The lowest form of evidence

When we are presented with a public health problem, we epidemiologists are always obligated to ask for the data. “The plural of anecdote is not data,” we say with glee. Although the saying is somewhat controversial with some people, I like to think that it is fairly accurate when it comes to public health (and medical) issues. For example, if my neighbors come to me to tell me that there is a cancer cluster in my town, I want to see the evidence because not all my neighbors are biostatisticians (or oncologists), and because I need to make sure that they’re arriving at that conclusion based on a reasonable set of observations. Many, many, many times, we are fooled by someone touting their credentials and making themselves out to be experts on something.

I woke up to this “opinion editorial” in my email inbox this morning courtesy of Google News. It was written by Stephanie Foist Mills, a chiropractor in Pembroke, NH. The opinion piece is critical of vaccine policy, something that I’ve come to hear far too much from chiropractors over the years. It’s almost as if they were taught in chiropractic school that vaccines are the source of all evil, contrary to all the evidence in the world that they’re not. Ms. Mills writes this:

“Rather than pass judgment, we should respect parents who have researched, soul-searched and even prayed to make the right decision. Too often parents are coerced, fooled or bullied into vaccinating our children by government experts, doctors and schools without proper explanation or discussion as to each vaccine’s safety or validity.”

Indeed, we should not pass judgment, when it is unreasonable to do so. When it’s reasonable, we must pass judgment, weigh the evidence, and say whether someone’s fears are unfounded or not. For example, the following is Ms. Mills’ statement on the Hepatitis B vaccine:

“Why is the Hepatitis B shot generally administered to babies in hospitals at only 12 hours old? This vaccine is for a blood-borne, sexually transmitted disease. Not only do most infants have little risk of contracting this disease, but the Centers for Disease Control’s own head epidemiologist stated that this vaccine has 10 times more serious reactions than other vaccines.”

Yes, hepatitis B is a blood-borne and sexually-transmitted disease, but it is also a disease that can be transmitted in other ways, ways that can have someone exposed without knowing it. The way that Ms. Mills writes this, I would be inclined to say that I’m not at risk of hepatitis B as long as I don’t use IV drugs, have safe sex, and don’t get exposed to other people’s blood. While all of those would reduce my risk, they will not eliminate it. For that small sliver of chance of getting hepatitis B, we have the safe and effective hepatitis B vaccine. But you don’t have to take my word for it being safe and effective, the evidence says so. That is, it is not my opinion that it is safe; it is a well-documented fact. However, Ms. Mills states otherwise:

“…but the Centers for Disease Control’s own head epidemiologist stated that this vaccine has 10 times more serious reactions than other vaccines.” (My emphasis added.)

What is she talking about? I didn’t find a citation to this statement anywhere in her op-ed, so I had to do some Google-fu and came up with nothing. Even the National Vaccine Information Center (an anti-vaccine organization that publishes “information” on vaccines) doesn’t have this statement in their hepatitis B vaccine page.

But let’s look at why we vaccinate newborns. According to the Advisory Committee on Immunization Practices:

“Rates of new infection and acute disease are highest among adults, but chronic infection is more likely to occur in persons infected as infants or young children. Before hepatitis B vaccination programs became routine in the United States, an estimated 30%–40% of chronic infections are believed to have resulted from perinatal or early childhood transmission, even though <10% of reported cases of hepatitis B occurred in children aged <10 years (1). Chronically infected persons are at increased lifetime risk for cirrhosis and hepatocellular carcinoma (HCC) and also serve as the main reservoir for continued HBV transmission…

Even with improvements in the management of pregnant women, only approximately 50% of expected births to HBsAg-positive women are identified (on the basis of application of racial/ethnic-specific HBsAg prevalence estimates to U.S. natality data) for case management, which maximizes timely delivery of postexposure immunoprophylaxis (11; CDC, unpublished data, 2004). The need for proper management of women without prenatal care, including HBsAg testing at the time of admission for delivery and administration of the first dose of vaccine to infants <12 hours of birth, is underscored by the higher prevalence of HBsAg seropositivity among these women than among women who are screened prenatally (12). Even when maternal HBsAg testing does occur, certain infants of HBsAg-positive mothers do not receive postexposure immunoprophylaxis because of testing errors and lapses in reporting of test results (13), and infants of women with unknown HBsAg status at the time of delivery often do not receive a birth dose of vaccine (14).”

In other words, we’re trying to vaccinate infants because they are more likely to get chronic hepatitis B for the rest of their life, resulting in many years of potential life lost, many liver transplants, and greater mortality. On top of that, we are only identifying half of births to mothers with hepatitis B. The other half are going undetected, so we need to make sure they’re protected immediately through vaccination. If Ms. Mills would read the why of this vaccine policy, maybe she would come to a different conclusion. Instead of just questioning why, it would be a benefit to her to also seek the answer (and not from NVIC).

