E

SD

a

ARRAA

KACIV

1

t[ibho[gaamho

TCB

T

0d

Vaccine 29 (2011) 1874–1880

Contents lists available at ScienceDirect

Vaccine

journa l homepage: www.e lsev ier .com/ locate /vacc ine

merging and continuing trends in vaccine opposition website content�

andra J. Bean ∗

epartment of Public Health, College of Health and Human Sciences, 401 Waldo Hall, Oregon State University, Corvallis, OR 97331, United States

r t i c l e i n f o

rticle history:eceived 13 October 2010eceived in revised form 1 January 2011ccepted 5 January 2011vailable online 14 January 2011

eywords:nti-vaccine websitesontent analysis

nternetaccine opposition

a b s t r a c t

Context: Anti-vaccination websites appeal to persons searching the Internet for vaccine information thatreinforces their predilection to avoid vaccination for themselves or their children. Few published studieshave systematically examined these sites.Objectives: The aim of this study was to employ content analysis as a useful tool for examining and com-paring anti-vaccination websites for recurring and changing emphases in content, design, and credibilitythemes since earlier anti-vaccination website content analyses were conducted.Methods: Between February and May 2010, using a commonly available search engine followed by adeep web search, 25 websites that contained anti-vaccination content were reviewed and analyzed for24 content, 14 design, and 13 credibility attributes.Results: Although several content claims remained similar to earlier analyses, two new themes emerged:

(1) the 2009 H1N1 epidemic threat was “manufactured,” and (2) the increasing presence of so-called“expert” testimony in opposing vaccination.Conclusion: Anti-vaccination websites are constantly changing in response to the trends in public healthand the success of vaccination. Monitoring the changes can permit public health workers to mount pro-grams more quickly to counter the opposition arguments. Additionally, opposition claims commonlyappeal to emotions whereas the supporting claims appeal to reason. Effective vaccine support may be

g mo

better served by includin

. Introduction

Vaccines are the most important public health achievement ofhe last century [1], saving as many as 3 million lives each year2]. For example, smallpox, now eradicated, once killed 30% ofts victims and, in 1967 when the global eradication campaignegan, still infected 10–15 million persons a year [3]. As vaccinesave become increasingly available to combat a growing numberf pathogens, vaccine-preventable diseases (VPDs) have declined4–6]. Many countries have instituted mandatory vaccination pro-rams as public health measures, but the U.S. has not done so onnational level and vaccination policy and practice varies by state

nd within states. All states permit opting out of vaccines using aedical objection or for religious reasons [7]. In addition, 21 states

ave relaxed the religious exemption to include a philosophicalpt-out choice for pediatric and other vaccinations [4,8]. Of these

� This findings from this analysis were presented at two conferences in 2010:he American Association for the Advancement of Science, Pacific Division, Annualonference, June 14, 2010; and a slightly different version at the Association forahá’í Studies annual conference, Vancouver, B.C., August 14, 2010.∗ Present address: 5516 SW Willow Ave, Corvallis, OR 97333, United States.

el.: +1 541 753 0602; mobile: +1 404 281 7185.E-mail address: beans@onid.orst.edu

264-410X/$ – see front matter © 2011 Elsevier Ltd. All rights reserved.oi:10.1016/j.vaccine.2011.01.003

re emotionally compelling content.© 2011 Elsevier Ltd. All rights reserved.

21 states,1 several have experienced lower than 70% immuniza-tion rates for children under the age of 2 years, including Idaho,Oklahoma, and Oregon.2 Although a recent report from the U.S.Centers for Disease Control and Prevention (CDC) notes an overallhigh level of vaccination for children ages 19–35 months, pocketsof low vaccination levels still exist as shown on the state-by-statetables [9]. Low vaccination rates and resulting outbreaks of vaccine-preventable diseases have been shown to be geographically relatedto pockets of vaccine opposition [4,10,11]. Vaccine opposition isa social movement, fueled in part by anti-vaccine information onthe Internet [12–16]. Well-organized advocacy groups, the growingpopularity of alternative health care, and new rapid communica-tion technologies have all contributed to geographical clusters oflower vaccination rates [11,17].

