The worst scientific idea of the decade: vaccines cause autism

The year and the decade are coming to an end, and top-10 lists are everywhere. These are hard to put together if you want to do it right. I’m opting for a simpler list: the top 1, and I’ll make it for the entire decade.

Of all the bad science, bad medicine, and pseudoscientific nonsense that human beings have come up with over the past decade, which is the worst? Of course, scientists have bad ideas all the time, and most of them never make it out of the lab. So for me, “worst” means a bad scientific notion that has emerged into the public domain and done more damage to civilization, or to public health, than any other idea of the past decade.

To answer this question, I wanted a belief or practice that rose to prominence during the past 10 years, which eliminates a large number of pseudoscientific practices and quack treatments that have been around much longer, including acupuncture, chiropractic, and homeopathy. So what idea has taken hold only recently?

And the worst scientific idea of the 2000's is: vaccines cause autism. This idea has caught on and spread like wildfire during the past ten years, thanks largely to the well-funded, well-publicized efforts of organizations such as Generation Rescue, led by the notoriously mis-informed celebrities Jenny McCarthy and her even more famous boyfriend, the actor Jim Carrey.

Strictly speaking, this terrible idea was first published more than a decade ago, in a now-discredited, notorious 1998 paper in The Lancet by Andrew Wakefield, a British gastroenterologist. This very small study of 12 children seemed to show a link between the measles, mumps, rubella (MMR) vaccine and autism, but it later turned out that the study had multiple flaws: Wakefield recruited the children to the study through a lawyer who was trying to build a case against vaccine makers, Wakefield himself received over $750,000 in consulting frees from the same lawyer, Wakefield didn’t tell his co-authors any of this, Wakefield had filed for a patent on an alternative, “safer” vaccine, and on and on. Although his co-authors repudiated the paper publicly and withdraw their conclusions in 2002, Wakefield has continued to this day to stand by his original claims. (See journalist Brian Deer’s website for a good summary of the Lancet scandal.) He moved to the U.S. after being forced out of his job at a London hospital, and he set up a private business in Texas from which he continues to promote his anti-vaccination claims.

If this had been like most bad science, the person who thought of it (Wakefield) would have done some studies, discovered that the idea had no merit, and that would have been the end of it. Who knows how many terrible ideas quietly die this way? That’s how science is supposed to work. But instead, thanks to a compliant media that is only too happy to publish sensational, scary claims, or to give air time to photogenic former Playboy models, the idea took hold and spread. As a result, millions of parents have refused to vaccinate their children, and many continue to do so. The original fears about the MMR vaccine have spread in the public mind, which now has unjustified fears about all vaccines. Reports in the U.S. and the U.K. show a frightening decline in the number of children being vaccinated for whooping cough, meningitis, and other diseases as well as MMR. And recent reports in the U.S. make it clear that the number one reason why people aren’t getting the H1N1 flu vaccine is a concern about safety.

As the MMR-autism fears spread in the early 2000’s, scientists realized that this represented a serious threat to public health. So even though there wasn’t an ounce of positive data showing that vaccines causes autism, dozens of studies were launched to test this hypothesis. Now, 10 years later, we can look at data from well over 500,000 children that conclusively shows that vaccines do not cause autism. (See the bottom of this post for a few examples.) In the U.S., the Institute of Medicine wrote a series of reports that made this same conclusion, as I’ve written previously.

Why did this bad idea take hold? Obviously, Andrew Wakefield has to shoulder much of the blame, but he struck a nerve that apparently resonated with many parents. But many other anti-vaccionists have poured money and time into spreading the anti-vaccination fears, and these people deserve at least as much blame. First, there is J.B. Handley, a wealthy businessman who founded Generation Rescue, which has been wildly successful – unfortunately – at spreading the anti-vax message. This group organizes rallies, takes out full-page ads in major newspapers, and sponsors conferences all supposedly intended to help find a cure for autism – but in reality they have pushed a wide variety of bogus theories and equally bad treatments.

