Accepted Manuscript

Review

The Clinician’s Guide to the Anti-Vaccinationists’ Galaxy

Gregory A. Poland, Robert M. Jacobson

PII: S0198-8859(12)00082-1

DOI: 10.1016/j.humimm.2012.03.014

Reference: HIM 8870

To appear in: Human Immunology

Received Date: 16 December 2011

Accepted Date: 19 March 2012

Please cite this article as: Poland, G.A., Jacobson, R.M., The Clinician’s Guide to the Anti-Vaccinationists’ Galaxy,

Human Immunology (2012), doi: 10.1016/j.humimm.2012.03.014

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The Clinician’s Guide to the Anti-Vaccinationists’ Galaxy

Gregory A. Poland (1,2,3,4) and Robert M. Jacobson (1,2,4)

1 Mayo Clinic Vaccine Research Group

2 Program in Translational Immunovirology and Biodefense

3Department of Medicine

4Department of Pediatric and Adolescent Medicine

Mayo Clinic, 611C Guggenheim Building, 200 First Street, SW Rochester, MN 55905,

USA.

Correspondence to G.A.P. e-mail: poland.gregory@mayo.edu

MeSH Keywords: Vaccines, Vaccination, Immunization, Immunology *Attitude to

Health. *Health Promotion / mt [Methods]. Humans. Influenza Vaccines. Measles-

Mumps-Rubella Vaccine / ae [Adverse Effects]. Measles-Mumps-Rubella Vaccine / hi

[History]. *Treatment Refusal. Vaccination / hi [History]. Vaccination / px [Psychology].

Abstract

In this paper we briefly review three common immunological misconceptions that feature

prominently among anti-vaccinationists, and in turn, fuel patient and parental concerns,

questions, and fears about vaccines. In particular, this Perspective covers a brief history

of the anti-vaccine movement, and three common false immunological claims, namely,

concerns over “antigenic overload”, the induction of autoimmunity by vaccines, and the

value of “natural immunity” versus vaccine-induced immunity. This is followed by a

review of the harms that have been done by anti-vaccinationists, and a call to action.

Regardless of the motivation behind such fears and anti-vaccine sentiment, common fears

and concerns relevant to vaccines are evident and therefore are the subject of this

Perspective. It is hoped that clinicians will find this information useful in answering

concerns and misconceptions about vaccines, and in educating their patients.

Preface

Vaccines have been a modern miracle of science that have saved many millions of lives,

eradicated one disease (smallpox), controlled many other infectious diseases, and

improved our quality of life. Vaccine-preventable diseases now occur in the developed

world at a fraction of the rate they occurred before the introduction of vaccines. Despite

this, the routine use of vaccines is threatened by a spectrum of fears, mis-information,

and anti-vaccinationist propaganda. In this article we discuss some of the most common

misconceptions about vaccines and provide information that clinicians might find useful

in countering anti-vaccine claims.

Despite the fact that the routine use of vaccines over the last century has led to a marked

decrease in the incidence of vaccine-preventable infectious diseases and epidemics,

widespread suspicion, mistrust and anti-vaccine sentiment are at surprisingly high levels

in the United States, Western Europe and even developing countries within Africa, India

and others. Although vaccines have frequently provoked fears and anti-vaccine

sentiment since their introduction (as discussed below), the resulting decrease in vaccine

uptake might have more severe consequences today than at any other time in the past.

The effects of vaccine refusal today are exacerbated by increased risks of exposure due to

the extent of global travel unprecedented in the history of humankind, the lack of immune

boosting from subclinical infection with wild viruses or bacteria that cause epidemic

diseases (such as measles, mumps, rubella and pertussis) owing to the success of

vaccination, and increases in the number of individuals with increased susceptibility to

these diseases (such as the elderly and immunocompromised persons), and situations in

which humans are crowded together (schools, training camps, sporting and musical

events, airplanes, indoor shopping malls, etc.). Together, these factors result in increased

risks for epidemics of vaccine-preventable infectious diseases, as shown by recent

outbreaks of measles, pertussis, and varicella, among other vaccine-preventable diseases,

in the United States, Europe, and elsewhere [1-8]. For example, recently, two individuals

with measles walked through the Superbowl Village in Indianapolis, and thus far 13

known cases of measles have resulted [9].