Although health care providers are the primary source for med-

ical advice, including vaccination advice [18,19], the public isincreasingly turning to other sources, including the Internet. Tra-ditionally, the public has received information from the printedpage, radio, and television. One advantage of these traditional com-

1 Arizona, Arkansas, California, Colorado, Idaho, Louisiana, Maine, Michigan,Minnesota, Missouri, New Mexico, North Dakota, Ohio, Oklahoma, Oregon, Penn-sylvania, Texas, Utah, Vermont, Washington, Wisconsin.

2 http://www.cdc.gov/vaccines/stats-surv/nis/data/tables 0809.htm.

S.J. Bean / Vaccine 29 (2011) 1874–1880 1875

Table 125 websites containing anti-vaccination messages examined (comprehensive list).

Vaccination—silenced witnesses www.whale.to/vaccines.htmlVaccine Risk Awareness Network http://vran.orgThe Vaccination Files http://home.iae.nl/users/lightnet/health/vaccination.htmVaccine Dangers http://educate-yourself.orgVaccination—Deception and Tragedy www.shirleys-wellness-cafe.com/vaccines.htmVaccines—Children’s vaccines http://healing-arts.org/children/vaccinesNational Vaccine Information Center www.nvic.orgVaccine Risk Awareness Network www.vaccineriskawareness.comVaccine Information www.vaccinetruth.orgVaccination Information Serving Australia www.visainfo.org.auVaccine Safety Website www.vaccines.netVaccine Information and Choice Network www.nccn.net/∼wwithin/vaccine.htmVaccination Liberation www.vaclib.orgGlobal Vaccine Awareness League http://www.gval.comHealthy Child—this site links from: immunization Awareness Society (NZ) http://www.healthychild.com/vaccinations/ http://www.ias.org.nzJustice Awareness and Basic Support (JABS) http://www.jabs.org.uk/Moms Against Mercury http://www.momsagainstmercury.orgMedicine-No: Vaccinations http://www.medicine-no.com/Vaccinations.htmThe Douglass Report http://douglassreport.comDr. Joseph Mercola http://newsletters.mercola.com/ReferralProgram/

mYbdi

nb[nNatcnst[mbjtoiartth

2

trt

(

o

outs examined at least three times using criteria established in a1998 content analysis of print media [28]. Later content analyses

Australian Vaccination NetworkThe Informed ParentVegan FamilyVaccination Information Service

ercial information sources is their financial stake in truthfulness.et increasingly, all media—including the Internet—sensationalizeoth vaccine objections and vaccine adverse events. One sourceates the emergence of the “vaccine-damaged child” as a new med-

cal entity to a television program broadcast in 19823 [20].As a new source of information, the Internet is as indiscrimi-

ate as were the earliest medieval broadsheets, and anything cane published by anyone willing to take the time to launch a website12]. In 2009, more than 175 million Americans searched the Inter-et for health information, a six-fold increase since 1998 [21]. Theational Center for Health Statistics reported that in 2009, 46% ofdults older than 18 years of age searched for health information inhe previous 12 months [22]. Anti-vaccination messages are moreommon on the Internet than in print or broadcast and the Inter-et may be more likely to contain unverified information [12]. Onetudy found that a search on the word “vaccination” was more likelyo produce a list of anti-vaccination than pro-vaccination websites23]. This results in an increased possibility of misleading infor-

ation on vaccines and, thus, vaccination decisions may be madeased on such misleading information [12]. In a German study, sub-

ects viewing anti-vaccine websites for only 5–10 min increasedheir perceptions of vaccination risks, decreased their perceptionsf the risks of avoiding vaccination, and lowered their vaccinationntentions compared to viewing neutral websites [24]. The contentnd design of websites with anti-vaccination content promote andeinforce existing beliefs that vaccines are harmful. Blume reportshat the messages on these sites can encourage parents to find wayso avoid vaccines, especially for their children, despite advice fromealth care providers to vaccinate their children [14].

