However, there is no evidence of a link between vaccines and autism, and no matter how much parents want to believe that they have found the cause of their child's autism, they simply haven't.

The only study linking vaccines to autism (Wakefield, the Lancet, 1998) was conducted on a mere 12 children. The theory posited by the study, that poor absorption of nutrients caused by inflammatory bowel disease leads to developmental disorders, isn't supported by the clinical data. In at least four of the 12 cases the behavioral problems began before the onset of the inflammatory bowel disease (the purported mechanism for autism development).

In a later study conducted by the same researchers (Wakefield, et. al.), specific laboratory examinations of intestinal tissue in patient with inflammatory bowel disease turned out negative for the measles virus.

Moreover, the effectiveness of the MMR vaccine is well-documented and thoroughly researched. The life-threatening illnesses children face from getting measles, mumps or rubella far outweigh the risks associated with the vaccine. These risks, which are nonfatal and affect a few children per million, are identified and reported every year to the VAERS (Vaccine Adverse Event Reporting System), so doctors can ensure vaccine safety.

Unfortunately, vaccines are not 100 percent effective. Some children are simply resistant to developing immunity to diseases. So when children who could develop immunity to measles, mumps or rubella avoid getting vaccinated, they increase the chances they will infect someone who has no or less protection from those diseases.

By promoting a mother's impassioned plea and conspiracy-theory support group sessions as equal to the mountains of scientific evidence supporting vaccination, you are encouraging parents to believe that their own intuition is the best judge of scientific facts. This leads to unscientific fear-mongering, which endangers the lives of not only their own children, but other children around then. (For reference information about vaccines and autism, read here -- specifically, section 9.)

Fighting against vaccination will not decrease the incidence of autism. It will only lead to an increase in deaths that could be easily prevented.

-- Joshua Burgin .

Unfortunately, the fact that a disease only appears after the first year of life doesn't rule out a genetic explanation, as Lesli Mitchell asserts. Many other genetic problems only surface much later than that. Huntington's chorea and ALS are two adult-onset examples: Woody Guthrie and Lou Gehrig appeared perfectly healthy, too.

Regarding the ethics of biomedical research, as someone who does it for a living, I can cite many, many examples of medications that fail in safety trials despite huge financial incentives for them to succeed. While there have been botched studies and faked data (the business is conducted by humans), I have to resist the implication that it's the norm.

-- Derek Lowe

The author's self-described "Pitocin-and-epidural labor," and the formula-ear infection-antibiotic cycle might also be involved in the increase in allergies, asthma, ADHD, learning disabilities and seizure disorders, as well as autism. These drugs are thrown at infants as commonly as vaccines are.

-- Donna Maindrault

I am a mother of an autistic child and I am sick and tired of hearing about how this or that "causes" autism, when the truth is that a) there are several indicators pointing to a genetic factor, and b) many parents who claimed their child developed normally the first year are usually only looking at motor skills (which are mainly listed in most childhood publications) and do not seek out charts listing specific social/emotional skills and language development.

The connection to ear infections is also laughable. My daughter is 6 and has had two ear infections in her entire life, both after the age of 4. My daughter's developmental pediatrician and I discussed her first year and found that she was displaying autistic symptoms within 24 hours after birth, and only got worse (which was missed because everyone focuses on motor skills during the first year and communication/socialization isn't looked at very hard until the second year).

Why don't you do a story about the real face of autism -- a child whose parents dare to admit that symptoms were present at birth -- instead of trying to blame coincidences?

-- Christine Moore

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