Why, despite decades of data demonstrating vaccine safety and efficacy, do anti-

vaccinationists and vaccine fears exist? We acknowledge that a spectrum of anti-vaccine

feelings exists from those fearful of real (but rare) or unsubstantiated vaccine side effects,

to those with differing or conflicting values, those who are un- or mis-informed, those for

whom innumeracy is an issue [10] (those who do not have an in-depth understanding of

probability or statistics), denialists [11] (those who simply refuse to believe the data),

those with low complexity cognitive styles (simplistic assumptions uncritically accepted,

such as those associated with conspiratorial thinking, or whose information comes from

uncritical acceptance of media reports from celebrities, and others), and finally those for

whom the anti-vaccine movement represents a “life cause” often because they or

someone they know has suffered or fears a real or perceived vaccine injury. Regardless

of the motivation behind such fears and anti-vaccine sentiment, common fears and

concerns relevant to vaccines are evident and therefore are the subject of this Perspective.

We believe that clinicians should be aware of these issues so that they might have an

educational role in dealing with these concerns, fears, and misconceptions. While we

hope this information benefits clinicians dealing with individuals from across the

spectrum of concern, many of our comments are focused specifically on those at one end

of the spectrum that we would label as “anti-vaccine.”

The title of this article emphasizes the communication divide that exists between

scientists/clinicians and anti-vaccinationists. We have found (and we have heard the same

from our colleagues) that discussions with anti-vaccinationists are otherworldly and alien

as the anti-vaccinationists reject the scientific method and the peer-reviewed literature.

Given that many of the claims of anti-vaccinationists appear to be immunological in

content, it is fitting that clinicians have an understanding of the anti-vaccinationists’

claims as well as references to the evidence that refute those claims. Thus, with apologies

to Douglas Adams [12], we provide “The clinician’s guide to the anti-vaccinationists’

galaxy.”

We begin by acknowledging that experience and history convince us that we have little

hope of converting the true anti-vaccinationists into vaccine “adopters.” However,

clinicians can play a part in influencing health care practitioners, political leaders, the

media, the public, and ultimately patients and parents, to consider the scientific method

and peer-reviewed literature. Reassuringly, the evidence indicates that most individual

patients and, in the case of children, their parents—whether they follow the

recommended vaccine schedule or not—are seeking to weigh benefits and risks for their

children in an effort to do their very best for their children [13]. A recent survey shows

that more than 80% of parents report healthcare providers are among their top three

sources of vaccine information [14]. Providing patients the right information, at the right

time, will help them make informed decisions, and perhaps prevent undue influence by

anti-vaccinationists.

History of the anti-vaccine movement

Anti-vaccinationists have existed since the beginning of vaccine use. Edward Jenner and

Louis Pasteur faced fierce opposition to their vaccines for smallpox and for rabies,

respectively [15,16], just as proponents of variolation (deliberate controlled infection

with smallpox virus) did before them [17]. In Britain, by the 1850s, an anti-vaccination

league had formed to oppose compulsory smallpox vaccination, and in the decades that

followed, similar organized efforts arose across Europe and the United States; indeed,

there are marked similarities between the anti-vaccinationists of the 19th century and

those of today [15]. Examples of shared arguments across the ages include the ideas that

vaccines cause life-threatening disorders themselves, have highly toxic constituents, and

fail to impart durable immunity unlike the diseases they are designed to prevent [15].

Thus, we must understand that opposition began with the first vaccines and we should

expect it to continue—even in the face of overwhelming data and scientific evidence to

the contrary.

Unlike those of the 19th century, no individual or group today actually uses the term

“anti-vaccinationist” self-referentially. Instead, groups take on names such as Generation

Rescue, Global Research, Moms Against Mercury, SafeMinds, The Informed Parent, the

National Vaccine Information Center, Vaccination Liberation, and ChildHealthSafety

[18-20].

