Racing for Progress
Concern Grows in the British Media About Swine Flu Vaccine

Observational Vs. Experimental Studies for the Autism Vaccine Question

ObsExp By Catherine Tamaro

After reading Katie Wright’s summary of the August 3 Senate Committee on Appropriations’ hearing on autism (HERE), I would like to comment on Dr. Insel’s testimony to Senator Harkin on why a study comparing vaccinated vs. unvaccinated children has not been done to date.  Dr. Insel claimed that such a study would be “unethical” because, as he apparently envisions it, the study would entail dividing a large cohort of newborns into two groups, vaccinating one cohort but not the other through age two, and then comparing outcomes.  This is just a bit disingenuous and I would like to explain why.
Research studies are divided into two categories, observational studies and experimental studies.  An observational study observes individuals and measures variables of interest but does not attempt to influence the responses.  (The “epidemiological” studies to which Dr. Insel refers are actually observational studies.)  An experimental study, on the other hand, deliberately imposes some treatment on individuals in order to observe their responses; the purpose of an experiment is to study whether the treatment causes a change in the response.   

All studies done to date investigating a correlation between vaccinations and autism have been observational studies, but no observational study has been done comparing the prevalence of autism diagnoses in a vaccinated human population compared to an unvaccinated human population. When Dan Olmsted points out that he has identified large populations of unvaccinated children in the United States and asks why a study has not been done on them, he is actually asking why an observational study has not been done.  When Senator Harkin asks Dr. Insel why a study has not been done on vaccinated vs. unvaccinated American children, he too is actually asking why an observational study has not been done to date.  Dr. Insel, however, chooses to respond by saying that an experimental study would be required in order to resolve the issue.  Given that it is unlikely Dr. Insel rose to the top of the NIMH without learning the distinction between observational and experimental studies, we can only assume that he knows quite well what is being asked of him and is actually responding to the question “Why hasn’t a study been done” with a response of “Because we’re no interested in doing it” – with a little bit of technical bluff to remind the nonscientists at the hearing that they don’t understand “science.”

I would like to point out the epidemiological similarity between smoking/lung cancer and vaccines/autism.  Smoking has been proven to cause lung cancer, yet not a single experimental study on humans was ever done – all of the human studies proving that smoking causes lung cancer were observational.   The experimental studies were performed on research animals only.  Attached at the end of this letter is a lesson taken verbatim from an introductory course in college statistics describing how the connection between smoking and lung cancer was made.

Thus what Dr. Insel doesn’t say is that the NIH has chosen to forego all experimental animal studies on vaccination effects and all observational studies comparing populations of vaccinated vs. unvaccinated human children, under the guise that any study demonstrating a link between vaccines and children necessarily involves experimenting on children.  From a statistician’s perspective, however, these kinds of studies could be performed easily, with no need whatsoever for experiments to be performed on children.  The staff at NIH clearly have the expertise, the resources, and the funding to mount such studies – if they wanted to do them.   But as Dr. Insel insinuates (but doesn’t quite come out and say), the fact is, they don’t want to.  His testimony is misleading and disingenuous and I sincerely hope that the next time he (or anyone else from NIH) is questioned about why the NIH hasn’t commissioned any studies on the effects of vaccination, he is pushed to give a more responsive answer.

Supporting Causation Without Experimentation

1. Strong Association
2. Association consistent across studies
3. Higher doses associated with stronger responses
4. Alleged cause precedes the effect in time
5. Alleged cause is plausible

More criteria met → Stronger case for causation

Smoking and lung cancer

Without ever experimenting on human subjects, U.S. Surgeons General have long stated that smoking causes lung cancer.  This statement can be made because the relationship meets the criteria for establishing causation.

1. Very strong measures of association between smoking and lung cancer found in observational studies.
2. Multiple studies show same outcome across time and geographic boundaries.
3. Heavy smoking has greater risk than light smoking.
4. Smoking predates contracting lung cancer.
5. Connection between tars and lung cancer has been proven in animal experiments making cause plausible.

Source:  The Basic Practice of Statistics, Fourth Edition, pub. 2007, by David S. Moore.  W.H. Freeman & Company, New York.

Catherine Tamaro has two sons, one born in 1996 and diagnosed with ASD at 3-1/2, the other born in 1998 and NT with colitis.  She has a degree in mechanical engineering and lives in WA.  She moderates the Vitamin K Yahoo list.



the main point is that an experimental study can easily, and ethically be done. There are thousands of parents forgoing vaccines for their newborns. the doctors evaluating the children for autism don't have to know whether or not the children received vaccines - his evaluations would be blind...and also - stopping a study at 2 yrs old is absolutely worthless. many of us have autistic kids that didn't begin exhibiting symptoms until after 4 yrs old (or after Kindergarten shots) - just look at Tanner.


