Scientific skepticism about vaccine safety: you’re doing it wrong


I don’t know what it is about vaccination that attracts so much vitriol, but in light of the recent pertussis outbreak which has claimed the life of an Albertan infant, I am loath to let anti-vaccine apologetics stand unchallenged. Today’s offering at the altar of McCarthy comes via Canadian pharmaceutical policy researcher, Alan Cassels.

Time to outlaw vaccine propaganda: Are we taking the easy way out by labeling vaccine questioners anti-science loonies?

… One survey of American parents a few years ago found that the majority of parents agreed that vaccines protect their children from disease but more than 50% expressed concerns regarding serious adverse effects. The same survey found more than 10% of parents had refused at least 1 recommended vaccine. What is at the heart of these concerns? Can it really be due to vaccine fear-mongering?

I don’t think it is.

Founding this entire column on the argument from personal incredulity is not a good start.

Parents just want to keep potentially harmful things away from their children. And they turn to health experts for guidance, but here’s my take on things: health authorities often fail to acknowledge the risks of some vaccines,

Which “health authorities”? The CDC, Health Canada, and every provincial website I visited explicitly acknowledged the side effects of vaccines.

 refuse to discuss uncertainty over a vaccine’s effectiveness,

This information is also clearly on those websites, but is also discussed in the blogosphere at length, since this is an important discussion to have.

hype the seriousness of common everyday viruses (c’mon folks, really? The flu? Chicken pox?)

I’ll be sure to let the 4000+ Canadians per year who die of influenza know that their preventable deaths are just hype.

and keep piling more and more vaccines onto the list of ‘recommended’ childhood shots threatening to turn our kids into pincushions.

This is a talking point straight out of the staunchest anti-vax campaigns, and has zero scientific basis. Would he be fine with giving childhood vaccines as currently recommended if they were all given via nasal mist? And wasn’t he just attacking public health for “hype”? Although I appreciate the emotional impact of a good metaphor, the author is attempting to make the point that he is not “anti-science.” Counteracting knowledge with emotional appeals does him no favours.

You’d certainly want to shelter your child from whooping cough if you could, but the advice around the vaccine is conflicting. Some groups, such as the CDC recommend vaccination of pregnant women and infants yet the vaccine leaflets themselves say it is unknown whether the vaccines cause fetal harm.

Pharmaceutical industry generally works under the assumption that everything causes fetal harm until conclusively demonstrated otherwise (for obvious liability issues). The CDC released a report last month from their adverse vaccine reactions data had only 22 incidents of spontaneous abortion after receiving DTaP, and one fetal malformation over the course of 5 years. Although we can’t conclude from this data that DTaP didn’t cause them, it seems that it would be exceedingly rare even if it does. You cannot equate these data with complete ignorance.

Some say the vaccine is highly effective, while others point to studies showing even fully vaccinated children still get whooping cough.

Who are these others and what studies do they point to? It’s well known that vaccines do not protect 100%, and that, particularly when herd immunity levels are low, it is still possible to become sick despite vaccination.

No one seems to know how many booster shots you need to keep your child protected.

Bonus points for creationism-style extrapolation of some scientific controversy on minor points to complete ignorance on the subject. The schedule for childhood pertussis (given in tandem with diphtheria and tetanus, as well as at varying time points: hepatitis B, polio,and Haemophilus influenzae type b) is not under debate. However, the effectiveness of the booster received as a teenager is. Of course, the question is not whether it is ineffective, but rather, if it is actually more effective than previously thought. Individual variability in immunity maintenance exists, so the question does remain about when older teens and young adults should get their boosters. In an ideal world, we would measure antibody levels in everyone so that we could vaccinate only those whose immunity is waning. From a public health perspective, until this can be done quickly, easily, and inexpensively, the debate will probably continue. This minor quibble does not mean that we are unsure if infants and toddlers receiving their routine childhood vaccinations are protected or not.

It’s also worth noting that there are multiple different types of booster shots, so depending on the preferred shot in your area you might be on a slightly different schedule. These differences have as much to do with “not knowing” about booster schedules as being unsure about whether insulin is effective because different types of insulin require different dosing.

Swirling masses of conflicting information reveal to me something very genuine: parents raising legitimate concerns over vaccine safety and effectiveness.

Parents do have legitimate concerns. I don’t think anyone is implying that their concern is illegitimate. If they are hearing through anti-vaccine movements that vaccinations are made with aborted fetuses and that their child will get autism, then that is a perfectly reasonable thing to be concerned about. If a scare mongering blogger writes a terrible article implying that we really don’t know how well vaccines work, parents have every right to ask questions.

One incontrovertible fact is that even if diseases such as whooping cough can, on rare occasions, lead to death, and some children can be injured, sometimes fatally, from vaccines. Thankfully these injuries are also rare, but cases of neurological dysfunction and permanent brain injury linked to vaccines do happen.

Deaths can happen from whooping cough. Death can happen due to vaccination. However, mentioning these two things in the same sentence does not make them equally probable.

In the last two years in the US, there have been nearly 2,500 awards for vaccine injury and death made under the US 1986 National Childhood Vaccine Injury Act.

This is patently not true. Checking the source data, there have been just over 3,000 compensations since October 1, 1988.

 More than half those awards involve the whooping cough vaccine.

Although a large portion of claims come from the various iterations of the diphtheria, tetanus and pertussis combination vaccinations, a child will receive 6 of these before adulthood, unlike other vaccinations which will be received 2-3 times. If we work under the assumption that every vaccination is an independent chance of vaccine injury, then obviously a vaccine that is given twice as much will result in higher frequency. Though this is not definitive proof, these data certainly suggest that DTaP is as safe as other vaccinations.