But J.B. Handley really hit the jackpot with Jenny McCarthy, a former Playboy model and MTV hostess whose son was diagnosed with autism. McCarthy, who has the scientific credentials of a doorknob, decided that vaccines were the cause of her son's autism, and she went on a publicity rampage that continues to this day. She regularly appears on TV shows such as "Larry King Live" to promote this claim, and seems to relish having shout-fests with doctors whom Larry King brings on the show for “balance.” After she started dating actor Jim Carrey, he joined the cause, and together they have been so effective that Generation Rescue has now re-branded itself as “Jenny McCarthy and Jim Carrey's Autism Organization.”

Despite dozens of well-conducted scientific studies refuting this terrible idea, millions of parents continue to withhold vaccines from their children, threatening society with the return of diseases that we had under control. As Ann Schuchat of the CDC recently said in testimony before Congress, “The public's confidence in our vaccine system is very, very fragile."

The mistaken idea that vaccines cause autism now has a death toll associated with it, as children in the U.S., the U.K., and other countries have died from measles, Haemophilus influenza, and other childhood diseases for which we have effective vaccines. By one estimate, Jenny McCarthy’s campaign against vaccines has killed over 450 children and sickened over 50,000 - and the toll continues to rise. McCarthy's response? She said:

“I do believe sadly it's going to take some diseases coming back to realize that we need to change and develop vaccines that are safe. If the vaccine companies are not listening to us, it's their fucking fault that the diseases are coming back.” (Time magazine, April 2009)
No, Jenny. It’s your fault.

Vaccines are probably the single greatest boon to public health in modern times. It’s appalling, and frightening, that a telegenic former model, aided by the media (particularly awful offenders are Larry King and the Huffington Post) and a handful of bad doctors, can wage such a successful campaign against a medical advance that has saved hundreds of millions of lives. Like many others, I wish this idea would just go away, but we will probably have to struggle against it for years to come.

Finally, I have to point out that several other journalists and bloggers have included this idea on their “worst of the decaade” lists:
1. Orac at Respectful Insolence made the same point (and beat me to it).
2. Clive Thompson in the Washington Post, in its top 10 worst ideas of the decade list
3. Noted vaccine expert Paul Offit, writing in Newsweek on the top 10 most overblown fears of the decade

For those who want to see some of the scientific studies, here’s a small sample. All of these studies support the same conclusion: that vaccines do not cause autism:

Peltola H, Patja A, Leinikki P, et al. No evidence for measles, mumps, and rubella vaccine-associated inflammatory bowel disease or autism in a 14-year prospective study. Lancet, May 2 1998, 351(9112) p1327-8.

Madsen KM et al. A population-based study of measles, mumps and rubella vaccination and autism. New England Journal of Medicine 2002; 347: 1477-82. (Involved over 500,000 children born in Denmark, and concluded “This study provides strong evidence against the hypothesis that MMR vaccination causes autism.”)

Honda H, Shimizu Y, Rutter M. 2005. No effect of MMR withdrawal on the incidence of autism: a total population study. Journal of Child Psychology and Psychiatry 46(6):572–79.
(Involved over 300,000 children in Japan and concluded that MMR was “most unlikely” to be a cause of autism.)

Mrozek-Budzyn D, Kieltyka A, Majewska R. Lack of Association Between Measles-Mumps-Rubella Vaccination and Autism in Children: A Case-Control Study. The Pediatric Infectious Disease Journal: 1 December 2009.


  1. Great summary. Accurate and well-written.

  2. Thanks for the summary. Was it actually $750,000 or $75,000? I wasn't sure.

  3. PenguinSix: it was 435,643 British pounds, which at the time was over $750,000 US dollars.

  4. I think the anti-vaccine movement needs to be considered in the context of the more general anti public health movement. Maybe it is more of an issue here in California than the East Coast, but there is also a movement against pasteurization of milk. Probably not as much a danger as the anti-vaccination movement, but again, it is based on ignorance of the 19th century health hazards that science has freed us from.

