Recently a new study came out which suggested that changes to the brains of autistic children might be detectable as early as 6 months of age. Steve Novella has covered this particular study at his Neurologica blog so there is no need to repeat what he said there. Predictably, the anti-vaccination crowd has come out restating their belief that vaccinations are still to blame. Now, to be fair nothing in this study proves that vaccines cannot cause, or have any effect on, autism. All it says is that it may be possible to notice differences in the brain as early as 6 months of age, and even at that it does not provide a diagnostic tool, due to its size (92 infants) and limitations. It certainly points to an interesting direction, but I do not believe any strong conclusions can be drawn from it.
If the results can be replicated in larger studies though, it would certainly lay to rest one of the myths about vaccines and autism, namely the one that maintains that vaccines given at or around the age of 2 cause autism, i.e. it would exonerate the MMR vaccine for example. But that is not what I wish to deal with today. What I do wish to deal with today is the common anti-vaccine conundrum that “there isn’t a single study on the cumulative effects of vaccines on (fill in the blank)“. You will always hear this from the anti-vaccine crowd, especially when the topic of autism is being discussed. Superficially it seems to make sense, after all if we’re giving vaccines to children why shouldn’t we test if in the cumulative they cause autism?
The problem is, of course, that there are thousands of afflictions that one could choose to blame vaccines for, and then turn around and ask why a cumulative study of the effects of the vaccination schedule on that particular affliction has not been done. The list could include, but not be limited to:
- Cancer (all types)
- Bone breakage
- Heart problems
- Lung problems
- Kidney failure
- and on, and on, and on
I wish to be clear that I do not mean to make light of the seriousness of autism as a disorder. The point is that we could pick literally hundreds of things to blame on vaccines and demand cumulative studies to be done, and maintain the vaccines are to blame until said studies are done, effectively perpetually moving the goal post so that vaccines are never considered “good enough”. Even the most strident anti-vaccine activist has to concede that research money is limited and we cannot possibly run studies about everything, so a certain level of plausibility must be established before studies of this magnitude are to be undertaken.
Also, that is why when a new vaccine is introduced to the schedule, studies comparing children that received that vaccine, and children that did not are done, and analyses are performed to see if anything out of the ordinary develops in the vaccinated group. Instead of testing for every possible affliction one at a time, we compare the two groups to see if anything at all presents at statistically significant levels in the group receiving the vaccine. If a signal comes through, then it is warranted and justified to do studies specifically on that.
Yet the vaccine schedule is not the only thing that has changed since the 80s. It is not true that besides the number of vaccines, everything else has remained constant between then and now. If that were the case, at least I would say the anti-vaxers hypothesis is plausible. How many things have changed dramatically between then and today? And a follow up question then becomes: how many of those have been tested for their cumulative effect on autism rates?
Here I wish to start a list of the major differences between the life a child born in the 80s and now in the developed world, because any one of those, or any combination thereof, could in theory have affected autism rates and be responsible for the increased autism diagnoses.
Please feel free to add to the list in the comments section and I will keep updating the entry with your suggestions.
List of things that have changed since the 80s that could affect autism rates but most likely have not have been studied for their effects on autism (either on their own or in any combination)
- High Speed Internet
- MP3 players
- Flat Screen TVs
- Average # of toys children own
- Car Ownership
- Hybrid Cars
- Reality TV
- Game Consoles (Wii, SPS etc.)
- Bike helmet use
- Time spent outdoors
So if many things have changed between the 80s and now, along with the vaccination schedule, if we have studies suggestive that signs of autism are detectable as early as 6 months of age, thus implying they have been there earlier than that, then why do we single out vaccines as the culprit? How can one possibly, reasonably maintain that vaccines cause autism?