Steve D, my favorite commenter! Not.

Mayer Eisenstein's practice is *not* the only pool of unvaccinated children. Frequent media reports highlight the presence of unvaccinated children all over the country (like, oh my God! these crazy people in California mentioned in the NYT recently: "Public Health Risk Seen As
Parents Reject Vaccines," by Jennifer Steinhauer, March 20, 2008. Your statement is nearly as foolish as the ones from people who think the Amish are the only Americans who don't vaccinate their children. An observational study could be done. The voices calling out for such a study are diverse and well-respected: Bernadine Healy, Carolyn Maloney, Chris Smith, Tom Harkin, etc. They are Democrats and Republicans; medical professionals, parents, and politicians--in short, they're anyone who has a little intellectual curiosity and who doesn't stand to lose big money if our current vaccine schedule and formulation are shown to be harmful.

Kathy Blanco

Even if you had an unvaccinated population, I would venture that they are not truly UNvaccinated, due to their parents mutagenic vaccines in their generation...therefore, is any generation of children who are unvaccinated, truly UNvaccinated? My thoughts on this may be, that parental vaccines do affect their offspring...however, it has a lesser affect, if the child was not vaccinated, as opposed to vaccinated, and further mutations occur. Why won't we include in this study IF THE PARENTS are vaccinated....which in my estimation are in higher amounts...this would show a continual viral infection could possibly occur in their subsequent children from their vaccine series...knowing full well, that may complicate this research, it begs some questions as anyone who says, my child still got autism, without vaccines, may be not so unvaccinated as they seem?

Harold L Doherty

Contrary to Dr Insel's testimony (and Steve D's opinion) Dr. Bernadine Healy, Dr. Julie Gerberding,and Dr. Duane Alexander have all said that observational/comparison studies of vaccinated and unvaccinated populations could be done.

Bob Moffitt

Steve writes:

"The author seems to miss the point that observational epidemiological studies to date have not supported any link between vaccines and autism, unlike the very strong association between cigarettes and lung cancer."

My friend, you may have missed a few points yourself.

First of all, thanks to Julie's excellent overview of the fourteen studies...there has not been one "observational epidemiological" study done "that was not completed and/or funded by someone who manufactures, patents, endorses, promotes, administers, defends in a court of law, and/or profit from vaccines". NOT ONE.

Which questions your observation:

"unlike the very strong association between cigarettes and lung cancer.

In my opinion, it is a little disingenious to suggest the independent cigarette studies you allude to should be considered as reliable as the studies done by public health officials responsible for recommending and approving the vaccines...vaccine manufacturers who make and profit from them...or...the pediatricians who administer them.

I would also question your observation that overcoming "selection bias among ... vaccinated and unvaccinated" groups presents a scientific research obstacle that is "virtually insurmountable".

As difficult it may prove to be, saying it is "virtually insurmountable" does not make it so.

Surely, even you will agree, parents rightly expect public health agencies that promote aggressive childhood vaccine policies .. be competent enough to overcome whatever obstacles they confront to conduct, INDEPENDENT, SCIENTIFIC, irrefutable research studies that prove their vaccines are as "safe and effective" as they insist they are?

Nothing less than a "vaccinated vs unvaccinated" study will provide such irrefutable evidence on vaccine safety.

Steve D

The author seems to miss the point that observational epidemiological studies to date have not supported any link between vaccines and autism, unlike the very strong association between cigarettes and lung cancer.
The author also fails to acknowledge that selection bias among the two groups in her conceptual "vaccinated v. unvaccinated" study is a virtually insurmountable confound, a fact that makes Dr. Insel's position make a bit more sense.
In other words, the only way to remove the selection bias problem (for example, comparing a host of Dr. Eisenstein's kids to a random slice of American kids) is to randomize and double-blind.
Hence the need for an experimental study.


What EXCELLENT points!! And SO clearly stated!!


Not sure of reason for this sell off /

Perhaps Mr. Gates might see some flaws with these firms... I am sure he wants to use his Foundation funds in a productive manner.

From the Wall Street Journal

Gates Foundation Sells Off Most Health-Care, Pharmaceutical Holdings


SAN FRANCISCO -- The Bill and Melinda Gates Foundation, the world's largest private philanthropy fund, sold off almost all of its pharmaceutical, biotechnology and health-care investments in the quarter ended June 30, according to a regulatory filing published Friday.

The Seattle-based charity endowment, set up by Microsoft Corp. founder Bill Gates and his wife, sold its total holding of 2.5 million shares in health-care giant Johnson & Johnson in the quarter, according to the filing.

The foundation also sold millions of shares in major drug makers, including 14.9 million shares in Schering-Plough Corp., almost 1 million shares in Eli Lilly & Co., 8.1 million shares in Merck & Co. and 3.7 million shares in Wyeth, over the same time period. The foundation no longer holds shares in any of those companies......

