One of the enduring zombie myths pushed by the anti-vaccine side is that their children are healthier than vaccinated children. But are vaccinated children sicker? Not based on any real, scientific evidence. But that never stops the science denying anti-vaccine crowd.
The vaccine myth website, vaccines.news, published an article recently pointed to two poorly designed studies to make the outlandish claim that vaccinated kids are sicker. One the studies, a German one, which used internet surveys (yeah, think about that) to get data, was pushed by several anti-vaccine groups, including the propaganda blog, Age of Autism, as “proof” vaccines are dangerous. But as the silver-tongued Orac concluded:
In any case, I take some comfort in the hilarious result of this survey that demonstrates that autism prevalence in the unvaccinated is similar to autism prevalence among the vaccinated, no matter how much anti-vaccine activists try to spin it otherwise. I realize that this survey is in fact so poorly designed that it really doesn’t tell us much of anything, but it is fun watching anti-vaxer brains explode trying to spin this result as supporting the vaccine/autism hypothesis.
Remember, there is no scientific evidence supporting the vaccine/autism hypothesis.
Now we have a new study that barely rises to the same abhorrent quality level of the aforementioned German study. Of course, we have to look at it.
Vaccinated children sicker – the research behind the myth
The claims that are circulating across the anti-vaccine blogosphere are based on a recent article published in the Journal of Translational Science. Before we get into the article, you might be wondering what is “translational science,” because it sounds a bit woo-based. Translational medicine or science is an interdisciplinary approach which combines resources, expertise, and techniques within basic sciences to discover enhancements in prevention, diagnosis and therapies for various diseases. It’s actually pulling medicine back to basic sciences to better understand everything going on in the body.
For example, they may discover a mutated gene that produces a dysfunctional protein that has a profound effect on the body. They then target that gene and its protein production to treat the disease, rather than target the symptoms that are caused by the bad protein. Translational medicine is an exciting field of biomedical research, on which has shown much promise. However, some “translational medicine” has moved into the world of woo.
Here’s what the Journal of Translational Science (JTS) says its goals are:
JTS is a novel journal that will focus upon the translation of cellular, molecular, and genetic pathways into clinical strategies for multiple medical disciplines that can impact a broad spectrum of disorders that involve stem cells, degenerative diseases, aging, immune function, tumorigenesis, epigenetics, musculoskeletal function, cognition, behavior, neuronal, cardiac, pulmonary, gastrointestinal, and vascular targets, and metabolic function overseeing all aspects of translational research and medicine. JTS will provide a platform in today’s scientific and medical literature to serve as an international forum for the healthcare and scientific communities worldwide to translate novel “bench to bedside” science into clinical therapies as well as report upon prognostics, novel therapeutic strategies, and biomarker development.
That’s all well and good, but the study from JTS that we’re discussing in this post doesn’t fit in any of those. And a review of much of the research they publish is laughably woo-based. In the same issue of JTS as the article we’re discussing, they had published an article examining traditional Chinese medicine, which is neither traditional nor medicine.
So, let’s take a closer look at the “vaccinated children sicker” paper.
A 10,000 meter meta critique of the paper.
There’s a lot to dislike about this paper and journal. But I think it’s important to take a meta-approach to this paper to make sure you have a good grasp of the quality of what we’re critiquing.
- The Journal of Translational Science is not indexed in PubMed. It’s been over two years since the journal was first published, and it is rare for a journal to not be indexed there. Without PubMed, it is extraordinarily difficult to cites one of the articles published in JTS. Of course, there’s no reason given for it’s exclusion from PubMed, but we can speculate that possibly the science is bad.
- JTS lacks an impact factor. The impact factor gives us a relative understanding of the quality of a journal – generally, the impact factor tells us approximately how many times an average article published in a journal is cited per year. A journal like Nature has an impact factor of 36, which means the average article is cited 36 times a year. Why is this important? We know that more pivotal and valuable research is cited many times and often repeated by other scientists, especially in new publications. This is how science develops solid evidence, by examining and repeating the findings of others.
- The publisher of JTS, OAT, is a predatory publisher according to the definitive Beall’s List of predatory publishers. A predatory publisher is “exploitative open-access publishing business model that involves charging publication fees to authors without providing the editorial and publishing services associated with legitimate journals.”
- Low impact factor, predatory journals are generally dismissed by scientific researchers because the peer-review is weak. These journals are often abused by researchers whose data has been rejected by one or more of the respected journals, so they settle for these low quality versions. In the academic community, publications such as these often cannot be used as evidence of qualification for tenure.
None of these issues alone should lead one to dismiss the data outright. However, if one had real data that leads to a conclusion that “vaccinated kids sicker – watch out,” it would have been accepted by any of the journals that have focus on vaccines. But if the research was not well-designed, and well-analyzed, then the better journals would move away, and quickly, from adding it to their publication.
Critique of the “vaccinated children sicker” paper
The authors, Anthony R Mawson et al., hypothesized that there was an association between vaccines and neurodevelopmental disorders (NDD) of 6- to 12-year old biological children. The study was of home schooled children in Florida, Louisiana, Mississippi and Oregon. The mothers were asked to complete an anonymous online questionnaire on their children with respect to pregnancy-related factors, birth history, vaccinations, physician-diagnosed illnesses, medications used, and health services utilized. The NDD was defined as having one or more of these diagnoses – learning disability, attention deficient hyperactivity disorder (ADHD), and autism spectrum disorder (ASD).
