In 1998, there was a groundbreaking study telling parents that their children were at risk of getting autism from vaccines. Parents everywhere collectively gasped. After all, they had been told for years vaccines were the best way to prevent any number of unwanted diseases. Now they find out the very treatment they thought was making their children better could potentially result in devastating consequences, at least in the case of low-functioning Autism.
The only problem was that same study published in the Lancet was later retracted. Its author, Andrew Wakefield, was shown to have falsified data. His "science" proved to be fraudulent, and riddled with conflicts of interest. His research was so void of ethics that the British General Medical Council removed him from the medical registry and he's no longer allowed to practice medicine in the United Kingdom.
The damage, however, was done. As with so many other societal perceptions based on debunked science, vaccines causing autism is still a very real concern for many parents. In a survey published in Health Affairs in 2011, 30%-36% of parents were concerned that their children were given too many vaccines in the first 2 years of life, and that those vaccines might cause learning disabilities (like autism). 10% say they will delay, or refuse vaccinations believing it's safer than following the recommended CDC schedule.
To put this issue to bed, let me say, as a medical professional who has researched this extensively (and someone who has two members of my family who are on the autistic spectrum; so this is a subject I was already quite familiar with even before doing the necessary research to answer this question)- there has never been a single reputable study ever performed that demonstrates any link between vaccines and autism. In fact, countless studies have shown there is absolutely no link between the two.
No, vaccines do not cause autism. To understand why I'm so confident in saying that, let's throw some good science at this myth, learn a little about Autism and vaccines, and see if we can't quiet down the naysayers.
Autism, in general, is a broadly defined developmental "disorder". Those diagnosed can have a wide range of cognition issues and abnormal behaviours. They can have significantly different social, behavioural, and intellectual abilities. Due to this, the term Autism Spectrum Disorder (ASD) is now used to describe the many differing presentations.
Because there are so many misconceptions about these presentations, even among psychiatrists and doctors (and I think in many instances the prevailing views are just flat wrong from my experience), I'll just refer you to an absolutely phenomenal article by Maia Szalavitz about the work of famed neuroscientist Dr. Henry Markram (director of the Blue Brain Project, an attempt to create a synthetic mammalian brain, and director of the Human Brain Project, an attempt to simulate the human brain using supercomputers).
Dr. Markram also found that the prevailing views among scientists and psychologists about autism simply didn't line up with what he was seeing with his own son's autism and other cases he studied. Being one of the world's leading neuroscientists, he has since leveled his amazing brain at the problem. Joining him in this endeavour is the equally impressive brain of his wife, Dr. Kamila Markram.
After a breakthrough involving observing hyper-connected cells in the subjects they were studying, the two came up with a theory which, in my experience (and, of course, theirs as you'll see), seems much closer to the mark when you actually live with people on the spectrum and get to be around them all the time. For instance, among other things, you'll see he debunks the whole "lack of empathy" thing. Here's the article:The Boy Whose Brain Could Unlock Autism
They also note in their research that the cells in question aren't defective nor under-responsive, but in fact have many more connections than normal, making the network able to learn significantly quicker, which if not controlled correctly in the learning, particularly in the early stages, can have amazingly negative results. For instance, in testing, rats with this abnormality not only learned much more quickly to get scared of something that would shock them, but they also quickly became terrified of not just the electrified object, but everything they associate with the shocking, such as colours and smells, and the like. The rats also had a significantly more difficult time unlearning all these very strong associations.
Imagining an entire world where experiences are bombarding the autistic brain in this way led to the Markram's "Intense World" theory of autism, which also perhaps explains why it takes so long for babies to manifest strong symptoms of autism in many cases. They start out more or less with a blank (apparently hyperconnected) slate, after all.
In any event, whether Dr. Markram turns out to be correct or the more widely touted classical views, the exact mechanism within the brain that causes these wide ranging neurodevelopmental problems is still up for debate, though the Markram's research is very promising.
But back to vaccines, if the Markram's are correct, vaccines wouldn't have any affect on the situation. This hyperconnectivity is a prenatal development.
But what about the more commonly accepted theories? After all, the Markram's work needs thoroughly vetted before we should accept it, no matter how promising it looks.
