Over the past 20 years or so, I’ve read a lot of vaccine research studies. Most, published in top journals by real scientists, are worthy of respect. And they provide powerful evidence that vaccines are safe and effective. Of course, there are a handful of studies that are pseudoscientific garbage. Or retracted. But today, I think I’ve seen it all – a Spanish animal research team published a sheep vaccine study that they claim shows that the aluminum adjuvants in the vaccine altered their behavior. And you just know that the anti-vaccine religion will jump all over it as “proof” that vaccines are dangerous. Yawn.
In case you missed it, yes, this is a sheep vaccine study.
To be fair, I have no idea whether these researchers are part of the anti-vaccine religion – it’s possible that they think they’ve found something, but they do rely upon some discredited anti-vaccine tropes and falsehoods as the premise of their studies. Moreover, this article furthers the false narrative about aluminum in vaccines. And we’ll keep seeing it repeated on anti-vaccine Twitter and Facebook posts because the anti-vaccine zealots have nothing else.
The sheep vaccine study by Javier Asìn et al., published in Pharmacological Research, investigated cognitive and behavioral changes in lambs that had received repeated vaccination with aluminum-containing vaccines.
Let’s take a critical look.
Sheep vaccine study results
I’m not going to spend much time with the results, because I find it very troubling that the author’s conclusions are based on a total study of 21 animals, seven in each group. I laugh at clinical trials in humans that don’t contain 1,000 or more patients or epidemiological studies that don’t include a sample population over 100,000. An animal study that includes 21 lambs ranks near at the bottom half of the hierarchy of biomedical research.
The researchers put those 21 sheep into three equal groups:
A. Control group
B. Adjuvant only group
C. Vaccine with adjuvant group
I will get to a criticism below, but based on the small experiment, the authors concluded that:
Animals in groups B and C exhibited behavioral changes: affiliative interactions were significantly reduced and aggressive interactions and stereotypies increased significantly. They also exhibited a significant increase in excitatory behavior and compulsive eating. In general, changes were more pronounced in the Vaccine group than they were in the Adjuvant-only group. Some changes were already significant in summer, after seven inoculations only. This study is the first to describe behavioral changes in sheep after having received repetitive injections of Al-containing products, explaining some of the clinical signs observed in ovine ASIA syndrome.
Aluminum in vaccines
For those of you who are unfamiliar with aluminum in vaccines, aluminum adjuvants are added to vaccines to stimulate the immune response to the vaccine’s antigen – however, they do not induce any immunity to anything by themselves.
Aluminum adjuvants have been used for over 70 years in vaccines without any evidence that they cause harm. Unfortunately, these adjuvants have only become an issue for the anti-vaccine world because they keep running out of real science to support their beliefs about the safety of vaccines.
There are a few key points to be made about aluminum adjuvants:
- The amount of aluminum in vaccines (and remember, only a few vaccines have aluminum) is measured in micrograms. The maximum allowable amount of aluminum in a vaccine is 125 µg. Based on the recommended schedule of vaccines, the maximum amount of aluminum an infant could be exposed to over the first year of life would be 4225 µg (or 4.225 mg). Let’s put this into context – a newborn baby averages body burden of about 384 µg of aluminum. In addition, typical concentrations of aluminum in breast milk (10-49 µg/L), soy-based infant formula (460-930 µg/L), and milk-based infant formula (58-150 µg/L) mean that the dose of aluminum from these sources far exceed the dose of vaccines in just a few weeks. A baby also inhales several thousand micrograms of aluminum per day, unless they live in some bubble with ultra-pure air.
- As I constantly mention, the dose makes the poison. And these doses of environmental and vaccine aluminum are far below the minimum risk level for the body burden of aluminum.
- Only if you assume that the body cannot clear aluminum (usually only in the case of kidney failure), the cumulative dose of the metal doesn’t actually matter.
- There is a trope, pushed by the anti-vaccine world, that somehow injecting aluminum is much different than consuming or inhaling it. This is simply not based on any science known to the biomedical world. The kidneys filter out most of the aluminum salts way before it accumulates. Furthermore, inhaled and ingested aluminum occurs every single day unless your baby doesn’t eat or breathe, whereas the tiny dose of injected aluminum occurs infrequently.
There simply is no robust, peer-reviewed evidence that the amount of aluminum salts in vaccines are in any way harmful. But that never stops the anti-vaccine religion from making unfounded claims.
ASIA, not the continent
Asin et al. start out their paper by stating that autoimmune syndrome induced by adjuvants (ASIA) is an adverse reaction of vaccines. ASIA is a belief, pushed by Israeli immunologist Yehuda Shoenfeld, that certain autoimmune conditions are caused by aluminum adjuvants in vaccines.
However, ASIA has been thoroughly dismissed by most scientists and regulatory agencies. Numerous large case-control and cohort studies, both near the top of the hierarchy of biomedical research, have found no evidence of a relationship between vaccines, especially the HPV vaccine, and ASIA. For example, researchers looked at nearly 300,000 vaccinated and unvaccinated women (reviewed here) and found no link to ASIA. There are many more studies that show a similar lack of causal links.