At the end of the day, most parents just want to know the answer to one simple equation: what is the likelihood that a vaccine will prevent a deadly disease, versus what are the chances of a serious adverse reaction to the vaccine? Shouldn’t this be a simple question to answer? But it isn’t.

But it is, because it has already been answered in the numerous sources I have already linked to. We can accurately measure the efficacy of vaccines using hard science. We have data about side effects. We know that when we drop overall vaccination rates, these forgotten diseases come back.

If public health authorities want to improve vaccination rates, they’d drop the patronizing assurances and start providing the public with some hard evidence of the benefits and harms of immunizing or not immunizing.

Vaccine policy does not do nuance well. Lacking quality information the public will continue to be buffeted by pro-vaccine hectoring or frantically anti-vaccine fear mongering. And the health of the public could use a whole lot less of both of these.


Quality information is everywhere. When I went in for my own pertussis booster recently, I was asked if I wanted more information on the HealthLink telephone service where I booked the appointment. I was given a pamphlet when I walked in for the appointment. The public health nurse who gave me the shot specifically asked me if I had any questions before and after the shot. I could have looked up information on the NCBI, CDC, Health Canada, or provincial government websites. I could have called my family doctor. I could have talked to any one of the numerous government resources specifically designed to assist parents address the health of their children. The information is right there. It is ridiculous to blame public health for a lack of information and simultaneously accuse them of “hectoring” the public.

Parents, we all care about our kids. We don’t deserve to be mislead by “frantic anti-vaccine fear mongering”. Inform yourself using your provincial health resources. Talk to your public health nurse, family doctor, or pediatrician. Call the health information hotlines. Think of Harper, and Dana, and the unnamed child from North Carolina, and realize how we, as a community, are responsible for the protection of our most vulnerable citizens.

Get informed, think about the incredibly tiny risks compared to the benefits, and then make the appointment to vaccinate your children. Saving lives doesn’t have to be glamourous.



Image credit to Hygiene Matters

11 Responses to “Scientific skepticism about vaccine safety: you’re doing it wrong”

  1. George Klima says:

    The illogical style of arguments used by the anti-vaccine crowd shares a great deal with the climate-change deniers.

    As Michael Mann says, “Widespread, bad-faith assaults on science have no place in a functioning democracy.”

  2. Chris says:

    What are Alan Cassels’ credentials? All I can see is he is a “researcher affiliated with the University of Victoria.” If I look at a biography there is no information on his education. I ask because if he claims to be an expert in pharmaceutical policies, he should not be making so many simple mistakes. Especially for something that is easily looked up like the awards given over more than twenty years for vaccine injuries in the USA.

    • As far as I can tell, the University of Victoria lists him as an “Associated Professional” and “Health Policy Journalist.” He has no scientific credentials – not ones he’s forthcoming about anyway. He’s got a publication in the CMAJ from about 10 years ago, and several fluff editorials published in journals as well.

      • Chris says:

        Thank you. Fortunately an alumnus of UVic provided an answer: He is listed as an “associated professional” in the Faculty of Human and Social Development. His degrees are a CD which appears to be an undergraduate degree in Community Development and an MPA which is a Masters in Public Administration. In other words, he is not “Dr” Cassels and he has no apparent education in science or medicine.

        I wonder if he is a friend of Chris Shaw at UBC.

  3. Unfortunately, the Internet is “flat” in the sense that it’s not obvious to many how valid the information on a given site is. In the supermarket checkout line, we treat the headline, “SCIENTISTS CURE CANCER” if it was on the front page of the Globe and Mail vs. the National Enquirer.

    This applies to books as well. After a long, frustrating, and ultimately unproductive debate about the merit of national immunization schedules, a friend sent me the Vaccine Safety Manual. It is full of misleading statements, invalid arguments, and anti-vaccine propaganda. I am not a scientist, but you might find my review of the book interesting:

    • Chris says:

      That is an awesome review. You will be amused by the “corrigendum” Mr. Miller needed to include in a recent paper. I see that one comment one your article references a couple of analyses of that paper.

  4. Gem Newman says:

    Is there a link available to the original article? Where did it appear? (Perhaps I missed it in the body of this post? If so, my apologies.)

  5. Ian Campbell says:

    Recently on CBC radio 1 medicine show (White Coat, Black Art, Dr Brian Goldman Friday 21 September) “Your body, your choice? Complementary alternative medicine show”
    Dr. Brian seems to endorse the use of naturopathy if only to reduce some of the pressure on the traditional health care system.
    The Alberta at Noon CBC radio show had a talking point on the current Alberta Health Care Influenza Vaccination program. The next day October 25, the program aired a letter from a listener/mother who didn’t want to vaccinate her child because of the dangers and who said that the nurse (at the vaccination distribution centre) reportedly would not use vaccines on her own children either.


  1. [...] two bloggers have beaten me to it. Over at Skeptic North, Richelle McCullough has done a thorough line-by-line rebuttal to the entire post. And Orac at Respectful Insolence has also weighed in, with Antivaccine fear mongering? What [...]

  • Richelle McCullough

    Richelle is a second-year medical student living in Calgary, but hails originally from Winnipeg. An outspoken advocate for lifestyle interventions within the scope of science-based medicine, Richelle’s favourite topic is to debunk complementary and alternative medicine. She is frequently trolled by geocentrists at her personal blog, Subspecies, and despite the distance, remains active with the Winnipeg Skeptics.