Of course, I want to write about it. Wikipedia has a good background article on the Thimerosal controversy here, and thimerosal itself here. They also have articles on all the immunizations discussed here.
Certain subsets of people seem to think that there is nothing short of a global conspiracy to cover up the 'fact' that autism is caused by vaccines--probably the same people that shot JFK, tried to take over the US with black helicopters in the nineties, and are still witholding information about Area 51. Sorry, I had to poke a little fun.
As personal background: I believe in immunizations. Our children are immunized. With that said, we asked for thimerosal-free vaccinations, and we postponed certain vaccines. I see no reason, for example, that I, as a careful parent who attends pediatric visits, need to get my child vaccinated with Hepatitis B vaccine (a disease that is transmitted either by sexual contact or blood and body fluid exposure) on the day of birth. All our decisions to postpone and then complete vaccines were done with the assent of our pediatrician. I've never had an argument from them about postponing certain vaccines.
I recently received an e-mail about a website, Generation Rescue, that contends two main things: autism is reversible, and vaccines caused its rise. They have recently taken out ads in USA Today and the New York Times, among other outlets, contending that we are over-vaccinating our children, and this has led to autism increase, and it's being covered up. Both Don Imus and Robert F. Kennedy, Jr., have lined up along similar lines. They are mentioned on the above website.
I'm not on any sort of a smear campaign; I should say that it seems perfectly reasonable to remove thimerosal, a mercury-based preservative, from vaccines (which is why it's already been done for the most part). I also think that most of the therapies they list on their website for children likely do a lot of good--detoxification, correction of vitamin deficiencies, complementary medicine, and so on. They are also justified in sounding the alarm about the rise in autism, which is alarming. However. I do have a teeny-weeny bone to pick with them.
In part 1, I'll look at their specific ad, and say outright that it's misleading. They point to the increase in shots recommended by the CDC from 10 in 1983 to 36 in 2008. They then quote autism rates in 1983 as 1 in 10,000, rising to 1 in 150 in 2008. The ad is in PDF form here.
OK, let's be rational. First, are their incidence rates correct for autism or ASD (autistic spectrum disorders)? The 1 in 150 number looks accurate even according to the conspiratory and shady CDC (sarcasm intended, sorry, I'll try and keep it down) as seen here. However, they state that this incidence number has been relatively stable since 2000 or so, which will be important later on. What about the 1 in 10,000 number? A Google search reveals this article, which has an incidence of 5.5 per 100,000 in 1976, or 1 in 20,000 in Olmstead County, Minnesota. A couple other Google searches showed similar numbers; I don't see a footnote for the statistic, but it seems reasonable based on the above article. Overall, they have a point; there has been a rise in ASD prevelance (the total number of children affected by the disorder at any one time).
Now, how about the syringes portraying the number of vaccination recommendations and the 260% increase? Again, overall, they have a point that there are more shots recommended now as compared to 1983. However, there are some very important points to be made.
Point 1: MMR is present both in 1983 and 2008. It's not hard to do a web search and find supposed links between the MMR vaccine and autism. 60 minutes has done a piece on it. So, if the rate is rising, how could MMR be linked if it hasn't changed?
Point 2: along the same lines, rotavirus accounts for 3 of the 36 total 'shots', and varicella accounts for 2. Rotavirus was only just approved for use. Most importantly, though, rotavirus vaccine, a.k.a. Rotateq, is an oral vaccine, not a shot. The website makes the accurate point that injecting vaccines bypasses metabolism in the liver, but Rotateq does not and shouldn't therefore be in the list. 33. Varicella, or chicken pox, was only changed to be recommended in a two shot series in the last year or so, so recently that the CDC and state health departments aren't tracking adherence to the two shot regimen closely to monitor up-to-date rates. Both of these recommendations are so recent that there's no way they could contribute to the rise in autism, either. The same is possibly applicable to Hepatitis A, for which the recommendations are changing dramatically and often. It was only recently added to the general schedule.
Point 3: The 1983 schedule included the old version of pertussis (Whooping Cough). Interestingly enough, this vaccine was resisted because there were many reports of brain damage unproven by studies at the time, according to the Wikipedia article above, not dissimilar to the current controversy. That vaccine was replaced in 1992, meaning that the 2008 series is safer with regards to the new pertussis vaccine, which is not a live virus.
Point 4: The 1983 schedule contained the oral polio vaccine, which was likewise discontinued in the US and replaced in 1987 by a newer version of the inactivated polio vaccine. Why? It was thought to be contaminated by simian virus 40, linked to cancer but never proven. Again, the new schedule is safer.
Point 5: Seldom are children up to date on all of the vaccines listed. The CDC measures vaccine coverage with a so-called 4:3:1:3:3:1 count, for DTaP, Polio, MMR, Hib, HepB, and Varicella. As shown by this map, coverage is above 80% in only 12 of 50 states, and below 69% in 6. Vaccines such as Hepatitis A, the second Varicella booster, rotavirus, and Prevnar are not even counted because they were introduced or changed more recently, and it takes time for these changes to take effect.
Why do these matter? I'll discuss more in future installments on causation versus correlation and therapy. But these inconsitenciesand biases in the advertisement make me wonder about the conclusions. Does it seem reasonable to avoid mercury in vaccines? Yes (which is why the AAP advocated it years ago, discussed soon). Does it seem possibly reasonable to modify the vaccine schedule? Sure. Is it alarming that autism has risen? Yes (I'll talk more about that, too).
Is all this due to vaccines? Is it worth demonizing vaccines in a full-page advertisement? Is it worth returning to 'nature', so to speak, and letting Haemophilis Influenza, chicken pox, diptheria, tetanus, pertussis, influenza, streptococcus pneumoniae achieve whatever infection rates they would with no immunization?
It's easy to see that I think the answer to those last questions is an emphatic no.