Indeed, some of the most strident anti-vaccinationist groups claim to support vaccination.

For example, the National Vaccine Information Center states in its “Frequently Asked

Questions” section that it is not “anti-vaccine” and it “supports the availability of the

safest and most technologically advanced vaccines [21].” Many anti-vaccination

organizations take on names to suggest that they are information resources rather than the

political action and advocacy groups that they are (e.g., the National Vaccine Information

Center, AskDrSears.com, VaccineInfo.net, Vaccination News, and ChildHealthSafety).

In this Perspective, we use the term “anti-vaccinationist” to specifically describe those

who oppose vaccines in an unscientific manner, and who, through their activities, reject

vaccines and vaccination and furthermore deny or unfairly disparage the peer-reviewed

scientific literature, the evidence at hand, the scientific method, and even the motives of

those who produce, recommend and provide vaccines.

Common false immunological claims

A foundational argument of anti-vaccinationists is that vaccines are unsafe, an idea that is

supported by those members of the public who feel that they or their loved ones were

injured by vaccines. We focus on three of their most common claims that vaccines cause

undue harm as a result of: 1) antigenic overload; 2) an unacceptable rate of autoimmune

disorders; and 3) less safe immunity than natural infections. As we discuss, these claims

are false, and we review the clear and unambiguous data against them. However, the

scope of the anti-vaccinationists go beyond these immunologic claims and we cannot

address all of them here. Of note, however, is that their “immunologic” rhetoric has

impinged upon a sister domain of allergen-immunotherapy and we encourage readers to

access Jason Behrmann’s well written article entitled, “The anti-vaccination movement

and resistance to allergen-immunotherapy: A guide for clinical allergists” [22].

Antigenic overload

Clinicians should be aware that a major recurring claim among anti-vaccinationists is that

children receive too many vaccines (“too many, too soon”) and that this results in

“antigenic overload.” Robert W. “Doctor Bob” Sears writes on his website, “Wait until

their (babies’) immune system is a little healthier before you overload them with so much

[23,24].” The concept of “antigenic overload” holds that humans (particularly infants and

young children) are incapable of responding safely to the “large number” of vaccine

antigens given. As an example of how widespread this notion is, among 236 parents

claiming at least one non-medical exemption for their children in Wisconsin, USA,

64.9% endorsed the statement that “I am concerned that children’s immune system (sic)

could be weakened by too many immunizations;” disturbingly, among 727 parents whose

children were up to date with the recommended vaccines, that statement was still

endorsed by 33.7% of parents [25]. The anti-vaccination argument further suggests that

the timing of the vaccines with regard to children is “too soon” for the “immature

immune systems” of infants and children who are not able to process multiple vaccine

antigens. The concept is simple, winsome and memorable to otherwise scientifically

uninformed parents. The anti-vaccinationists claim that antigenic overload results in a

“cytokine storm” or “immune cascade” that triggers adverse health events [26-28],

though no scientific evidence supports such concerns that vaccines result in an antigenic

overload that in turn triggers adverse health events. We distinguish this from the very

real—but very rare—immunologic phenomenon that vaccines can through antigenic

stimulation result in an IgE-mediated allergic or anaphylactic response; although again,

the latter is rare and not based at all on the volume of antigenic exposure [29].

While he failed to cite any data to support his concern for antigenic overload, “Doctor

Bob” Sears has capitalized on this claim [30]. In his 2007 book entitled “The Vaccine

Book: Making the Right Decision for Your Child [31],” Sears offers alternative vaccine

schedules that eliminate some vaccines and delay others, often for years after they are

currently recommended by the Advisory Committee on Immunization Practices, the

American Academy of Pediatrics, and the American Academy of Family Physicians

[30,31]. The book has been in the Amazon Top 100 sellers and has been publicized by

various high-profile celebrities including the chat-show host Oprah Winfrey on television

in the past and is currently on the Oprah website [30,32].

