This guest post was written by Allison Hagood, who originally published a version of it on the Facebook page for Your Baby’s Best Shot, a science-based book on childhood immunizations she co-authored with Stacy Minzter Herlihy.
This post is the first in a Red Wine & Apple Sauce series called “Epidemiology 101.” While it does not explain a specific epidemiological concept, it makes clear how a mythical study often demanded by anti-vaccine propagandists would not be possible when abiding by the standards of quality epidemiological research.
Multiple studies in multiple countries using multiple research models and multiple research groups, with multiple funding sources, have found no link between vaccines and autism. They have also found no links between vaccines and a long list of other conditions, such as ADHD, asthma, diabetes and auto-immune disorders, that anti-vaccine propagandists attempt to link to vaccinations.
These studies have been dismissed by those anti-vaccine propagandists as having the wrong funding source, the wrong research design, the wrong focus, not separating out antigens from other vaccine ingredients, separating antigens from other vaccine ingredients inappropriately, not testing this or that, or some other reason that likely lacks validity.
Meanwhile, those in the anti-vaccine movement want ONE study. The One Study To Rule Them All. The One Study that tests every possible aspect of every vaccine and finds them all, together and separately, through this One Study, to be completely effective and completely safe for all children and not linked to any conditions.
Basically, anti-vaccine propagandists are asking for the following (they may not realize that this is what they’re demanding, but the expectations of valid research design would require these conditions):
1. Eliminate the use of all vaccines immediately in every country on the planet. Immediately — regardless of any public health concerns that exist.
2. Randomly sample an acceptable number of children with similar characteristics for an experimental group and a control group for each of the group configurations discussed below (in #4).
The numbers in each group would need to be in the hundreds or thousands to satisfy statistical requirements for validity and significance, and would have to include children from every country, every ethnicity, every socioeconomic status, with every possible genetic combination from parents, and of every possible health history based on parental family health. (It is a common tactic of anti-vaccine propagandists to claim that such-and-such vaccine can be a problem for children with this or that genetic make-up or some other characteristic – they frequently move the goalposts in making this argument – so the One Study would need to account for all those potential variations.)
Anti-vaccine propagandists have rejected studies with 3,000 or more participants, so each group below would likely need to contain huge numbers in order to satisfy them. (But then again, many of them accept 12 subjects – the number in Andrew Wakefield’s fraudulent and retracted case study – as valid, so who knows?)
Anti-vaccine propagandists are fond of saying “There are plenty of unvaccinated kids already, so just use them!” However, researchers cannot use pre-existing groups who selectively vaccinate or do not vaccinate at all because research has shown that families that don’t vaccinate differ from families that do vaccinate, and those pre-existing differences would be a confounding variable in the study. That is, it would be impossible to tell whether any conditions or differences in effects in the children occurred because of receiving/not receiving vaccines or because of the other inherent differences between families who do and families who don’t vaccinate.
To do a credible study of the kind that the anti-vaccine propagandists are demanding, then, researchers MUST randomly sample children and then MUST randomly assign them to the groups below. Parents would therefore have no choice about whether their children were assigned to a group receiving vaccines or a group not receiving vaccines.
3. Obtain permission from parents of children in each group to administer an injection into their child. The parents and children will not know what injection the child is receiving. The parents would not be allowed to have their children receive any injection from any other source, to avoid contamination of the data. Some children in the study would be completely unprotected from any disease outbreak, and their parents would be unaware of whether or not the children were unprotected.
4. The injection received may contain any of the following configurations:
a. Just saline. This comparison (or “control,” in scientific terms) group would be necessary for every single group involved in the study. No one in this group would receive any ingredient of any vaccine ever, just injections of saline.
b. Just the antigen, in saline. (An antigen is the inactivated pathogen – the virus or bacterium – or portions of it, or a weakened version of the live pathogen, which the body recognizes as an intruder and causes the immune system to build up the white blood cells that could fight the real deal later on.)
c. Just one ingredient of the vaccine (e.g., formaldehyde), in saline.
d. Two or more of the ingredients, in various combinations (e.g., formaldehyde and the antigen, formaldehyde and the aluminum salts, the antigen and the aluminum salts, etc.). For example, according to the CDC pink book, the MMR-II (measles, mumps, rubella) vaccine contains these ingredients:
ii. amino acids
iii. fetal bovine serum
v. sodium phosphate
vii. recombinant human albumin
x. hydrolyzed gelatin
xi. chick embryo cell culture*
xii. WI-38 human diploid lung fibroblasts*
*These two items are not actual ingredients present in the final formulation of the vaccine, but they are used in the production of it, and, presumably, those calling for this sort of study would want to see “evidence” that using these ingredients during the course of vaccine production is not “unsafe.”