Ms. Mills continued in her op-ed:

“Why do we now vaccinate for chicken pox? Contracting chicken pox was once a rite of passage among kids, conferring a lifetime of immunity. In 1983, only 23 doses of seven vaccines were given by age 6. Today kids are pin-cushions, with the CDC recommending 49 doses of 14 different vaccines by age 6. I’d say we’re being sold unnecessary vaccines for merely inconvenient diseases.”

This is a common trope among anti-vaccine people. They claim that childhood diseases like chickenpox are mere inconveniences. They’re not. In a developed country like the United States, a case of chickenpox may not kill you. (Likewise, there is no evidence that you gain lifetime immunity. More on that later.) But it will keep you out of school and your parents out of work to take care of you. Furthermore, at this time like no other in our history, more and more people are walking around in our society without a healthy immune system because of cancer, advanced HIV, diabetes, and old age. Unlike children, these folks can die from an “inconvenient” disease like chickenpox. And then there are those children who do die from chickenpox. In essence, chickenpox is not an inconvenience, and death is not the ultimate measure of disease severity.

The number of vaccines has increased because our medical technology has gotten better. We’ve discovered new vaccines (and vaccine technologies) and have implemented them. They were not implemented “willy-nilly” and without scrutiny. The manufacturers were not the only ones involved in the pre- and post-licensure studies. Members of the public serving on Institutional Review Boards were involved. Healthcare providers who administer the vaccines and receive zero compensation from anyone for it (except, of course, the patients paying the bill) were involved in these safety and efficacy studies. Academic researchers who want to find a better way to give vaccines were involved. Competing companies who want to find something wrong with their competitors’ vaccines were involved in it. Everyone was involved in it.

Ms. Mills continued:

“Can we trust the studies funded by the manufacturer who stands to profit? In the seven months following licensure of Gardasil, more than 600 vaccine reactions were reported, many involving serious neurological symptoms and death. According to the National Vaccine Information Center, the HPV vaccine was studied for less than three years and didn’t include a “true placebo” in its safety trials.”

This is another bit of misinformation about Gardasil (the anti-HPV) vaccine, and one that we can’t seem to get NVIC to stop spreading. Yes, that many reactions were reported, out of over 56 million doses given. Furthermore, the studies did include placebo groups. One-third of participants in study 018 of the Gardasil trials (comprising almost 2,000 participants) were given saline (salt water) instead of the vaccine. “True placebo” doesn’t get more “true” than that.

Now, if we are talking numbers, there are over 26,000 cases of HPV-caused cancer each year in the United States. Too many of those cases will end in death, something that has not been proven of the HPV vaccine.

Ms. Mills piles on:

“No one can guarantee any vaccine’s safety for your child. Decades ago Congress created a Vaccine Adverse Event Reporting System and special court to quietly deal with vaccine injuries and deaths. Since its 1980s inception, billions of dollars have been paid to compensate the families of vaccine-injured children.”

This is yet another anti-vaccine talking point. It seeks to convince you that the courts are the final arbitrator of scientific matters. They are not. When you compare the number of claims that have “won” in the special court versus the number that have not, the losses outnumber the wins. Furthermore, most of the “wins” come from a vaccine injury table that is agreed upon by all parties as something that will not assign fault but will compensate children having those conditions on the table after receiving the vaccines on the table. It’s a “no-fault” system designed to keep vaccines affordable. If anti-vaccine organizations had their way, they would have sued manufacturers and physicians into oblivion. (And you thought the price of healthcare was high now?)

And Ms. Mills concludes with this:

“I am not anti-vaccine; rather I am pro-health, pro-informed decision-making and pro-individual liberty. I am grateful to the health-care providers who take the time to discuss and create customized vaccine schedules. Here’s hoping that the New Hampshire Legislature gives us a conscientious objection option in the future. A great place to start educating yourself is at”

I have to be honest and tell you that I had to chuckle at this one. For someone who is not “anti-vaccine,” Ms. Mills has repeated many of the anti-vaccine talking points: Vaccines didn’t save us, too many vaccines too soon, natural immunity is lifelong and “better,” the adverse reports in the adverse reporting system are many and must be true, and childhood diseases are not that bad. Not only that but she points parents reading the op-ed to the NVIC, an organization that I (and others) call anti-vaccine because it acts anti-vaccine, states anti-vaccine talking points, and fights vaccination legislation left and right. If Ms. Mills is not anti-vaccine, then she comes damn near close to being and sounding like one.

The reason I titled this post “The Lowest Form of Evidence” is because opinion is the lowest form of evidence when it comes to epidemiology. It is followed by a case report, then a case series, then a survey, then a cross-sectional study, then a case-control study, then a cohort study, then a randomized clinical trial, then a meta analysis. From case-control on up, all studies keep coming up with nothing when it comes to the claims that vaccines are the source of lifelong, debilitating diseases. If anything, these studies keep showing that unvaccinated people are far more likely to end up as part of an outbreak of a vaccine-preventable disease. And they also show that vaccines prevent death and disability the world over, be it from polio, measles, or even the “inconvenient” chickenpox.