. Methods

The aim of this study was to employ content analysis as a usefulool for examining and comparing anti-vaccination websites for

ecurring and changing emphases in content, design, and credibilityhemes since earlier website content analyses were conducted.

On February 2, 2010, a search was conducted using Google®

Google, Inc., Mountain View, CA), the most popular Internet

3 “DPT: Vaccine Roulette,” broadcast on NBC affiliate WRC-TV in Washington, D.C.,n April 19, 1982.

http://www.avn.org.au/avnhttp://www.informedparent.co.uk/http://www.vegfamily.com/vaccines/are-vaccines-vegan.htmhttp://www.vaccination.inoz.com/links.html

search engine and one likely to be used by parents. One separatesearch was conducted for each of 10 keywords: vaccine, vacci-nate, vaccination, immunize, immunization, immunise, immunisation,anti-vaccination, anti-immunization, and anti-immunisation follow-ing the Wolfe et al. protocol from 2002 [16]. One study found that97% of the time, online information seekers examine only the first10 search results [25]. Limiting the list to the top 10 hits producedjust four distinct websites. One of these four sites, The Millenium(sic) Project4, was an Australia-based self-described clearinghouseto “uncover promoters of quackery and those who lie about the dan-gers of vaccines.” A search on that site resulted in 33 anti-vaccinesites beginning with or containing the word “vaccine” or “vaccina-tion” in the title [26]. After eliminating duplications, broken links,blogs, and authored articles, just 15 websites remained from thisclearinghouse search. Authored articles were omitted to simplifythe content analysis and did not, in any case, fit the “design” domaincriteria.

On March 26, 2010, a “deep web” search was conductedusing the word “vaccination” and 17 search engines.5 The webcan be thought of as divided into “surface” and “deep” web.The surface web comprises static and fixed pages created anduploaded to a server. The deep web consists of dynamic pagescreated as a result of a database search [27]. In the currentstudy, most of the resulting sites from a deep web search onthe above keyword contained peer-reviewed journal articles,other academic information, or general news. The Open DirectoryProject (http://www.dmoz.org/Society/Issues/Health/), however,produced 10 additional relevant anti-vaccine websites, to total 25and the addition strengthened this study. These 25 websites arethought to be exhaustive. Home pages, varying in length (1–22pages, with most at 1–5 pages [n = 16]), were chosen for analysisbecause of convenience. Home pages were printed and the print-

of websites used many of the themes established in the 1998 con-tent analysis, but expanded upon them and classified them into

4 http://www.ratbags.com/rsoles/.5 Surfwax, Academic Index, Clusty, Dogpile, Multiple Search, Mamma, World

Curry Guide, Fazzle.com, Deep Dyve, OAIster database, Mooter, Northern LightSearch, Complete Planet, The Scout Archives, Daylife, Silobreaker, and WWW VirtualLibrary.

1876 S.J. Bean / Vaccine 29 (2011) 1874–1880

Table 2Content attributes (25 websites examined).

n % % Davies % Kata % Wolfe(n = 100) (n = 8) (n = 22)

Safety and effectivenessPoisons, additives, or ingredients 16 80 79 100Vaccines cause idiopathic illness, damage, or death 19 76 99 100 100Vaccines erode immunity 8 32 54 88 95Multiple simultaneous vaccines increase risk 3 12 38 50Under-reporting of reactions 9 36 63 95Vaccines are ineffective/temporary 8 32 83 81Use of aborted fetal tissue 2 8 32Diseases have declined 8 32 57 88 73

Civil libertiesViolation of civil liberties 11 44 77Parental rights 4 16 75Totalitarianism 5 20 79 63

Alternative treatmentsAlternative treatments 5 20 45 88 70Critiquing biomedicine 1 4 75Implied debate 4 16 27 38“Back to nature” 6 24 41 88

Conspiracy theories/search for truthProfit/conflict of interest 13 52 62 75 91Collusion 5 20 63Government secrecy or cover-ups 5 20 88 75Manufactured threat 11 44Rebel doctors 1 4 56 50Fear-mongering 2 8 39 50Unusual theories, if unique theories about the purposes of vaccination were presented 4 16 38Privileged information 2 8 50Informed choices 6 24 86 38