Four major lines of evidence counter the concerns for antigenic overload. First, from the

moment of their birth infants encounter numerous microorganisms and their antigens far

exceeding the antigenic exposure due to vaccines in quantity and variety [33,34]. Second,

pre-licensure studies of vaccine efficacy and safety include studies of the vaccines given

in combination with the other vaccines in the routine vaccine schedule [33,34]. The data

from these pre-licensure studies fail to support claims of overload in terms of symptoms

and signs of illness. Third, post-licensure studies involving tens of thousands to millions

of children receiving the vaccine similarly fail to indicate evidence of antigenic overload

or its consequences [33,34]. Fourth, infants and children actually receive far less

antigenic “exposure” today with the routine childhood vaccination schedule than they did

in the past [33,34]. For example, the smallpox vaccine given circa 1900 contained

approximately 200 proteins, and the whole cell pertussis component of the diphtheria-

tetanus-pertussis (DTwP) vaccine given in the United States up until the 1990s contained

approximately 3,000 proteins [33]. By contrast, the current United States schedule of all

15 recommended vaccines from birth to age 5 years amounts in total to no more than 150

proteins and polysaccharides [33].

Vaccines and autoimmunity

A second claim often promoted by anti-vaccinationists is that vaccines can result in

autoimmune diseases such as type 1 diabetes mellitus, multiple sclerosis and Guillain-

Barre syndrome (GBS)—despite the fact that multiple high quality studies have failed to

find systematic evidence of such associations. A recent Institute of Medicine review–by a

panel of experts reviewing more than 12,000 published reports, failed to find evidence for

the development of any of these three autoimmune diseases as a result of vaccines [35].

French public health authorities suggested an association between hepatitis B virus

vaccination in female adolescents and multiple sclerosis, and as a result suspended the

further use of the vaccine in this sub-group in 1998 [36,37]. Despite this fear, no

association was found, and the suspension was lifted. This was an embarrassment to the

French public health authorities who had banned the vaccine based on public pressure

and anti-vaccine fears of an association, rather than scientific data. No scientific

association has been reported between hepatitis B virus vaccination and severe

autoimmune diseases such as multiple sclerosis [35,38].

Similar studies have found no association between either multiple sclerosis or diabetes

mellitus and vaccination [35]. The generally described theoretical basis for these

autoimmune events is based on the hypothesis that a vaccine component “mimics” a

human protein or cell component (either by sequence or conformational homology), and

hence antibody produced to this vaccine component will also bind to its human analogue,

and thereby produce damage and disease (or autoimmunity) from either auto-antibodies

or T cells reactive to self-antigens. Such a mechanism of molecular mimicry as a cause

for vaccine-related autoimmune diseases has not yet been demonstrated for any U.S. or

European licensed vaccine component.

Nonetheless, rare temporal associations (not the same as causality) between

autoimmunity and vaccines do exist, such as the possible association between GBS and

the 1976 swine influenza virus vaccine [39], idiopathic thrombocytopenic purpura and

the measles-mumps-rubella (MMR) vaccine [40], Acute Disseminated Encephalomyelitis

(ADEM) and rabies vaccines made from rabbit CNS tissue [41] and myopericarditis and

the smallpox vaccine [42,43]. The last two disorders are also associated with the

respective wild-type virus infection and therefore it is not surprising that they are rare

consequences of vaccination. The mechanisms for such effects are unclear and the topic

of current study, and are likely different with regard to each vaccine, but to the extent

such effects do exist (on the order of one excess case per million doses given), they are so

rare that more thorough studies of these associations have been impossible owing to the

extremely low numbers of affected individuals, despite hundreds of millions of vaccine

doses given [44,45]. In an attempt to address this issue, a new field of study entitled

“adversomics” has developed. Adversomics aims to use the tools of immunogenetics,

systems biology, immune profiling and bioinformatics to discover individual and

common mechanisms for such vaccine side effects [46,47]. However, even with these

new techniques, it is still unlikely that rare side effects can be studied adequately owing

to the very, very low numbers of cases available for study.