This op-ed piece by Ms. Mills, a chiropractor, should be taken as just that, an op-ed… Opinion, not fact. Had she bothered to cite the reasoning behind her opinions, it might have had more weight, but not much.

(I’m still scratching my head at her statement about the top epidemiologist at CDC. Please feel free to post it in the comments if you find it.)

Finally, the whole bit about chickenpox immunity. The reason why immunity from the disease was considered to be lifelong is because we kept being exposed to chickenpox. Each exposure after the initial infection would trigger a new immune response that would last some time, even years. As more and more children became immune via vaccination, we slowed down the rate of new infections and new outbreaks. More of us are not exposed anymore, and even those of us who had chickenpox as children will no longer be immune after a while. The chickenpox virus is an interesting one because, many times, it becomes dormant in our nerve tissues. Because of those continuing exposures and immune system activations, the virus did not get a chance to reactivate and give us the disease. As our immunity will wane (for reasons on top of just time), the virus may be reactivated and give us “shingles.” To prevent that, and because there aren’t that many snot-nosed kids walking around with chickenpox, there is a shingles vaccine. No, it would not be better to get the chickenpox as an adult.

And, yes, I realize that I did not call Ms. Mills “Doctor” Mills although she has a degree in chiropractic. Based on her opinions and level of understanding, it is my opinion that she has not earned my respect to call her “doctor,” a title I reserve to those who don’t parrot anti-vaccine (and anti-science) talking points.

[do action=”credit”]Photo credit: just.Luc / Foter / CC BY-NC-SA[/do]

I'm a doctoral candidate in the Doctor of Public Health program at the Johns Hopkins University Bloomberg School of Public Health. All opinions posted here are my own, of course, and they do not necessarily reflect the opinions of my school, employers, friends, family, etc. Feel free to follow me on Twitter: @EpiRen

2 thoughts on “The lowest form of evidence

  1. “Why do we now vaccinate for chicken pox? Contracting chicken pox was once a rite of passage among kids, conferring a lifetime of immunity. ”

    So was burying at least one, frequently two or three siblings, as well as a parent in a child’s youth. Should we bring that back as well?

    “The reason why immunity from the disease was considered to be lifelong is because we kept being exposed to chickenpox. Each exposure after the initial infection would trigger a new immune response that would last some time, even years.”

    Which also quite well explains the increase of people who suffer from shingles. Fading immunity due to aging and lack of re-exposure contribute to an increase in numbers of those whose varicella will reactivate and make them quite miserable.
    I know that for two reasons:
    1: There was no chickenpox vaccine when I was growing up. I was exposed and contracted chickenpox.
    2: Our children were part of the varicella vaccine test group. On contracted chickenpox many years later, the other did not. We suspect who got the placebo. Still, I ended up with a mild case of shingles. It was double plus unfun.

    “…and pro-individual liberty.”

    So, does she support my liberty to shoot her in the face with a bazooka as an expression of that individual liberty or not, hence she supports reasonable limitations on that liberty?
    No, I don’t own a bazooka. I’ll never own a bazooka. I have no use for a bazooka and would never shoot someone in the face unless they are trying to shoot me or a family member. In that latter case, it was how my team trained, zero reflex shots. I anticipate my contracting smallpox is a greater probability than someone threatening myself or my family, so I’ll leave my firearms in their safe. 🙂

    As you said, she hit many of the talking points, points that are zero points of accurate data.
    However, there are times when anecdote can contribute to epidemiology. Consider Sin Nombre hantavirus, one that was isolated in mice after researchers learned from Native American medicine men that hantavirus infections increased on El Nino years in one region.
    An examination on what happens in that region during El Nino years provided interesting information. For one thing, there were indeed increased cases. There was also increased rain in a rather dry area. More rain meant more grain being stored. Grain that attracted mice, who then ate as much of that excess grain as they could, whilst spreading Sin Nombre in their salive, feces and urine, to be atomized when the dried materiel was then agitated.
    Such as when handling said stored grain.
    One does not completely discard anecdote, but one regards it with a jaundiced view until some larger elements of the anecdote bear true.
    Something that has never happened with an antivaxer anecdote.


  2. Nah, she’s not anti-vaccine…she’s just plain ignorant and a poseur. She hasn’t got the reading comprehension about basic science that a smart adolescent has.

    There is a protocol set up for each County and each State Perinatal Hepatitis B Prevention Program coordinator, to address some of those issues where accurate maternal hepatitis B carrier status was not available (or was incorrectly noted in the pregnant woman’s chart), at birthing hospitals, to vastly decrease the chances that exposed newborns are not provided with HBIG and the first hepatitis B vaccine at birth. You might want to look at the the NY State PHBPP program manual. I *know* one of the nurses who set up those protocols.:


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