On Jenny McCarthy, Autism, and Dogma in Science

It is unfortunate that so many caring people with good intentions are terribly misinformed, and as a result are making bad decisions about their children's health. I'm speaking of course about the popular misconception that vaccines cause autism or other diseases.

While it is possible that research has overlooked something, there is currently no evidence for a vaccine-autism link. Nonetheless, Jenny McCarthy continues to argue against the United States' vaccination program, in her article, "In the Vaccine-Autism Debate, What Can Parents Believe?" for the Huffington Post.

For some reason, parents aren't being told that this "new" information about Dr. Wakefield isn't a medical report, but merely the allegations of a single British journalist named Brian Deer. Why does one journalist's accusations against Dr. Wakefield now mean the vaccine-autism debate is over?

Ms. McCarthy would have us believe Brian Deer's accusations came out of the blue, tarnishing a respected scientist's research. However, co-authors were pulling out on the infamous paper as early as 2004, and almost a year ago, The Lancet retracted the paper altogether. It isn't only a single journalist is accusing Dr. Wakefield either: last year a panel found him guilty of 'acting unethically' and he has been removed from the medical register (in the UK,  this is tantamount to losing his license to practice medicine).

The 'debate' is over because no reliable evidence has ever been put forward for that side. The debate has been over since study after study* showed no autism-MMR link, autism rates continued going up despite the removal of Thermisol.

I know children regress after vaccination because it happened to my own son. Why aren't there any tests out there on the safety of how vaccines are administered in the real world, six at a time? Why have only 2 of the 36 shots our kids receive been looked at for their relationship to autism? Why hasn't anyone ever studied completely non-vaccinated children to understand their autism rate?

Sympathy for the plight of Ms. McCarthy's child notwithstanding, this anecdote is not evidence--regression could have many causes. Just because the shot preceded the regression doesn't mean it caused the regression--that would be the Post Hoc fallacy.

I admit, that last question was a bit trickier for me to answer, until I stumbled upon the answer in a meta-study:

No studies have compared the incidence of autism in vaccinated, unvaccinated, or alternatively vaccinated children (i.e., schedules that spread out vaccines, avoid combination vaccines, or include only select vaccines). These studies would be difficult to perform because of the likely differences among these 3 groups in health care seeking behavior and the ethics of experimentally studying children who have not received vaccines.

This comes from "Vaccines and Autism: A Tale of Shifting Hypotheses" in the peer-reviewed Clinical Infectious Diseases.** If you're interested in this debate, I highly recommend it, as it is understandable after a little background reading. It lays out a pretty thorough case against anti-vaccination claims. Anyway, back to Ms. McCarthy's article:

These missing safety studies are causing many parents to approach vaccines with moderation. Why do other first world countries give children so many fewer vaccines than we do? What if a parent used the vaccine schedule of Denmark, Norway, Japan or Finland -- countries that give one-third the shots we do (12 shots vs. 36 in the U.S.)? Vaccines save lives, but might be harming some children -- is moderation such a terrible idea?

The CDC has an excellent answer to this, in their list of misconceptions about vaccinations:

These studies have shown that the recommended vaccines are as effective in combination as they are individually, and that such combinations carry no greater risk for adverse side effects. Consequently, both the ACIP and AAP recommend simultaneous administration of all routine childhood vaccines when appropriate.

(Emphasis mine) Also note their "risk from disease vs. risk from vaccines." The larger number of vaccinations in America's schedule seems to be because other countries aren't vaccinating against as many illnesses as the United States is. Recent research indicates that autism is probably tied to factors that vary from region to region. In other words, not the vaccine schedule uniform across the country.

With regards to autism, there's no room for dogma: research is ongoing on the causes and risk factors. So while we must not cave in to unsupported assertions, we do have to realize, given our current state of knowledge, ideas about the condition are subject to change as science marches on.

* Here are the links to the studies themselves:
Lack of Association Between Measles-Mumps-Rubella Vaccination and Autism in Children: A Case-Control Study (Polish study cited by Reuters) 
Lack of Association between Measles Virus Vaccine and Autism with Enteropathy: A Case-Control Study (Study covered by MSNBC)

**Stanley Plotkin, Jeffrey S. Gerber, and Paul A. Offit Vaccines and Autism: A Tale of Shifting Hypotheses Clinical Infectious Diseases 2009 48: 456-461.
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