As mentioned above, theoretically, molecular mimicry seems a possible mechanism

whereby a vaccine antigen could result in the development of an autoimmune

phenomenon, such as was proposed for the induction of arthritis after administration of

the Lyme disease vaccine. The potential mechanism for how Lyme vaccine could induce

arthritis has been recently discussed in detail [48], but can be simply summarized in that

no data, including two large controlled studies, support such concerns, and no evidence

supports the induction of arthritis by this vaccine [48-50]. In fact, the sheer volume and

diversity of antigens presented during “natural” infection support the counterclaim that

infections are more likely than vaccines to result in autoimmune phenomena, as is readily

clinically observed—such as influenza virus infection causing GBS [51] and

Campylobacter and other infections causing GBS [52]. It is therefore the case that

infections, rather than the vaccines that protect against such infections, are far more likely

to be potential inducers of autoimmune diseases [53,54].

Further, other immunologic consequences must result from vaccination if vaccines were

somehow to lead to autoimmunity. These include the presence of T and B cells reactive

to self, the presentation of self-antigens by HLA molecules in quantities sufficient to

trigger immune reactions to self antigens–including quantities sufficient to activate

autoreactive T and B cells, the down regulation of regulatory T cells that act to modify

autoreactive immune responses, the production of cytokines necessary to lead to

activation of autoreactive T and B cells, and others. Once antigen-bound autoantibodies

are produced they can bind with Fc receptors and induce activation of the complement

system. Either of these processes can cause activation of inflammatory cells and

production of proinflammatory mediators, presumably leading to autoimmune disorders.

To date, no evidence supports the idea that currently licensed vaccines lead to these

consequences. Additional concerns have been raised that newer vaccine adjuvants could

lead to some or all of the aforementioned phenomena [55]. While possible, no vaccine

adjuvants currently licensed in the U.S. or Europe have been attributed as causative of

autoimmune disease, and more data are needed as additional newer vaccine adjuvants are

developed [45].

Natural immunity versus vaccine-induced immunity

A third common claim made by anti-vaccinationists is that immunity induced by “natural

infection” is safer than vaccine-induced immunity. The data dispute such claims. For

example, as discussed previously, the risk associated with developing GBS associated

with the influenza virus vaccine could plausibly be as high as one case per million doses

of vaccine administered [56] – though no such association has been confirmed since the

1976 pandemic vaccine [35]. By contrast, in the United States wild influenza virus kills

approximately 1 in every 8,300 Americans per year (predominantly older persons), and in

the United States from 2009-2010, the pandemic H1N1 influenza virus infection resulted

in the loss of 2,000,000 years of life [57]. The influenza virus vaccine does not cause

myocarditis, pneumonia, bronchitis, sinusitis, or significant amounts of lost work and

school time, whereas it is quite clear that “natural” influenza can—and does—commonly

cause these preventable morbidities.

Although wild “natural” virus infection can lead to superior immunity, per se, compared

to vaccine-induced immunity at the individual level, a quantifiable price is paid by the

population for only a small gain. For example, “natural” measles virus infection in an

otherwise healthy host provides lifelong immunity but causes death in about 1 out of

every 3,000 cases, as well as myriad other non-lethal and disabling complications. By

contrast, the measles vaccine is, when appropriately administered as licensed, not

associated with death (or at least despite billions of doses of vaccine having been

administered, a risk of death is not detectable by statistical methods), or with other

measurable complications of a life-threatening nature. In addition, with many, but not all,

vaccines, the administration of booster doses can overcome the possibility of shorter-

lived immunity induced after only one or two doses of vaccine. Furthermore, this is

relevant at the public health level as those children and adults with immunocompromising

illnesses cannot receive live viral vaccines, and therefore depend upon high coverage

rates of the measles vaccine and high levels of immunity in the general population (so-

called “herd immunity”) for protection from natural infection.

