I hadn't planned on blogging about vaccines again for a while. Really, I hadn't. Even I realize the risk of beating the proverbial dead horse just one time too often. Also, It seems that I've been writing about antivaccination loons a lot lately, even more than usual. However, aside from a prime time spot for antivaccinationist propganda, the news has been mostly good, with study after study poking holes below the waterline in the hull of the rickety rustbucket of a boat that is the whole antivaccinationist belief that vaccines cause autism.
This time, in yet another in a series of slaps in the face to Andrew Wakefield, the antivaccinationist paid by trial lawyers to find evidence linking the MMR vaccine to autism, the better to allow lawsuits to proceed. Of course, his "evidence" for a link between MMR and "autistic enterocolitis," published in 1998, was so incompetently obtained and written up that most of his coauthors ultimately disowned the study. Sadly, it was too late to prevent a wave of antivaccination hysteria to sweep the U.K., leading to a rapid drop in MMR vaccination rates and a massive increase in new measles cases, including at least one death.
In the nearly ten years since Wakefield almost single-handedly trashed the vaccination system in the U.K., no one has been able to replicate his findings. Now, hot on the heels of a study showing that thimerosal in vaccines is not associated with autism, making the rounds in the media is a study that examined the question of whether the MMR vaccine (which does not contain thimerosal) is associated with autism. Coming from Professor Gillian Baird at the Newcomen Centre for Child Development at Guy's Hospital in London, it's entitled Measles vaccination and antibody response in autism spectrum disorders.
Basically, the investigators tested the hypothesis that measles vaccination is involved in the pathogenesis of autism spectrum disorders (ASD. One prediction of such a hypothesis is that signs of a persistent measles infection or abnormally persistent immune response shown by circulating measles virus or raised antibody titers would be found in children with ASD who had been vaccinated against measles, mumps and rubella (MMR) as compared with controls. The methodology of the study was a community-based case control studying a cohort of 56,946 children born between July 1, 1990 and December 31, 1991 in 12 districts in the South Thames district of the U.K. At age 9-10 years, children with a diagnosis of ASD or a statement of special needs and the results used to identify a subset of 255 of the 1,770 children so screened who received an in-depth diagnostic assessment to identify characteristics of their autism or other learning disabilities. These were the subjects selected for the study. From these, blood was obtained from 101 with a diagnosis of autism or ASD and 55 special needs children with other diagnoses for comparison. The children with ASD were further examined for gastrointestinal symptoms or a history of regression. In addition, 98 children without a diagnosis of ASD or other learning disability were also recruited as controls. Although all of these children had been vaccinated, but some had not received both doses of the MMR. Ultimately adequate samples were obtained from 98 with ASD, 52 with a special needs diagnosis but no ASD, and a normal typically developing group (n=90).
So what did Baird and her colleagues find?
No correlations, nada, zip. There was no correlation between ASD cases and controls for measles antibody response and no dose-response correlation between autistic symptoms and concentrations of anti-measles antibody. There was no evidence of a differential response to measles virus in children with ASD, regardless of whether there was a history of regression, and controls. There was no difference between levels of measles virus detected and the presence of an ASD diagnosis. Of all the children, only one of the children from the control group had symptoms of enterocolitis, and there was no evidence of increased incidence of enterocolitis in autistic children with regression. This study was about as negative a study as you can get, and it's consistent with two earlier studies. It was also the largest reported and characterized by well-defined criteria for regression. Moreover, a highly sensitive assay was used to assay measles antibody. One aspect of the study that may have had an impact on how the results turned out is that this was not blinded. Parents knew that the study was about MMR, which may have led to a bias in who agreed to enroll their children. Of course, if anything, such a bias, if it existed, would have made it more, not less, likely that this study would have found a difference between children with ASD and neurotypical controls, making the negative result of this study even more resounding. It was also noted that children with ASD or special needs were more likely not to have had both MMR doses.
Professor David Salisbury, director of immunisation at the Department of Health, said: "It's natural for parents to worry about the health and wellbeing of their children and I hope this study will reassure them that there is no evidence linking the MMR vaccine to autism."