Table 3Design attributes (25 websites examined).

n % % Davies % Kata % Wolfe(n = 100) (n = 8) (n = 22)

Emotive appeals 19 76 99Personal testimonies 8 32 88 55Professional testimony from MDs and other experts 13 52Images of “scary needles” 9 36 13 32Images of damaged kids 6 24 50 23Commercialism, promoting purchases 11 44 75 43Solicitations for contributions 6 24 63How to avoid vaccinating 8 32 64Negative links 14 56 100 100Positive links 6 24 31 50 45Chat rooms 7 28 40Adverse vaccine event reporting 5 20 25Authority/official status 3 12 27 25Legal vaccine exemptions 2 8 50

Table 4Credibility attributes [30] (25 websites examined).

n % % Davies % Kata % Wolfe(n = 100) (n = 8) (n = 22)

Non-partisan claims, if site alleges to present both sides of the issue 8 32 33 25Unbiased, if site actually presents both sides of the issue 1 4 15 13Disclosure of authors, sponsors, developers 4 16Disclaimer 9 36Attribution and documentation 3 12Accessibility and availability 16 64Currency of information 3 12Contact addresses 17 68User support (includes availability of support, documentation for users) 4 16Outdated sources, if the sources are outdated or have been disproven 2 8 75Misrepresentations, if sources are not used truthfully or false conclusions are drawn 4 16 88

Self-reference, if links are to anti-vaccination “experts”No references, if no statistics or citations are provided to support the data

5 20 75 882 8 38

29 (2

cTtteaoaCa

3

t[Wuittcvses

scc

3

htasr[fvtt

3

fo

iiwiwlda

n

Uah

S.J. Bean / Vaccine

oding domains of content, design, and credibility [12,16,29,30].hese three domains were employed in the current study. Addi-ional data-driven themes emerged iteratively (i.e., “manufacturedhreat” and “authority/official status”) as the homepages werexamined and re-examined. The result comprised 24 contentttributes, 14 design attributes, and 13 credibility attributes. Eachf the 51 attributes was coded as absent or present (if it appearedt least once on the website) and entered into Excel® (Microsoftorp., Redmond, WA) spreadsheets for ease in analysis. Numericalnd percentage totals were tallied for each attribute and website.

. Results

Each of the websites in two previous anti-vaccine website con-ent analyses were examined—100 sites noted by Davies et al.12] and 8 sites listed in the Kata study [29]. For a third study by

olfe et al., the actual URLs for the websites analyzed (n = 22) werenavailable, so an exact comparison was not possible [16]. Dur-

ng a May 23, 2010, search conducted on all 100 of the websites inhe Davies study [12], 3 were found to be duplicate listings, 62 ofhe remaining 97 websites had vanished entirely and 20 no longerontained vaccine content on the home pages, leaving a total of 35iable websites from the original 100. Five of the 8 sites in the Katatudy [29] were same as in the current study, and 11 of the sitesxamined in the Davies study [12] were the same as in the currenttudy.

All websites examined in this study are listed in Table 1. Theummary of results according to themes is found in three tables:ontent attributes are in Table 2, design attributes in Table 3, andredibility attributes are in Table 4.

.1. Content themes

Several content variables were similar to earlier findings, somead changed in intensity, and two new themes had emerged. Con-ent attributes are grouped into four subcategories (Table 2): safetynd effectiveness, civil liberties, alternative treatments, and con-piracy theories or search for truth. None of the 25 sites mentionedeligion specifically, so this domain, present in an earlier analysis29], was not included, nor were a number of other themes missingrom the current analysis. Many sites noted or linked to other anti-accine websites, and some linked to public health sources such ashe U.S. Centers for Disease Control and Prevention, and especiallyo the Vaccine Adverse Event Reporting System (VAERS).6

.1.1. SimilaritiesThe number of content attributes on each of the websites ranged

rom 1 to 10. This is similar to Wolfe’s finding that the total numberf claims per site ranged from 2 to 11 [16].