  5. It was $750,000. And had Wakefield at any time failed to criticise MMR, his status as an expert in the litigation would have ended, and his money would have been stopped.

  6. Wow. I had read it as $75,000 and thought that was just obscene, but $750,000 is beyond even that, borderline criminal.

  7. It is one of the reasons the vaccine for the new H1N1 flu was so late. For the sorry details see Basically the government knuckled under to these people.


  8. If vaccine side effects have, as purported by my GP, been eliminated and are now "safe as houses', why is it impossible for me to obtain a full ingredients listing of said vaccines from said GPs ( in Australia)?What is there to hide? His response..." you probably wouldn't understand what they were anyway"....didn't exactly meet with wholehearted accord on my I chose not to vaccinate my baby.
    This man was a leading pediatrics doctor and if this is a prima facie example of contemporary professional medical practice, no wonder educated, discerning consumers are getting jack of arrogant, imperialistic practices best suited to the era of Mad Men when smoking was recommended by the best doctors of the day!!

  9. Anon: vaccine ingredients are not secret, and it's too bad your GP didn't just give you a list. He shouldn't have been so condescending.

    The CDC in the U.S. has a webpage with a long list of ingredients covering almost all vaccines, at this site:

    In addition, the package insert lists the specific ingredients for any one vaccine. Your GP should be willing to show you the insert and give you a copy. I hope his behavior isn't typical of GPs in Australia.

    I hope you'll reconsider vaccinating your baby. If your child ends up with measles, or polio, or meningitis, he/she could suffer permanent harm. The vaccines are very, very safe.

  10. Well the same thing happened to my friend whose 6 month old had her vaccination and a week later she had a seizure. It was discovered she had a genetic predisposition to these, however when her mother asked whether the vaccine could have triggered it, her GP also wouldn't reveal the contents of the vaccine. Which I'm afraid does look kind of suspicious on the face of it. I just did a bit of searching and found the official report on the recently released swine flue vaccine which is exactly the kind of info I want on children's vaccine. Listed are trace elements of egg albumen ( the child is allergic to egg) and a fungicide which I found can have side effects akin to convulsions in susceptible individuals. As I can only surmise that these nonactive ingredients are in most vaccines it would seem possible that they may act as a trigger in certain people - and it would seem reasonable for a mother armed with the appropriate information to choose not to vaccinate in the light of this info. So I suspect if GPs are not able to release this info it would seem that they don't want people making tangible links between side effects and vaccination. I also tried to click on your link and it just took me back to your home page - I shall try cutting and pasting. Maybe a government block! I hope not, anyone would think we lived in China! (she scoffs with only a hint of irony).

  11. Anon: sorry about the link, I'm not sure why the html got messed up, but here it is again: I assure you it's not a government conspiracy.

    About the egg proteins: this is well-known, and any GP should tell you, but it is unique to the flu. The flu vaccine is grown in eggs, unlike any other vaccine. It's a 50-year-old technology and I've blogged about this before; it is long past time we replaced it with more modern methods, which would be much faster and cheaper. Because of this, people with egg allergies should not get the U.S. flu vaccine. Some vaccines produced in Europe use a more modern method that doesn't use eggs, but those are not available in the U.S.

  12. Steven: I can't thank you enough for your articles and support of vaccination. I have found that physicians, regardless of their specialty can be very condescending regarding patients intelligence and as you have already explained the contents of any vaccine have many sites/resources including the manufacturers websites, as well as the prescribing information the physicians have in their fridges (where they store vaccines). Based upon some of the comments it is clear some people are more willing to believe misinformed celebrities, unsubstantiated websites & conspiracy theories. Keep up the great work and do your best to go on Oprah Winfrey, Larry King etc. to provide the truth to the gullible public.


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