In the case of varicella (chickenpox), it is recommended that all children in the United

States receive two doses of vaccine. The latest data (2009) from the National

Immunization Survey shows that 89.6% of all children 19 to 35 months of age have

received their first dose; the second dose is due at 4-6 years of age, but we have no

national figures on the rate of uptake of the second dose [58]. Before we began routine

vaccination against it, wild varicella zoster virus infection was the most common cause of

vaccine-preventable death among children in the United States [59]. From 1990 to 1996,

an average of 103 deaths from varicella were reported each year in the United States;

since the addition of the vaccine to routine childhood immunizations in 1995, the number

of deaths has been declining each year [60]. This compares with approximately 25 deaths

a year in England and Wales, where routine vaccination against chicken pox is not

practiced [61]. Furthermore, a major risk worth considering is that once infected with

wild varicella zoster virus, infection becomes latent and chronically persistent in all

persons infected. This results in the development of herpes zoster (shingles) in 20–30%

of infected people later in life when reactivation of the virus occurs due to stress,

immunocompromise or immunosenescence. By contrast, the rates of herpes zoster

following varicella vaccination are substantially lower than after natural infection [62-

64].

Thus, in summary, studies support the overall immunologic safety of routine childhood

and adult vaccinations. No data support the concept of antigenic overload, and we are in

fact exposing individuals to fewer antigens with the current vaccinations than in decades

past. Although rare phenomena suggestive of autoimmune sequelae have temporally

occurred in association with routine vaccination, these risks, even if real, are dwarfed by

the benefits of vaccination as well as the recognition that such autoimmune phenomena

are more likely to occur after natural infection than after vaccination. Finally, the nature

of the immunity offered by a vaccine against wild disease is sufficient to prevent

infection and is far more safely obtained than immunity from natural infection.

Harms done by the anti-vaccine movement

We would be remiss to discuss these fallacies of the anti-vaccine movement without also

addressing the impact that such fallacies have upon vaccination efforts. Public health

officials hail routine vaccination as one of the top ten public health achievements of the

20th century [65], but anti-vaccinationists have successfully campaigned to block

legislation for school and day-care mandates and other public health interventions

designed to increase vaccination uptake. For example, it has been documented that

pressure from the anti-vaccine movement worldwide resulted in nations that discontinued

use of the pertussis vaccine, with 10 to 100 times more morbidity and mortality from

pertussis than the countries that continued vaccination [66]. “Doctor Bob” Sears’

alternative vaccination schedule has resulted in significant under-vaccination, putting

children at risk from circulating diseases, which is measurable in terms of increased rates

of measles and pertussis [7,30,67,68]. Similarly, the impact of Andrew Wakefield, now

widely recognized as fraudulently claiming an association between the measles virus

vaccine and autism (see below), is evident in the perceptions of parents choosing to

exempt their children from vaccination; in a Wisconsin survey of parents who refused

vaccination, 31% reported their reason for concern was autism [25]. Anti-vaccinationists

create among otherwise informed and willing parents hesitancy that results in delay and,

in turn, disease outbreaks [7,66,69]. With relatively cheaper and more global means of

communication through the Internet, anti-vaccinationists now have the opportunity to

spread their message more extensively [70,71].

The impact of the anti-vaccinationists is not just a problem of wealthy countries, but

threatens developing countries as well through the use of the Internet, which publicizes

their false claims and lowers public confidence in vaccination throughout the world; this

further raises the risk of pandemics and extensive outbreaks [72]. But most

investigations into the psychosocial aspects of vaccination acceptability so far have been

carried out in industrialized nations, and attention must be given to developing countries

in this respect [73].

Most recently, the anti-vaccine movement readily and uncritically endorsed and accepted

the fraudulent claims of Andrew Wakefield that receipt of the MMR vaccine was related

to the development of autism spectrum disorders. In 1998, Wakefield and colleagues

published in The Lancet an article entitled, “Ileal-lymphoid-nodular hyperplasia, non-

specific colitis, and pervasive developmental disorder in children [74].” The article

claimed to report a newly identified association “of a pattern of colitis and ileal-

lymphoidnodular hyperplasia in children with developmental disorders.” Furthermore,

while admitting they did not “prove an association between measles, mumps, and rubella

vaccine and the syndrome described,” they proposed the possibility of a causal link and

furthermore suggested that we might find an increase in the syndrome they described

following the introduction of the MMR vaccine [74]. The authors went on to state that

virological studies were underway to test for a causal association between the MMR

vaccine and the syndrome described [74].