Thus, before we even start critiquing this paper, the authors start with a bogus hypothesis that is unsupported by real scientific investigations. Unless, of course, you subscribe to anti-vaccine lies, memes, and tropes. Then you probably are a true believer.
Sheep vaccine study critique
Despite the fact that the paper has a couple of discredited claims, about aluminum and ASIA, there are other significant issues with the paper. Let’s review:
- The researchers only looked at a total of 21 sheep in 3 groups. Important clinical and epidemiological studies have thousands or even millions of data points. It is difficult, if not impossible, to determine a causal link with such a tiny sample size.
- The animals in the two experimental groups, one vaccinated with the typical vaccines given to sheep and the other with just aluminum adjuvant. The animals received 16 vaccine doses within 12 months for a total of 70.861 mg of aluminum. These are the number of doses that a sheep receive over 6-7 years! Furthermore, if you’re prone to comparing sheep to humans, that’s 20X more aluminum adjuvant than a human receives over a year – of course, human infants are smaller. Nevertheless, even though I dismiss any link between injected aluminum and neurological issues, giving 6-7 years of vaccines over 12 months biases the results. In addition, I’m skeptical of the behavioral observations, but it is possible that the serum aluminum levels are so high that it exceeds the safe limit for aluminum.
- The study was not randomized or blinded (or they failed to mention it in the methods section). You might think that randomization on matters with humans, but the researchers could have biased the results by the way they treated the sheep.
- This study relied upon subjective observations of the sheep’s “behavior” post-vaccination. These are the type of issues that hinder many behavioral and neurological studies – a subjective analysis of change in behavior is almost impossible to quantify. And when there are just 21 animals, it’s almost impossible.
- Sheep are social animals and the process of vaccination itself, especially so many over a short period of time, may induce behavioral changes irrespective of any contents of the vaccine, although the control group did receive a placebo injection.
- This sheep vaccine study is a primary research article – that means it lacks any supporting data anywhere else. It’s like the old vaccines cause autism canard – one retracted study supported it. On the other hand, literally hundreds of clinical and epidemiological studies along with meta-reviews have debunked that claimed link. That’s why most real biomedical researchers ignore primary animal studies – they pique interest, but rarely form the foundations of science-based medicine. Since we have dozens of studies that show no behavioral changes post vaccination, how much does a very small, very poorly designed sheep study tell us? Next to nothing.
- In a 2013 study by the same research group, they observed that around 0.5-1.0 % of animals of a flock exhibit the type of behavioral symptoms, irrespective of vaccination, described in the newer paper – yet they conveniently ignore it. Given the tiny sample size, the lack of randomization or blinding, and other issues, it’s impossible to tell if this is background noise.
I’m done here
The anti-vaccine religion has pounced on this study, which doesn’t surprise me or any other pro-science person out there. Dr. Bob Sears (the California pediatrician on probation for some issues about vaccine exemptions) and the crackpot science denier Robert F Kennedy Jr have tried to abuse this pathetic study to further their pro-disease for children beliefs.
This sheep vaccine study barely rises to the level of bad evidence – it provides us with nothing useful about the discussion regarding aluminum in vaccines. Moreover, there is overwhelming evidence, as shown in so many powerful peer-reviewed studies, that there simply is no link between aluminum adjuvants and anything.
Why do the anti-vaccine use this terrible sheep vaccine study to support their claims? Because they’ve got nothing else. Nada. Squat. Zilch.
- Asín J, Pascual-Alonso M, Pinczowski P, Gimeno M, Pérez M, Muniesa A, de Pablo L, de Blas I, Lacasta D, Fernández A, de Andrés D, María G, Reina R, Luján L. Cognition and behavior in sheep repetitively inoculated with aluminum adjuvant-containing vaccines or aluminum adjuvant only. Pharmacol Res. 2018 Nov 2. pii: S1043-6618(18)31373-2. doi: 10.1016/j.phrs.2018.10.019. [Epub ahead of print] PubMed PMID: 30395948.
- Liu EY, Smith LM, Ellis AK, Whitaker H, Law B, Kwong JC, Farrington P, Lévesque LE. Quadrivalent human papillomavirus vaccination in girls and the risk of autoimmune disorders: the Ontario Grade 8 HPV Vaccine Cohort Study. CMAJ. 2018 May 28;190(21):E648-E655. doi: 10.1503/cmaj.170871. PubMed PMID: 29807937; PubMed Central PMCID: PMC5973886.
- Luján L, Pérez M, Salazar E, Álvarez N, Gimeno M, Pinczowski P, Irusta S, Santamaría J, Insausti N, Cortés Y, Figueras L, Cuartielles I, Vila M, Fantova E, Chapullé JL. Autoimmune/autoinflammatory syndrome induced by adjuvants (ASIA syndrome) in commercial sheep. Immunol Res. 2013 Jul;56(2-3):317-24. doi: 10.1007/s12026-013-8404-0. PubMed PMID: 23579772.
- Perricone C, Colafrancesco S, Mazor RD, Soriano A, Agmon-Levin N, Shoenfeld Y. Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) 2013: Unveiling the pathogenic, clinical and diagnostic aspects. J Autoimmun. 2013 Dec;47:1-16. doi: 10.1016/j.jaut.2013.10.004. Epub 2013 Nov 13. Review. PubMed PMID: 24238833.