Autism Grandma

Even with all of the studies that already exist demonstrating that vaccines are dangerous and have produced all kinds of health issues including deaths, and even with all of the studies which relate to vaccine induced autism, the final undeniable proof is going to be the vaccinated versus unvaccinated study. The government agencies know this and the vaccine industry knows this. All of the evidence demonstrates that there is a definite conspiracy to prevent this study from happening. [Yes, it is a CONSPIRACY]


What about a university study utilizing statistics course students? This would produce legitimate unbiased results with the majority of labor being accomplished at no cost. University students participate in all kinds of study related programs. I don't know if this is the answer, but THERE IS AN ANSWER. And if the autism community does not find that answer, this study is NEVER going to happen.

Kathy Blanco

They will never admit their why don't we scare the crap out of them and finally say it, we ARE anti vaccine...just thinking.,...??? (I do agree everyone has a choice, but as for me, I am never going to trust a white coat again)...sigh....


Here is my idea for a Vaxed/Unvaxed study, which I think is very straight-forward and
did not require the genious which I don't have
to come up with:

You take 10,000 exempted kids from all over the country. No use checking for autism among
those kids, because of a huge selection bias due
to the fact that they are in normal schools. But what about their younger brothers? If you
find in the state records 2,000 younger brothers of exempted kids, you should be able to find at least 10 with a more severe
form of autism. if you find 2,000 younger brothers of exempted kids which are already
school-aged, you only need to check wether
they are in normal classes to know that they
don't have a more severe from of autism. The
number of kids you would have to assess is very small.

So how about it, autism community?

Bob Moffitt

Jim Smith states:

...If there were such a large effect of vaccines as you purport, it would have been obvious by now...

Some things are more than just "obvious".

Such as...we know for certain...the CDC and AAP (1970's)dramatically increased the numbers of vaccines they recommend for children from 23 doses of 7 vaccines by age's)48 doses of 14 vaccines by age 6.

We also know for certain the dramatic increase in autism "coincidentally" matches the dramatic increase in childhood vaccines..and..there is the likelihood that 1% of this generation, the most heavily vaccinated generation in our nation's history, are now on the Autism Spectrum.

We also know for certain...because the CDC has told us so...that 1 in every 6 American children suffer some childhood development problem, such as, allergies, asthma, juvenile type 1 diabetes, juvenile rheumatoid arthritis, ADD, ADHD, etc....which were far less common in all previous, less vaccinated generations?

With all due respect, what will it require to make the connection "obvious" to you?

Out of Africa

Jim, -- just 25 million to collect the data for vaccination records? Hillary Clinton just proposed 17 billion to stop rape in the Congo. While I think that's an extremely serious issue and before autism came into my life, I would have thought it one of the top priorities in the world, I have another idea. For seventeen billion dollars in research funds for a vaccinated/never vaccinated study and vaccine safety review, I'll go to the Congo and stand in for the victims. I'm sure I could find other bidders among autism moms. Some could bid broken limbs, others cracked teeth or head injuries. For seventeen billion, I'm sure many of us would agree to any form of torture short of death, immobility or AIDS, simply because we have to stay alive and at least somewhat mobile for our kids.

For the record, I find nothing remotely attractive about being gang raped and beaten with a rifle butt, but if that's what it took...

Benedetta Stilwell

I saw it too and I already did write Rosenbloom.

James I worked in tobacco from the time I could pull plants out of the bed at 4 years old right on up till I was 25. through all those years We all knew it was bad for us and for those who would use it. We all knew it addictive, because my Dad and all my uncles were hooked on it, we all knew how they coughed, and we all knew of so and so that had come down with emphasemia or lung cancer. We all knew the tobacco companies was lying, and their studies were not worth the paper they were written on. This vaccine business has the exact same feel as the tobacco ordeal did back then. Government agencies helped the tobacco companies back then and they are doing it again with the vaccines. Only difference is nobody was forcing people to smoke although it did make you look cool and there were some studies that showed it might really be good for you!


Simple, beautiful, elegant logic and to the point. My brain is happier now that you've cleared up the issue that Insel works so hard to distort. Thank you.


I want to know how we can all get together and call for this man's resignation. We has the American people should have a say in who is the head of the NIH? Call this man to the rug in public. If I have to embarrass the man in public and show just how stupid/crass/ignorant/unconcerned with children's welfare he really would give me great pleasure. If this man (supposedly) doesn't know the difference between Observational Vs. Experimental Studies, then HOW on earth did he make it into his position? I don't know about any of you but I'm sick to death of these people playing the "I'm so sorry. I just don't understand what you're saying." thing. The whole playing DUMB thing is getting old. I should say it IS OLD. If Mr Insel is the kind of man that is heading up agencies for the US then God help us all.