Later in a comment in The Lancet [75] published in 1999, Wakefield cited a virology

study published in 1995 as evidence for an association between measles virus and chronic

intestinal inflammation [76]. In an effort to claim scientific rigor and academic integrity

and accuse another of lacking both, he also cited a second study in which he participated

from 1998 that did not detect measles virus RNA in inflammatory bowel disease [77].

However, to counter the negative study, he then cited a third study which he stated was

strongly positive [78].

Wakefield’s claim of a lack of scientific rigor and of academic integrity was directed at

the authors of one of the early epidemiological studies that demonstrated the lack of an

association between MMR and autism [79]. In his argument, Wakefield used autism-

incidence data from the UK and California (USA) to show what he claimed were

“identical temporal trends …with the rise in autism from a steady baseline value,

coinciding with the introduction of MMR vaccine as the single strategy in both countries

that use the same diagnostic criteria for autism.” This was followed by a report co-

authored by Wakefield in 2000 that this new autism-variant has certain features

characteristic of persistent measles virus infection [80].

Numerous studies followed, however, demonstrating no association between MMR

vaccination and autism [79,81-89]. Despite these studies and evidence-based

recommendations to dismiss the claims made by Wakefield by the U.S. Institute of

Medicine [90] and others [91], and despite an early comment by investigators at the

U.S. Centers for Disease Control and Prevention warning of the possibility of a

cataclysmic “snowballing” of concern resulting from this publication, pandemonium

ensued [81]. Such claims have now been thoroughly debunked, and Wakefield has

been stripped of his medical license and censured [92-94]. Nonetheless, many from the

anti-vaccine movement consider Wakefield a hero of the cause, and refuse to accept

such data as fatally flawed and untrue. Indeed, J. B. Handley, co-founder of the autism

support group called Generation Rescue, which disputes vaccine safety, told reporters,

“To our community, Andrew Wakefield is Nelson Mandela and Jesus Christ rolled up

into one ... He’s a symbol of how all of us feel [95].” Michael Shermer has written

about this phenomena of why people have and maintain beliefs, despite data to the

contrary, and has termed such phenomena “belief-dependent realism” (beliefs come

first, explanations are then constructed to support such beliefs) composed of two

processes: patternicity (finding meaningful patterns in meaningful and meaningless

data), and agenticity (infusing patterns with meaning, intention, and agency). This, he

maintains, leads to a positive feedback loop of belief confirmation, despite ample data

challenging such beliefs, and a cognitive process that convinces one their beliefs are

truths [96]. One of us (GAP) has written about the cognitive biases and preferred

cognitive styles people use in thinking about vaccines, and we have recommended

approaches to dealing with these different styles [97].

Over the past 13 years since Wakefield first made these claims, the U.K., the U.S.,

Western Europe and other countries have experienced a decrease in measles and MMR

vaccine uptake concomitant with increased rates of measles and mumps outbreaks [98-

101]. Currently, in 2011, Europe is suffering major outbreaks of measles numbering more

than 10,000 now in France and thousands more across the continent resulting in

transmission to other continents including the Americas, Australia, and New Zealand

[102-106]. The outbreaks in Europe now involve 33 countries. Even now—with the

recognition that Wakefield had defrauded The Lancet, its readers, the scientific

community, and the public—there are continued worries, even among a large percentage

of parents whose children are up to date with the recommended vaccines, that vaccination

might cause autism. Why do such concerns persist? Autism only becomes clinically

apparent at an age typically only after a substantial number of vaccines are given, thus

making vaccines suspect. Why vaccines? They are, for that parent, one of the few, if not

the only, technologically sophisticated “treatments” the infant has received since birth.