Public health experts will be hoping this study can lay to rest the controversy.
The Department of Health stressed the quality of the study and in a statement said it had "linked very careful assessment and diagnosis of a child's condition, with expert analysis of blood samples".
Sadly, I doubt that even this study will lay to rest the "controversy." It probably would if the debate were about science, but it's not, and no amount of evidence seems adequate to persuade antivaccinationists. Nevertheless, this has been yet another in a long line of studies that have failed to support the claims of antivaccinationists that either thimerosal in vaccines or vaccines themselves cause or contribute to autism. Indeed, it's becoming clear that they're feeling the heat from all this negative data, to the point that their justifications and rationalizations are becoming increasingly divorced from anything resembling reality. Indeed, recently Mark Blaxill whined in a most hilariously self-righteous manner that the bloggers criticizing antivaccinationists are a bunch of meanies. Clearly, Blaxill must have limited or no experience with Usenet or other discussion forums if he thinks I'm mean--or that any other of the bloggers on "our" side are particularly mean--particularly in comparison to bloggers on "his side." If anyone deserves the name "whackosphere," it's mercury militia bloggers. (John Best, anyone?) Meanwhile, Dan Olmsted is even more hilariously whining about being called out by Autism News Beat for his sloppy reporting and unsupported claims that autism is rare among the Amish and his implication that it must be because the Amish don't vaccinate. (Never mind that the Amish are inbred, don't use modern technology, live a rural, agrarian lifestyle, and have any number of differences when compared to the vast majority of Americans who do are not Amish--it's so obvious that if a difference in autism prevalence between the Amish and the rest of us exists it must be those evil vaccines!)
The belief that either thimerosal in vaccines or vaccines themselves causes autism is a discredited idea. Contrary to the claims of antivaccinationists, it is a hypothesis that has been investigated extensively, the results of these studies being published in the peer-reviewed biomedical research literature. No reputable researcher publishing in a good peer-reviewed journal has presented convincing evidence (or, in most cases, even any evidence at all) of a link. It's time to move on to other more promising areas of inquiry with regards to the causes of autism, because science has made it pretty much as clear as it is able to do that vaccines are not one of the causes.
To point this simple observation out strongly (and, yes, even sarcastically when certain members of the Ferrous Cranus sect continue to cling irrationally to mercury in vaccines or vaccines themselves as a cause of autism, no matter how much evidence is thrown at them that fails to support a link) does not, as one person has claimed, imply a "convenient rejection of our children's health problems." Far from it! It is because we are tired of seeing so much fruitless effort and expense wasted chasing after discredited hypotheses rather than more promising avenues of investigation. Moreover, as much as we can sympathize with the difficulties that many parents of autistic children have in raising their children and trying to find help for them, contrary to what some of them seem to think, their challenges and heartbreaks do not and should not immunize them from criticism when they promote antivaccinationist claims that are not supported by science. Criticism of the support of some of these parents for antivaccine pseudoscience is not a rejection of their children's health problems, but rather a means of pointing out that they have gone down a blind alley in looking for reasons for their children's condition and that they need change course. The contempt that I sometimes heap upon antivaccinationists comes from the knowledge that it is they who are clearly oblivious to the harm to all our children's health that their views can engender.
Baird, G., Pickles, A., Simonoff, E., Charman, T., Sullivan, P., Chandler, S., Loucas, T., Meldrum, D., Afzal, M., et al, . (2008). Measles vaccination and antibody response in autism spectrum disorders. Archives of Diseases of Childhood DOI: 10.1136/adc.2007.122937
Does anyone have a link to a simple citation listing (bibliography) of published studies which do show no link between vaccination and autism? Is there such a simple list in existance? It would make my life easier whenever I have to deal with some hysterical person who says, "There's not enough evidence to be sure it's safe for my children" to be able to point them towards a single, regularly updated list of study after study which shows just exactly that.
The antivaccinationists will never learn, will they?
