More Non-Vax Nonsense

This post is the continuation of last week’s rebuttal of a recent article published on by Jennifer Margulis, entitled “Pregnancy and the Flu Shot.”

Margulis’ article continues with another anecdote (calling to mind a quote I love, often attributed to Roger Brinner, which states: “The plural of anecdote is not data”). This time, the story is about a woman who got the flu shot, and then proceeded to get influenza. No medical intervention or treatment — not ONE — is 100% effective. This is true of all diagnostic techniques, all medications, all vaccinations, all surgeries. In the case of the influenza vaccination, there’s the additional complication that the CDC must make an educated forecast (which Margulis refers to as a “guess,” as though it’s made by throwing dice rather than based upon sound scientific techniques) as to which strains of flu are likely to be most prevalent in a given year. The simple fact is that the CDC doesn’t — can’t — always forecast accurately, but most times they do. Even those years in which the flu shot doesn’t prevent the flu, it attenuates the severity. In the end, deciding to get the flu shot (like so many other decisions) involves doing a risk-to-benefit analysis. The question is, quite simply, do the benefits of getting the shot outweigh the risks.

In order to do a proper risk-to-benefit analysis, it’s important to know both the risks and the benefits. Strong scientific evidence supports that the flu shot is effective in pregnant women (see, for instance, Sumaya et al, Murray et al, Zaman et al). The Sumaya and Zaman studies further examined the efficacy of a maternal influenza vaccination in preventing influenza in newborns. The studies found that, up until about 6 months of age, the infants had influenza antibodies (indicating some degree of immunity, Sumaya et al) and reduced incidence of flu (Zaman et al). One complication in determining the effectiveness of the flu shot is that the vaccine doesn’t prevent non-influenza respiratory illness, and the only way to be sure that a case of illness is influenza is to test for it. As a result, some studies (for instance, Black et al) measure the impact of the influenza vaccine by looking at the rate of medical visits and/or hospitalizations for ANY respiratory illness in vaccinated versus unvaccinated individuals. Studies that don’t measure the effectiveness of the flu vaccine by looking at actual reduction in flu are less likely to show that the vaccine is effective, but to the credit of the researchers, many — including Black and colleagues — admit this shortcoming and weakness of the research. In the end, organizations and researchers who review the scientific literature feel that the shot is effective (that is to say, confers a definite benefit) in pregnant women (see, for instance, Tamma et al, Mak et al, and the recommendations of the CDC).

Then there is the matter of analyzing the risks associated with the influenza vaccine. A large number of scientific studies have shown that routine influenza vaccination is not associated with any severe side effects in individuals who are not allergic to its ingredients (egg, for instance). Pregnant women are not at any greater risk of side effects than non-pregnant individuals, and research suggests no increased risk of pregnancy-related complications (see, for instance, Tamma et al, Munoz et al, Mak et al).

One point in particular made by Margulis is that thimerosal, a mercury-containing preservative in flu vaccinations, causes harm (because mercury is a potent neurotoxin). However, no studies have found any evidence of harm from thimerosal exposure in flu vaccines (see, for instance, Tamma et al). Moreover, a study that looked specifically at neurodevelopment (researchers have wondered if thimerosal could be responsible for increasing the risk of autism and ADHD in infants) found no increased risk of these disorders in thimerosal-exposed infants (Verstraeten et al). Margulis makes the point that the thimerosal studies are weak because they do not include a control group. However, here, she demonstrates her ignorance of the scientific method and of study design. Human experimentation, particularly when it comes to determining whether a substance is dangerous to infants, isn’t ethical. Thimerosal studies aren’t done by injecting some babies (or pregnant women) with thimerosal-containing vaccine and others (the control group that Margulis is looking for) with a vaccine that doesn’t contain the thimerosal. Instead, studies are done by retrospectively (afterward) comparing the health of infants who were exposed to thimerosal to that which is considered normal or expected (“normal” is the control group, even though there isn’t an explicit control in the experimental design). This sort of design is common in medicine and allows ethical determination of toxicity; there is no flaw here.

In the end, while there is good reason to continue to study the effects of thimerosal in vaccines, evidence suggests that in small and occasional doses, it’s not likely to be a problem. Wait, LIKELY? You mean I’m taking a RISK? Yes, you are. You take a risk every time you eat food (it could contain pesticides, mercury, Listeria…), breathe outdoor air in the city (you are breathing pollutants, including benzene and formaldehyde, that cause illness and cancer), enjoy the sunshine (it’s breaking your DNA and possibly causing cancer), or take a tablet of over-the-counter medication (you could be allergic, or could have an adverse reaction). Life is all about risks. There is nothing you do that is without risk. The idea is not to avoid all risk — because that would be impossible — it’s to take MEASURED and APPROPRIATE risks that are WORTH THE BENEFITS. I doubt anyone would argue (at least, not successfully) that you shouldn’t eat, breathe, walk in the sun, or take over-the-counter medication because of the risk. The benefits in each of those cases (and in the case of influenza vaccination) outweigh the risks.