With the incidence now being a whopping 1% of children and 1 in 71 for boys, that puts the numbers very close to the chance of getting lung cancer and smoking as long as you are under the age of 60. and at the rate we are going it will be just a few years and autism will affect more children than lung cancer affects adults.I wish my son had had 60 years of simplicity and joy vs 1 1/2 and then being thrust into a nightmare that will continue in his life. As far as he have come, he will never not be "different"...and always struggle. The rate of autism/vaccine injury is greater than the rate of lung cancer under the age of 40.
Smoke and mirrors is all the autism/vaccine injury community receive from those we once relied on for transparency in caring for our children.


does anyone know the prevalence of lung cancer among smokers? i know my grandfather smoked a pack a day for decades and reached an old age without a diagnosis of cancer. of course, based on this experience i'll be encouraging my son to smoke cigarettes, especially if he wants to lose weight. & certainly, if the government mandates it as a prerequisite for public school participation.

Jim Moody

GREAT article! Insel also ducked the obvious observational study of looking at a RETROSPECTIVE vax vs unvax, say, 10-yr-olds [old enough to get confirmed DX's of childhood chronic illness]. No ethical dilemmas here, although care would be needed to avoid, e.g., adverse selection bias [only the healthy, or sick kids for that matter, signed up for the study]. Such a study could get very quick results, and would lead to prevention of vax-caused chronic injury through, e.g. changes in the schedule.

A double-blind prospective study would be the "gold standard," and such a study, the $4b. National Childrens Study is just beginning now. NICHHD Director Duane Alexander has publicly said that there may be as many as 5-10k unvax'd kids in the 100k-kid study, which would give wonderful results with statistical power. But I think he's been sadly misled. There are no protocols that I'm aware of to ensure that a sufficient number of unvax'd [religious and philosophical exemptions] are enrolled. Worse, medical/research quality vax and health records aren't even being collected and abstracted; the data are coming from questionaires. They say it would cost $25m to collect and abstract the "official" vax records. Thus, the $4b. will likely be a total waste for the vax issue.

As to a even a prospective "experimental," Insel actually has his ethics backwards. The intent of vax's is to confer a lifelong benefit by altering the human immune system, one of the greatest gifts of God and Darwin. It must be assumed, for ethical purposes, that there is risk of chronic harm that could be less than, equal to, or more than the chronic "benefit." The safety of the schedule - with respect to chronic adverse events - should have been, and continue to be demonstrated, in clinical trials. Absent a reasoned belief - supported with data - the schedule must be presumed by be UNPROVEN with respect to safety. Accordingly, it is unethical for the CDC to recommend and doctors to administer the schedule without, at least, warning that is unproven as to safety and therefore must be regarded as a mass population experiment. Even with such warnings, the unproven schedule may be unethical. So, Insel is completely backwards. He claims it would be unethical to deny "random" children the benefits of vax, but it would be at least as unethical to inflict on "random" children the [as yet completely unknown] damage from vaccines.

Finally, there should have been, and must be now, an ongoing research program in animals, especially primates, comparing the schedule to placebo. Again, no special ethical dilemmas here. These are the two research programs -- humans and animals -- included in the autism research plan last December and then unlawfully deleted last January in a carefully designed Kabuki play by Insel and CDC. The comment deadline for year two of the autism research strategic plan is coming up August 21 [], so the entire community must insist that the vaccine projects be reinstated immediately.

The REAL question is why is the rear guard of the public health elite -- and now Insel in particular -- absolutely obcessed with a policy of "deliberate ignorance" as to the health of unvaccinated children?

walter Constantine

As I read your post I am watching Fox News " House calls" I would like to say the Dr. on there said the vaccines are safe and all the studies show this.

I would like to ask people out here to e-mail "house calls" at fox news and ask the DR to read this article and the 14 studies.

Thank you

Heidi R

Catherine: Such a simple premise! This is Brilliant! Thanks for writing this!

James Smith: It IS obvious. Autism, ADD, ADHD, Asthma, Diabetes, Learning Disability, Life threatening Allergic reactions, Speech Delays, all increased dramatically right at the same time as the increase in the # of vaccines. There is a need for more research to clinch it and Insel and those like him stand in the way of that research.

Tanners Dad

Great article... How about charges of perjury? The anti us group is out in full force this AM... Seen this article twisting Autism Speaks position...

James Smith

Using smoking is not really a fair comparison. The association of smoking with disease is MUCH greater than for any alleged link of vaccines with autism. If there were such a large effect of vaccines as you purport, it would have been obvious by now.

candace passino

Insel also says the studies have been done..the more i watch this the madder i get..did someone give the seanator the 16 studies to go thru?and why is it ok with these people to exsperiment with the swine flu vaccination..they want pregnant women? children? this is insane..!!!candace

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