Here is a (decidedly unscientific) study establishing the genetic basis of ASD:
I am high-functioning autistic. In the 13 people related by blood to me within five degrees (2 parents, 2 siblings, 2 aunts, 1 uncle, 2 first cousins and 4 grandparents) 4 have or had while living an autism-spectrum disorder. That works out to about 30%, which, incidentally, is the same number that share another trait with me (blue eyes) - not the same 4 people, of course.
All 14 of us have been vaccinated. I know the sample size is absurdly small, but really. If family records going back to the 1800's (before widespread immunization programs!) indicate a prevalence of what is now believed to be ASD, that seems genetic, yes?
I know that my family is not the only one with this type of prevalence.
I, too, am incredibly sympathetic to the parents of severely autistic children. I can't imagine how hard that would be (I know my high-functioning autism was hell on my parents when I was growing up). But the vaccines did not cause this! These parents, desperate for an explanation (any explanation) have settled on vaccines. I pity them, and, on a certain level, admire their dedication to the cause of helping their children. Yet I refuse to coddle them. They are wrong. I hope that one day they will all see the light.
The only "link" harder to find than the link between vaccination and autism, is the link between intelligence and the anti-vaccinationists.
And in other news, there are three kids who attend a charter school in San Diego who actually have measles. None of them were given the MMR:
Liesele, you can do a search for papers noted in this blog, or search PubMed, or you can check this:
Luckily I had an argument about MMR linked to autism some time ago, so here is a list of scientific references that support the "no-link" argument. By the way, this list is not complete! There are others as well.
- - Peltola H & Patja A, Leinikki P, Valle M, Davidkin I and Paunio M (1998) No evidence for measles, mumps and rubella vaccine associated inflammatory bowel disease or autism in a 14 year prospective study (Research letters) Lancet 351:1327-8
- - Gillberg C & Heijbel H, (1998). MMR and autism [commentary]. Autism, The International Journal of Research and Practice; 2:423-424.
- - Taylor B et al (1999) Autism and measles, mumps and rubella vaccine: no epidemiological evidence for a causal association. The Lancet; 353: 2026-29.
- - Kaye J et al (2001). Mumps, measles and rubella vaccine and the incidence of autism recorded by general practitioners: A time trend analysis. British Medical Journal 322 :460-3.
- - Farrington P et al (2001). MMR and autism: Further evidence against a causal association Vaccine 19:3632-5 Volume 19, Issue 27, 14 June 2001, Pages 3632-3635
- - Black C (2002) Relation of childhood gastrointestinal disorders to autism: nested case-control study using data from the UK General Practice Research Database. British Medical Journal 325 :419-21.
- - Taylor B et al (2002) Measles, mumps and rubella vaccination and bowel problems or development regression in children with autism: population study. British Medical Journal 324 : 393-396.
- - Donald A & Muthu V (2002) No evidence that MMR vaccine is associated with autism or bowel disease. Clinical Evidence, 7:331-40
Is there such a simple list in existance?
Interverbal compiled one a while back. It probably does not contain the latest studies, which are many.
There are here.
Whoa! Joseph thanks for the link! Also, you seem to have quite a specialized blog there. Good work.
Thanks all who have given bibliographic citations. I'm a medical librarian and I think this is going to have to be my own personal mission--to create a regularly updated, complete-as-possible bibliography of studies. Maybe it can be used for some meta-analysis eventually. Not that it would ever prove anything to the conspiracy thinkers, but at least I'd know who they were compared to the merely poorly-informed.
No matter how comprehensive the study, I doubt that the Daily Mail will be entirely satisfied.
What really annoys me is that when my own daughter had her shots recently, the nurses had to ask me questions about MMR, etc, just to make sure that I understood what was going on. Another waste of time thanks to Wakefield. Fortunately, the nurses reported that nobody had refused to have the vaccination, so there is hope.
It shouldn't be too long before members of the vaccines-cause-autism Illiterati begin to "spin" this study (if they haven't already), pointing out its "flaws" and potential "biases" of the researchers (e.g. "The author once received funding from a company that makes vaccines." - seriously, they consider this to be a real conflict of interest!).
