-rubella (MMR) vaccine or the vaccine preservative thimerosal, according to a report released by the Institute of Medicine's (IOM) Immunization Safety Review Committee" (www.nap.edu/catalog.php?record_id=10997).

• National Institutes of Health (www.nichd.nih.gov/publications/pubs/autism/mmr/sub2.cfm): "To date there is no definite, scientific proof that any vaccine or combination of vaccines can cause autism."

ANTI-VACCINE

There is a strong link between vaccines and autism.

• K.N.O.W. Vaccines (Kids Need Options With Vaccines) (www.know-vaccines.org/autism.html): "The strong correlation between autism and vaccine history becomes even more credible when the disease characteristics for both autism and mercury poisoning are compared."

• Autism Research Institute: List of studies linking thimerosal and/or the MMR vaccine to autism: Part I (www.autism.com/triggers/vaccine/thimerosalreferences.htm) and Part II (www.autism.com/triggers/vaccine/mmrreferences.htm).

• "Evidence of Harm" (www.evidenceofharm.com): 2005 book identifies a possible link between thimerosal and rising rates of autism.

• Generation Rescue (www.generationrescue.org): Jenny McCarthy's organization that researches the causes and treatments for autism.

• Adventures in Autism (adventuresinautism.blogspot.com): The blog of Ginger Taylor, and "autism mom" who writes about "news and commentary on the autism epidemic and my beautiful boy who is living with autism."
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