Safety and effectiveness. An overwhelming 76% of all websitesn this study included content that asserted that vaccines causellness, damage, or death. This is similar to Kata’s findings, in

hich all 8 sites contained the theme of “vaccines cause idiopathicllness, damage, or death” [29]. These illnesses and disabilities

ere often specifically listed on the websites, and ranged fromearning disabilities, asthma, and diabetes, to autism, attention

eficit-hyperactivity disorder, and Down Syndrome [31], to namefew.

Civil liberties. Forty-four percent of the websites in this studyoted that vaccine mandates were an example of excessive gov-

6 The Vaccine Adverse Event Reporting System (VAERS) was created by the.S. Food and Drug Administration (FDA) and the CDC to receive reports aboutdverse events which may be associated with vaccines. Information available at:ttp://www.fda.gov/cber/vaers/vaers.htm.

011) 1874–1880 1877

ernment control, a decline that may simply be an artifact of ratingrather than a true decline. A violation of civil liberties as associatedwith mandated vaccination (totalitarianism) appeared in 79% of thesites studied by Davies et al. [12], 77% of those in the Wolfe study[16], and on 6 of the 8 sites in the Kata study [29].

Alternative treatments. Just 20% of the sites in the current studyspecifically mentioned homeopathy, chiropractic, or other alter-natives to vaccination, a major decline from 88% as reported byKata [29], 45% by Davies et al. [12], and 70% by Wolfe et al.[16]. One website noted, without any scientific support for thisclaim: “Homeopathy is also noted for its success to antidote (sic)or remove the toxic effects of vaccines and to re-establish balancein the organism and restore health” (http://www.shirleys-wellness-cafe.com/vaccines.htm).

Poisons, additives, and ingredients. This theme was present on80% of the sites in the current study. It appeared only as “poi-sons” in all 8 of the sites examined by Kata [29] and was notincluded at all in the Wolfe study [16]. Ingredients in the web-sites examined in the current study were often specifically listedand may denote a new level of sophistication in these Internetsites. Mercury and aluminum compounds were often pinpointedas particularly suspect. One website noted that vaccines oftencontain “Aluminum which is associated with Alzheimer (sic) dis-ease and seizures also cancer producing (sic) in laboratory mice”(http://www.home.iae.nl/users/lightnet/health/vaccination.htm).

Financial motives. Allegations of vaccination being conductedsolely for financial gain or that vaccinations were promoted bythose with conflicts of interest appeared on 52% of the sites in thecurrent study, a decline from 88% found by Kata [29], 91% by Wolfeet al. [16], and 62% by Davies et al. [12]. This representative quotefrom a website makes an unsubstantiated claim that vaccines are amajor profit source for pharmaceutical companies, despite the factthat many of those companies have found vaccines to be increas-ingly unprofitable [32,33]. “Vaccines have become a billion-dollarmoney game, plain and simple. Drug companies have used scare tacticsto convince people to be injected with junk concoctions that, in somecases, are causing far more health problems than they are preventing”(http://douglassreort.com/reports/vaccines).

“Conspiracy theories and search for truth”. In the current study,84% of the sites mentioned at least one of the 9 subthemes in thiscategory,7 compared to 75% in Kata’s analysis [29] and 98% of sitesmentioned by Davies et al. [12]. Wolfe noted no specific mentions ofconspiracy theory [16]. The theme of government secrecy or cover-ups indicates a distinct distrust of authority in vaccine opposition[34].

3.1.2. DifferencesSeveral differences were apparent between the current and

earlier studies. The theme that adverse vaccine reactions areunderreported—present on 95% of websites studied by Wolfe et al.[16] and 63% of websites in the Kata study [29]—was present ononly 36% of the current study websites. A possible explanation forthis decline may be the greater awareness and use of VAERS forreporting any negative event following vaccination.

An argument that is also disappearing is “use of aborted fetaltissue.” This theme appeared in 32% of Wolfe’s websites [16], nonein the Kata study [29], and in two websites (8%) in the current study.