For the more commonly accepted theories, it's thought likely that not any one disease process, but a group of conditions with related symptoms, is occurring. Genetics and environmental conditions both playing a role in those affected. (Which still *sort of* is in-line with the Markram's theory, which is why they recommend "toning down" the autistic baby's environment in early development, but I'll stop harping about it. Go read Maia Szalavitz' article on the Markram's work right now! I'll wait…)
Again, going back to the commonly touted line of thinking, we know that those diagnosed have atypical neural connectivity within their brains, such as different neural processing of eye gaze direction using EEG (Electroencephalography). We know genetics plays a role, as studies have shown siblings of children diagnosed with ASD have a 15%-20% chance of showing symptoms compared to just 1% for those at low risk. Several known chromosomal deformities, such as Fragile X syndrome, tuberous sclerosis, Joubert's syndrome, and duplications of the chromosomes 15q11-13, can result in a diagnosis of autism.
As to vaccines, there are many types. Some have live microbes that cause an immune response, some have inactivated microbes that also cause an immune reaction. Others have just the antigens that cause an immune response and not the entire microbe itself. The one that gained such popularity as the potential cause of autism was the MMR (measles, mumps, rubella).
In his study published in the February 1998 issue of Lancet, Dr. Wakefield stated
Onset of behavioural symptoms was associated by the parents with measles, mumps, rubella, vaccination in eight of the 12 children…. All 12 children had intestinal abnormalities…..behavioural disorders included, autism (9), disintegrated psychosis (1), and possible postviral or vaccinal encephalitis (2).
His interpretation was that the gastrointestinal problems and the developmental regression (associated with autism) were associated with environmental triggers. Basically saying the trigger was the MMR vaccine.
Immune system responses have long been shown to come with some gastrointestinal symptoms. It's not too far fetched then, to try and show a link between those symptoms and vaccines. A person might also try and postulate a theory to show how those symptoms that are associated with certain disorders (like the often proposed gastrointestinal problems with autistic children) might be caused by those vaccines.
The fraudulent disconnect with this myth is trying to say the cause of the symptoms is also the cause of disease processes that results in those same symptoms, even though it has never been shown that ASD sufferers are actually more prone to GI problems than the general population.
It probably didn't hurt that Mr. Wakefield, who used the GI problems as a link in his now defunct study,was a paid consultant to attorneys who represented parents that thought their kids had been harmed by vaccines.
The question Mr. Wakefield presented isn't inappropriate to ask. The problem came when others looked at his falsified methods, and attempted to replicate his results. Falsified data aside, numerous studies performed between 2002-2005 showed no link between autism and the MMR vaccine.
In April of 2013, another study published in The Journal of Pediatrics once again showed no link between exposure to vaccines and autism. As others before, this study showed that it didn't matter how many vaccines the children received, whether all at once or given over time- there was no increased risk of developmental problems.
Due to so many conditions potentially affecting symptoms of ASD, this study, like so many others, points out that possible effects of immunological exposure in early infancy can't be ruled out altogether. However, as noted, our lack of understanding of exactly what is going on with autism is the primary driver of that small shred of doubt, not any indicator.
However, they also stated, "We found no association between exposure to antigens from vaccines during infancy and the development of ASD with regression". Further, "The possibility that immunologic stimulation from vaccines during the first 1-2 years of life could be related to the development of ASD is not well supported by the known neurobiology of ASD, which tends to be genetically determined with origins in prenatal development."
Based on the study published by Mr. Wakefield in 1998, parents were right to be concerned about vaccines causing autism. In the end, though, good science prevailed and has since shown us that there is absolutely no observable link between vaccines and autism. Babies that are vaccinated and those who aren't have the same rates of autism.
So while the choice is yours on whether to have your baby vaccinated, at least you now know autism isn't something you should consider when making this decision.
Picture: Shutterstock/Khamidulin Sergey
Scott writes for the wildly popular interesting fact website TodayIFoundOut.com. To subscribe to Today I Found Out's "Daily Knowledge" newsletter, click here or like them on Facebook here. You can also check 'em out on YouTube here.