All of their "spinning" and "rebuttals" and "dissenting opinions" amount to this:
Rearranging the deck chairs on the Titanic.
Yep, the vaccines-cause-autism ship is going down by the bow and these folks don't have the common sense to get into a lifeboat and row away.
Of course, they will argue that, "It's not sinking, that's just a little condensation in the bilges.", but everyone else can see that they're going under.
How many studies will it take for them to see reason and just walk away? I don't think that some of them will ever see the light. They'll be at the bottom, with 13,000 feet over water overhead, still saying, "No, it's NOT sinking, that's just a heavy mist."
And they'll curse you for being part of the conspiracy.
Thank Orac for reading these, let's face it, boring studies and summarizing them. Which is more than can be said for the mercury militia.
I have been reading the reactions of the anti-vaxers, of course they aren't accepting the results of this study and they are calling for new studies.
It seems what the anti-vaxers want now (and I am paraphrasing) is a clinical study of those children whose autism their parents believe was caused by the MMR vaccine, not funded by Big Pharma or the government and not carried out by anyone with connections to the pharmaceutical industry or government health organizations.
What exactly this clinical study would look for I don't know- I am assuming they want to see measles virus antibodies in the guts of autistic kids. Blood samples won't do.
Bill, it is called "moving the goal posts." No matter how much evidence shows the anti-vaxers where they are wrong, they will find some nit-picky reason to dismiss it.
Also, note the bit about the "gut connection". Richard Barr (a lawyer) went hunting for a doctor to do research to help support a set of lawsuits. The doctor he found who was willing to be paid for specific results turned out to be a gastroenterologist. That is probably only reason that so much is focused is on intestinal issues. If Mr. Barr had found a dermatologist to do his "research", the anti-vaxers would be focusing on skin problems caused by the MMR in autistic children.
Also, do not forget, the MMR vaccine in question was approved for use in the USA in 1971. You'll see in this paper that Wakefield even fudged that date:
What the anti-vaxers and mercury militia want is BFM (Big Funding Money) given to their favorite Woo researchers such as Haley, Wakefield, Geier etc, you know the ones I mean. They think if the woo researchers do the studies they will have a conclusion leaning towards their own beliefs. They also believe their "lobbying" for these off the wall studies will be a way of "paying back" these wonderful researchers who have stood by them all these years.
The parents of autistic kids would be much better off lobbying for money to be spent on helping them cope with their kids condition, rather than another wild goose chase study.
The Grauniad also published a thoughtful leader (opinion) piece, From science to conscience:
As the philosopher Karl Popper argued, the hallmark of scientific theorising is that it can be falsified by new evidence. After all, understanding only advances when people learn from their mistakes. Even before today, it was abundantly clear that the once-postulated link between [MMR] on one hand, and autism on the other, could not be sustained. ...
If MMR really was causing autism in some children, this unlucky minority might have been expected to have fallen victim to some peculiar reaction. But the authors followed more than 200 children who had been given the jab and found no sign of difference in the levels of viruses or antibodies between autistic children and others. So the evidence is now clearer than ever that the causal link does not exist. The reality, however, is that this may not alter the views of some who still insist MMR is a threat, for their thinking was never scientific and so is not amenable to the developing facts.
There are those who are instinctively hostile to technology .... Last, but not least, are those with a vested interest in continuing to spread the mistrust. Dr Andrew Wakefield ... is currently before the General Medical Council on various charges, some relating to whether his work has been financed in ways that could have compromised his objectivity. ... [I]t is already clear that much of the media has stoked up unfounded fears on the irresponsibly selfish grounds that sensationalism sells.
... [M]ore serious than the fear was its practical consequence - one child in five was denied vaccinations they needed, some of whom became ill. The MMR-autism debate is no longer a live question of science. Those still arguing otherwise must understand that it has become a question of conscience instead.
The reader comments in reply range from the thoughtful to the rabid.