3.1.3. New themesThe current study revealed two themes that had not appeared in

previous analyses of anti-vaccine websites. These included allega-

7 Profit/conflict of interest, collusion, government secrecy or cover-ups, manufac-tured threat, rebel doctors, fear-mongering, unusual theories about the purposes ofvaccination, privileged information, and informed sources.

1 29 (2

ta

w“Eanii[

3

T

5lrehrwMtm‘li(

wsat

3

r(wdawwd

mosfeocoohn

4

o

they share important commitments,“according to the theory ofcultural cognition [43,44]. “Cultural orientations condition indi-viduals’ beliefs about risk through a set of in-group/out-groupdynamics. When faced with conflicting claims and data, individ-

878 S.J. Bean / Vaccine

ions of a manufactured or exaggerated threat to boost vaccination,nd a heightened presence of so-called expert testimony.

The H1N1 outbreak of 2009 and the campaign to promoteidespread vaccination of vulnerable populations was deemed a

manufactured threat.” One website noted that “News reports fromurope are suggesting that all the hype and hysteria over swine flu wasmanufactured threat with no basis in reality” (http://vran.org). Thisew theme—one that emerged as a specific reaction to the H1N1

nfluenza vaccination promotion—was present on 44% of the sitesn the current study, but was absent from any of the earlier studies12,16,29].

.2. Design themes

All design attributes measured are listed and summarized inable 3.

Professional or expert testimony. Expert testimony appeared on2% of the sites examined in the current study, about the same

evel as observed by Davies et al. [12]. Neither Kata nor Wolfeeported professional testimony as a theme in the websites theyxamined [16,29]. Testimonials often appeared with photographs,inting at professional sponsorship or endorsement of the site, andarely with any contact information for the cited expert. One suchebsite included a quotation from an otherwise unidentified Dr.endelsohn, voicing a vague and unspecified “growing suspicion”

hat vaccination may itself be responsible for an increase in diseaseorbidity: “Paedetrician, Robert Mendelsohn, MD, voices his concern:

There is growing suspicion that immunization against relatively harm-ess childhood diseases may be responsible for the dramatic increasen autoimmune diseases since mass inoculations were introduced”http://vran.org).

Parent testimonials. Parental testimonials, on the other handhich once predominated, seem to be a declining presence on web-

ites. Parents’ stories about adverse vaccine effects on their childrenppear on 32% of the sites in the current study, much lower thanhat observed by Wolfe (55%) [16] and Kata (88%) [29].

.3. Credibility themes

Although there is no general agreement on credibility crite-ia for evaluating websites, the criteria used in the current studyincluded in Table 4) was adopted from a list used by Kim et al. [30],hich condensed criteria from 10 other studies. One way of quicklyetermining credibility is by locating disclosures of sponsorship oruthorship of the site contents and disclaimers as to whether theebsite can legitimately disseminate medical advice. Only 36% ofebsites in the current study contained disclaimers and only 16%isclosed sponsors or authors.

Another credibility criterion is whether the website knowinglyisrepresents or distorts the truth. One example of this appeared

n one website: “This film is produced and freely distributed by con-umer protector and public health expert, Dr. Leonard Horowitz andeatures the world’s leading vaccine expert, Dr. Maurice Hilleman,xplaining why Merck’s vaccines have spread AIDS, leukemia, andther horrific plagues worldwide” (http://www.shirleys-wellness-afe.com/vaccines.htm). This quote, seeming to link the then-headf Merck pharmaceuticals to vaccine-caused illnesses, was presentn the site as accessed in the first search on February 2, 2010, butad vanished by May 15, 2010 (further evidence of the dynamicature of anti-vaccine content on the Internet).