Why autism? It has emerged on the vanguard of parents fears; it is a devastating

condition with no cure or prevention and really no understanding of its cause.

The problem, however, is bigger than the concern for autism. In a comparison of parents

claiming non-medical vaccine exemptions for their children with parents of vaccinated

children in the U.S., substantial percentages of parents in both groups had persisting

concerns about vaccine safety, particularly with relation to their benefits [25]. In a recent

national survey, nearly 80% of primary care physicians in the United States reported at

least one vaccine refusal a month and 8% of physicians reported that more than 10% of

their patients’ parents refused vaccination [107]. Furthermore, perhaps fueled by fears of

“antigenic overload” and by “Doctor Bob” Sears’ alternative schedule [30,31], nearly

90% of primary care physicians reported at least one request for spreading out vaccines

and 20% reported that more than 10% of their patients’ parents had requested this [107].

Spreading out childhood vaccination can result in a delay in achieving immunity,

permitting both a personal lack of protection as well as decreasing herd immunity. This is

combined with the human tendency for delays to result in omissions and, for some

vaccines, a delay might result in the inability to receive the vaccine at all (e.g., rotavirus

vaccine has maximal ages for both starting and completing the series.)

Conclusions and call to action

Current data across all vaccines, across all age groups, and across all formal

recommendations, indicate that vaccines are overwhelmingly safe in the vast majority of

patients for whom they are recommended, and that they are effective and appropriate for

the recommended use in each age group [35]. We recognize that no man-made product,

including vaccines, is absolutely and completely safe or perfectly effective, but at both

the individual and population levels vaccines that are licensed for use in the United States

and elsewhere demonstrate extraordinarily high levels of safety and extremely rare rates

of serious life-threatening side effects, with correspondingly great individual and

population-level benefits. Anti-vaccine concerns centered around false immunological

claims of harm or antigenic overload are specious and without scientific data to support

such claims. On the contrary, the available scientific data richly support the

immunological value of vaccines in substantially decreasing morbidity and mortality

owing to infectious diseases, and in improving the health of both individuals and

populations. Misinformation and lack of scientific understanding must be countered for

the public good, and the false information anti-vaccinationists spread countered. It is

hoped that clinicians can and will lend their expertise to this issue for the good of the

public health by first being informed themselves, and second, countering the false

immunologic claims commonly promoted by anti-vaccine groups. This commentary

provides a basic review of three of the most common anti-vaccine claims, and hence

could serve as an outline of topics that could inform further research, teaching seminars,

and continuing education courses for clinicians. By being informed about the charges

brought forward by anti-vaccine proponents, especially those of a quasi-immunological

nature, clinicians can assist in providing data-driven information to health providers and

the public, assist in research where data gaps are apparent, and provide data for the

scientific basis for accepting or refuting claims of vaccine safety and function. The only

rational way in which to proceed in devising individual and public health policy in

regards to the use of vaccines requires high quality studies and resulting data, interpreted

carefully and based on the scientific method. In this regard, physicians have a duty and

an important role to play in education, and the public health and vaccine debates.

Disclosures: Dr. Poland is the chair of a Safety Evaluation Committee for an investigational vaccine trials being conducted by Merck Research Laboratories. Dr. Poland offers consultative advice on new vaccine development to Merck & Co., Inc., Avianax, Theraclone Sciences (formally Spaltudaq Corporation), MedImmune LLC, Liquidia Technologies, Inc., Emergent BioSolutions, Novavax, Dynavax, EMD Serono, Inc., Novartis Vaccines and Therapeutics and PAXVAX, Inc. Doctor Jacobson is a member of a safety review committee for a post-licensure study funded by Merck & Co. concerning the safety of a human papillomavirus vaccine. He is also a member of a data monitoring committee for an investigational vaccine trial funded by Merck & Co. He also serves as a principal investigator for two studies, including one funded by Novartis International for its licensed meningococcal conjugate vaccine and one funded by Pfizer, Inc. for its licensed pneumococcal conjugate vaccine.

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