So, starting with the first ingredient on the list, researchers would have to have a group that received every single vitamin injected, every single vitamin in combination with every single other vitamin, in combination with multiple of the other vitamins, etc. Let’s say there are four different vitamins (A, B, C, D). There would have to be an A only group, a B only group, a C only group a D only group, an A/B group, an A/C group, an A/D group, a B/C group, a B/D group, a C/D group, an ABC group, an ABD group, an ACD group, a BDC group, and an ABCD.
That’s 15 comparison groups for four ingredients – and that is only for the vitamins, one of the 12 ingredients in the MMR vaccine (not including any part of the actual measles, mumps or rubella viruses). Then, researchers would have to include a group for each vitamin in combination with each other ingredient – vitamin A combined with sucrose, B with sucrose, D with sucrose, etc. Then each ingredient would have to be tested in various combinations with other ingredients. This would add up to thousands of groups, each having hundreds or thousands of children to cover all combinations mentioned above.
The above breakdown of possible combinations would have to be repeated for every vaccine, for every booster and for every possible combination of boosters.
5. Researchers would be expected to follow every single child in every single group throughout the course of their entire lifetime (which, with current life expectancy, can be 70-80 years in developed countries), monitoring every medical/health condition that develops, and comparing the rates for those conditions between each and every group above. If one of the thousands of study groups lost a single participant (through moving, withdrawal, death, etc.), then anti-vaccine propagandists would declare the study null and void, even though such attrition is to be expected, and is controlled for in the study design.
6. For each and every group mentioned above, a control group would have to exist, in which the children received no injection at all, of anything. No saline, no antigen, nothing.
7. Remember that the anti-vaccine movement wants each vaccine tested individually, THEN see the vaccines tested in combinations. So, one generation of children would have to receive the above breakdown of ONE vaccine over an entire lifetime, then another generation of children receiving the above breakdown of ANOTHER vaccine over an entire lifetime, etc., until all vaccines have been tested individually. (It’s unlikely that enough children in one generation would exist to meet the requirements of all those groups for each individual vaccine, so the complete study would require multiple generations.)
Then, and only then, do researchers start testing vaccine boosters. Then after that, they test vaccines in combinations, but only two at a time. Then three at a time. This requirement would mean that the study that would fit the criteria demanded – the One True Study – would last until approximately the heat death of the sun.
We haven’t yet discussed the ethics of the various groups (spoiler: It wouldn’t pass muster with any ethical board), the sampling difficulties or the enormous amounts of money that would be required (money that could not come from any government, any governmental agency, any institution of higher education or any scientist who’s ever done vaccination research in their career).
At this point, it should be apparently that such a study is not possible.
It’s also not necessary.
Various studies have addressed various aspects of each of the embedded questions in the above scenarios, and in combination, those answers address the concern of the anti-vaccine movement. For example, aluminum salts (not elemental aluminum, as is claimed) are one ingredient used in vaccines. These are used as an adjuvant, a substance that induces a stronger immune response so that less antigenic material is required. The safety of this particular adjuvant has been well established. That’s just one meta-analysis of the studies of the safety of one ingredient. It’s not part of The One Study that anti-vaccine propagandists want, though, so they reject it.
Meanwhile, there are other meta-analyses about aluminum salts, and about other adjuvants and about all the various other ingredients in vaccines, not including the clinical trials that the vaccines went through before licensure and the many post-licensure studies about individual vaccines and about combinations of vaccines.
Think of all these studies – thousands and thousands of them – as a jigsaw puzzle. The puzzle isn’t one piece. It is composed of many pieces that fit together, creating a complete picture. The big picture on vaccinations is that they are safe and save lives. For individuals with conditions counter-indicating one or more vaccines, studies have already identified those conditions and the risks to guide clinicians. More studies are being done all the time to keep an eye out for developing risks.
Science is a process. Science is not about The One Study. It’s about ALL the studies.