. Discussion

This study has several limitations, including that it examinednly English-language websites, and therefore may not represent

011) 1874–1880

the full spectrum of anti-vaccine activity on the Internet. In addi-tion, it was a cross-sectional study rather than longitudinal. A thirdlimitation is the absence of coders other than the author. Websitehome pages only were examined and not threads or hyperlinks. Thisstudy should be seen as a snapshot in time—from February to May,2010. Despite these limitations, the differences between this andearlier studies illumine the dynamic nature of the Internet itself. A30% annual change in web content can be expected (Kevin Yurick,personal communication, January 28, 2010). For example, that 64%of 97 websites in one study had vanished entirely or no longer con-tained vaccine content in a reexamination after 8 years providestestimony to the volatility of the Internet. Even within the time-frame of this study, some home pages had floated down to websitelinks and new home pages had replaced them. Some content hadvanished entirely. Other websites had not been updated for years.On some sites, arguments had rapidly shifted during the threemonths to reflect new information and new scientific challenges.It should be noted that much of the content predated the with-drawal of the 1998 article in The Lancet that arguably launched theautism-MMR vaccine argument [35,36]8 and the subsequent back-lash against the anti-vaccine movement in recent reports [35,37].The changing nature of arguments and themes found online shouldalert public health officials to the need to monitor anti-vaccine webcontent to keep abreast of the latest shifts in emphasis.

This study pinpoints several trends in anti-vaccine content onthe Internet, where content constantly shifts and new themesappear, and highlights new themes on websites with anti-vaccination content. The trajectory arguably leads from vaccinealarmism to lowered vaccination rates, to recent outbreaks of suchvaccine-preventable diseases as measles [6,38], mumps, whoopingcough [13,39], and chicken pox [4,11]—all illnesses with possi-bly serious individual and public health outcomes [40]. One newtheme is the increasingly heightened role of expert testimony onanti-vaccine websites, especially from alleged physicians. This is atroubling trend. Because parents are likely to follow the advice ofphysicians [41,42], the presence of testimony attributed to medi-cal doctors can persuade parents who are hesitant to not vaccinatetheir children.

Vaccine objectors take their responsibilities as parents seriously,and can be frustrated when their concerns are dismissed or ignoredby busy physicians. A parent who has accessed information on theInternet may feel uniquely qualified to advocate for or against arecommended treatment or vaccine and may believe she is betterinformed than her physicians. Such parents may reject epidemi-ologic and population-level risk studies arguing for vaccinationsand provided by their pediatricians or family doctors because thosestudies neglect to take into account parents’ specific experiences,unique health histories, and unique beliefs [29]. Simply arguingagainst the points raised on the anti-vaccine sites is unlikely tobe persuasive, nor is bombarding vaccine-opposers—even sophis-ticated ones—with studies published in the scientific literature [29].

5. Recommendations

People tend to endorse positions held by those “with whom

8 While in press, British Medical Journal began a special series by author BrianDeer that “exposes the bogus data behind claims that launched a worldwide scareover the measles, mumps, and rubella vaccine” (Deer, B. (2011). How the case againstthe MMR vaccine was fixed. British Medical Journal January 5, 2011. Retrieved January7, 2011, from http://www.bmj.com/content/342/bmj.c5347).

29 (2

ulwwtiatIt[

vecbtp

mpspicoucbsAsmapcmp(o

cslu

A

sJEaoar

R

[

[

[

[

[

[

[

[[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

S.J. Bean / Vaccine

als usually are not in a position to determine for themselves howarge particular risks. . . really are. Instead, they must rely on those

hom they trust to tell them which risk claims are serious andhich specious. The people they trust, naturally enough, tend to be

he ones who share their worldview” [emphasis added] [44]. Accord-ng to Kahan [43], information should be presented in a manner thatffirms people’s values. “People tend to resist scientific evidencehat could lead to restrictions on activities valued by their group.f, on the other hand, they are presented with information in a wayhat upholds their commitments, they react more open-mindedly”43].

The group with whom they share these commitments may beirtual—online—and this virtual community may override the influ-nce of health care providers or the concerns of the public healthommunity. Health educational efforts require that first a personelieves she needs information, and then is willing to listen, ando trust her informant—in this case, the public health clinician orrimary health care provider.