The problem here, as in so much of the anti-vax rhetoric and other harmful nonsense propagated on the Internet and elsewhere in the media, is that Margulis simply isn’t qualified to make judgments on scientific issues. She’s a journalist, according to her byline, and is without a scientific background (possible intro courses in college notwithstanding). As Alice at Science of Mom so beautifully put it in this wonderful guest-post at The Mother Geek, “It would be naïve for me to think that I could understand the vaccine field better than the committees of scientists and doctors who have made this their life’s work.” And that’s coming from a PhD in science! Heck, I’m on that same page; there’s no WAY I would have the hubris to think that I could know better than vaccine scientists whether a vaccine is a good idea, is safe, or confers benefits. That’s why I leave making those decisions to the vaccine scientists. My question, then, is this: if PhDs in science feel it’s important to turn to the TRUE EXPERTS to make vaccination decisions, why doesn’t a journalist? Why don’t the celebrities? Why don’t the moms with great instincts, but no scientific background, who do their vaccination “research” on sketchy Internet sites and by listening to Jenny “Formerly Host of Singled Out” McCarthy instead of by turning to medical experts who’ve made investigating vaccines their life’s work?


Science Bottom Line:* The influenza vaccine is safe and effective in all trimesters of pregnancy, and research supports getting it.


Do you trust the experts? Why or why not?



Black et al. Effectiveness of influenza vaccine during pregnancy in preventing hospitalizations and outpatient visits for respiratory illness in pregnant women and their infants. Am J Perinatol. 2004 Aug;21(6):333-9.

CDC. Prevention and Control of Influenza, Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Morb Mortal Wkly Rep. 2011 Aug 26;60(33):1128-32.

Mak et al. Influenza vaccination in pregnancy: current evidence and selected national policies. Lancet Infect Dis. 2008 Jan;8(1):44-52.

Munoz et al. Safety of influenza vaccination during pregnancy. Am J Obstet Gynecol. 2005 Apr;192(4):1098-106.

Murray et al. Antibody response to monovalent A/New Jersey/8/76 influenza vaccine in pregnant women. J Clin Microbiol. 1979 Aug;10(2):184-7.

Sumaya et al. Immunization of pregnant women with influenza A/New Jersey/76 virus vaccine: reactogenicity and immunogenicity in mother and infant. J Infect Dis. 1979 Aug;140(2):141-6.

Tamma et al. Safety of influenza vaccination during pregnancy. Am J Obstet Gynecol. 2009 Dec;201(6):547-52. Epub 2009 Oct 21.

Verstraeten et al. Safety of thimerosal-containing vaccines: a two-phased study of computerized health maintenance organization databases. Pediatrics. 2003 Nov;112(5):1039-48.

Zaman et al. Effectiveness of Maternal Influenza Immunization in Mothers and Infants. N Engl J Med. 2008 Oct 9;359(15):1555-64. Epub 2008 Sep 17.


7 Comments (+add yours?)

  1. Trackback: Non-Vax Nonsense |
  2. krista
    Jan 10, 2012 @ 04:57:24

    And what if the individual IS allergic to the ingredients? (Egg)


    • SquintMom
      Jan 10, 2012 @ 16:00:08

      Well, in many cases, the vaccine can safely be given to people who are allergic to egg. If a person has had a reaction to egg in the past (or has tested positive for egg allergy), it’s important to talk to a physician before getting a flu shot. The doctor will most likely recommend going ahead and getting the shot (because there is a significant crossover between those who are allergic to eggs and those who are at greatest risk of complications from the flu), but may have you wait around for about half an hour afterward in case of a reaction. In the majority of cases, an egg-allergic individual will not react to the very small amount of egg in the shot.


  3. Alice Callahan
    Jan 11, 2012 @ 19:57:51

    Great article once again, and thanks for including a link to my article! I used to shy away from the vaccine debate, but I really am starting to feel like I have a responsibility to disseminate accurate information to counter all of the misinformation. I am disappointed in Mothering magazine on this one and glad you responded. I’d like to spend more time writing about cool new science, but it is hard to ignore blatant misinformation such as this in the popular press. Thanks again and keep up the awesome work!


  4. Lorie
    Jan 12, 2012 @ 10:09:55

    I had the same reaction after reading her article and then reading credible information on the topic. I also had read her Vaccine Debate article in Mothering and was struck by her cherry-picking of studies and use of anecdotes to support her position, which she says is not anti-vaccine but “selective-vaccination” – coulda’ fooled me.
    It does surprise me that Black et al didn’t at least find some reduction in overall respiratory hospitalizations or deaths among the vaccinated in such a large study, even if not looking at just verified flu cases. I do wish they had elaborated more on the weaknesses of their study to explain this unexpected result (but I only have access to the abstract, so maybe they did).
    Many experts see a need for more effective flu vaccine(s) to be developed (Cochrane Reviews; and Osterholm MT, Kelley NS, Sommer A, et al.). Current flu vaccines can be remarkably ineffective when a poor match is made to the circulating viruses, or when it’s a mild season anyway – a situation that lends some “truthiness” to Margulis’s position. She exploits these limitations and then exaggerates and makes up dangers to make it appear that the risks outweigh the benefits.
    I thought it was particularly annoying that she apparently thinks avoiding death is the only reason to vaccinate. The story she told about the poor pregnant women “praying to the porcelain god”, suffering the worst experience of her life, sounded like a good enough reason to vaccinate.
    Anyway, thanks for the critique of her article!


  5. mary
    Jan 25, 2012 @ 04:00:26

    it says rite on the insert that safety and efficacy have NOT BEEN DETERMINED in pregnant persons…


    • SquintMom
      Jan 25, 2012 @ 05:23:45

      Right on the insert? I assume you mean on the paperwork you’re given to sign when you get a vaccination? Actually, there are several studies (they’re cited in this article and in its companion, “Non-Vax Nonsense”) that show flu vaccinations are both safe and effective in pregnant individuals.


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