The study found the following conditions were more prevalent in vaccination children:
- Allergic rhinitis (odds ratio = 30.1). We’re going to take a look at odds ratio down below.
- Other allergies (OR= 3.9)
- Eczema/atopic dermatitis (OR=2.9)
- Learning disability (OR=5.2)
- ADHD (OR=4.2)
- ASD (OR=4.2)
- Any chronic illness (OR=2.4)
Well, all that sounds like vaccines are worse for our children. Except it really doesn’t.
How about we jump in with a harsh critique of these kinds of studies:
- It uses an internet questionnaire to determine each of the data points for this study. The use of questionnaires for epidemiological studies is frowned upon by many researchers. The reasons for this are many, but they include a reliance upon the memory of the participant for events that may be not be recalled correctly. In addition, there might be intentional or unintentional bias of the survey participants towards relating a condition to vaccines or ignoring one in unvaccinated kids. Better done, and frankly, more expensive, epidemiological studies rely upon medical records to reduce errors in memory and bias. This is a critical point – the best studies that show no link between vaccines and autism rely upon actual medical data for each child, not on a questionnaire which may or may not be tracking accurate information.
- Home schooled groups are unrepresentative of the school age children at large. Many children are homeschooled because of parents dislike of vaccinations, so this forms a biased group. Now, maybe the home schooled group mirrors a traditionally schooled group – if you want to make that case, then you need actual data published in an actual journal.
- Parents who do vaccinate may be less reluctant to visit their physician to get diagnosed for diseases, while a non vaccinating parent may choose to ignore any health issues as minor. Thus, there may be an unintentional bias towards health care issues for vaccinated children.
- The groups (vaccinated vs. unvaccinated) are not randomized which will lead to observational and confirmation bias.
- The population for the study is quite small to tease out data on very rare conditions. A meta-review that included nearly 1.3 million children, using real medical records to establish both vaccination status and ASD status, found that there was no difference between vaccinated and unvaccinated groups with respect to incidence of autism.
- There was a lack of analysis of potential cofounders which might bias the results. Were there other differences between he vaccinated and non-vaccinated groups that could have biased the results one way or another?
- The use of odds ratio by the researchers is curious and may have biased the results. The only reason to use OR is to inflate the difference between both groups. Real epidemiologists prefer relative risk (RR) which provides us with a much more sensitive understanding of the incidence of a condition in a vaccinated group vs. an unvaccinated group. For example, the RR for ASD from this study (if the data actually were useful, which it isn’t) is 3.1, whereas the OR is 4.2.
- The over reliance on p-values is always a red flag to researchers. With so many p-values, the probability of false positives is fairly large. Because the population for the study was so small, it’s also worth nothing that the OR had relatively large error brackets, most of which crossed near unity, that is, 1.0, indicating no difference between the groups.
- The authors seem to overlook or ignore the point that the vaccinated children had much lower risk of diseases like chickenpox and measles, which we know bring with them significant risks of long-term health issues. Even if we accept this poorly designed study as providing us with evidence of harm from vaccines, one would have to balance it against the benefits of avoiding vaccine preventable diseases. Of course, this study is so bad, it’s hard to accept anything useful from it.
Predictably, the authors conclude that:
First, additional research is needed to replicate the findings in studies with larger samples and stronger research designs. Second, subject to replication, potentially detrimental factors associated with the vaccination schedule should be identified and addressed and underlying mechanisms better understood.
Maybe because their paper was published in a journal that is not indexed in PubMed, they didn’t search there. If they had, they would have found find 100s of articles, with much better, unbiased studies that conclude that there is no link between vaccines and neurodevelopmental disorders. I’ll simplify for Mawson et al., I reviewed and wrote an article that include the most important real science articles that they are wrong about vaccines and neurodevelopmental disorders.
Are vaccinated children sicker? Well, if you listen to the anti-vaccine crowd, who have cherry picked Mawson et al. to support their pre-conceived faith that vaccines and autism are linked, you’ll buy into the anti-vaccine conclusions:
This pilot study shows us that if mainstream medicine and our public health agencies are really interested in children’s health, not just vaccine profits or defending vaccine religion against blasphemy, what is needed is not the will to make everyone believe, but the courage to find out.
But real science says that the study used by this anti-vaccination believer is poorly designed, and it does not show what they claim it shows. It’s biased, poorly analyzed, and comes to conclusions that are not supported by the vast mountains of real science published in real (read, non predatory journals). No real scientist would accept the findings of this paper, other than to laugh heartily. I don’t laugh, because I know some crackpot will use it to “prove” that vaccines are dangerous, when there’s no robust evidence to support that belief.
Vaccines are safe. Vaccines are effective. A badly designed, irresponsibly published article does not change the vast consensus of scientists that vaccines are safe and effective.
- Mawson AR, Ray BD, Bhuiyan AR, Jacob B (2017) Pilot comparative study on the health of vaccinated and unvaccinated 6- to 12-year-old U.S. children. J Transl Sci 3: DOI: 10.15761/JTS.1000186.
- Taylor LE, Swerdfeger AL, Eslick GD. Vaccines are not associated with autism: An evidence-based meta-analysis of case-control and cohort studies. Vaccine. 2014 Jun 17;32(29):3623-9. doi: 10.1016/j.vaccine.2014.04.085. Epub 2014 May 9. PubMed PMID: 24814559.