Campaigns to promote vaccine have successfully used fear as aotivator [45,46], but the rationale of cultural cognition argues for

ersuasion over fear. In this context, the public health communityhould employ scientifically sound, as well as emotionally com-elling, arguments that promote the public’s as well as each child’s

ndividual health. It may wish to enlist the help of parents withhildren who had fallen ill from a VPD to tell their unique stories tother parents. As Newman explained in the BMJ in 2003, “those ofs trying to maintain a broader public health perspective need toollect and tell our own stories” [47]. One example of scientificallyased and emotionally engaging communication is the booklet oftories of VPDs produced in 2009 by Texas Children’s Hospital [48].nother is the National Network for Immunization Information,ponsored by the American Academy of Pediatrics and nine otheredical professional societies and associations. This site featuresrolling slide show of images of children, descriptions of vaccine-reventable illnesses in lay terms, and information about diseaseontagion, the history of the vaccine, and vaccine timing [49]. Itsajor disadvantage is the density of text on the site. Another, more

ublic-focused website, is “the parents’ portal” on the CDC websitehttp://www.cdc.gov/parents/), which includes a six-minute videof moms talking about their vaccine concerns with a pediatrician.

The public health community and pediatricians might activelyounter negative content by providing alternative informationources, including lists of pro-vaccine websites, their own pub-ic health-focused anecdotes, and scientifically sound and easilynderstood risk-benefit scenarios to allay parents’ fears.

cknowledgements

I thank the two reviewers for their careful reading and exten-ive suggestions on an earlier version of this paper. I also thankoseph Catania, PhD, Professor, Peter Lachenbruch, PhD, Professormeritus, Department of Public Health, Oregon State University;nd Dwaine Plaza, PhD, Associate Professor, Department of Soci-logy, Oregon State University, for their mentorship, comments,nd suggestions. The author declares no conflict of interest in theesearch for this study.

eferences

[1] CDC. Ten great public health achievements—United States, 1900–1999. Mor-bidity and Mortality Weekly 1999;48(12):241–3.

[2] WHO. Vaccine-preventable diseases and immunization. Available from:

http://www.euro.who.int/vaccine/20081217 11; 2009 [cited 21.05.2010].

[3] CDC. Some common misconceptions about vaccination and how to respond tothem. Available from: http://www.cdc.gov/vaccines/vac-gen/6mishome.htm;2007 [cited 1.02.2010].

[4] Omer SB, Pan WKY, Halsey NA, Stokley S, Moulton LH, Navar AM, et al. Non-medical exemptions to school immunization requirements: secular trends and

[

[

011) 1874–1880 1879

association of state policies with pertussis incidence. Journal of the AmericanMedical Association 2006;296(14):1757–63.

[5] Girard DZ. Which strategy for pertussis vaccination today? Pediatric Drugs2002;4(5):299–313.

[6] Feikin DR, Lezotte DC, Hamman RF, Salmon DA, Chen RT, Hoffman RE. Individ-ual and community risks of measles and pertussis associated with personalexemptions to immunization. Journal of the American Medical Assocation2000;284(24):3145–50.

[7] University of Pennsylvania Center for Bioethics. Vaccination require-ments and exemptions. Available from: http://www.vaccineethics.org/issue briefs/requirements.php; 2009 [cited 5.08.2009].

[8] National Conference of State Legislatures. States with religious and philosoph-ical exemptions from school immunization requirements. Available from:http://www.ncsl.org/IssuesResearch/Health/SchoolImmunizationExemptionLaws/tabid/14376/Default.aspx; July 2010 [cited 14.10.2010].

[9] Wooten KG, Kolasa M, Singleton JA, Shefer A. National, state, and local areavaccination coverage among children ages 19–35 months—United States, 2009.Morbidity and Mortality Weekly Report 2010;59(36):1171–7.

10] Omer SB, Enger KS, Moulton LH, Halsey NA, Stokley S, Salmon DA. Geographicclustering of nonmedical exemptions to school immunization requirementsand associations with geographic clustering of pertussis. American Journal ofEpidemiology 2008;168(12):1389–96.

11] Omer SB, Salmon D, Orenstein WA, deHart P, Halsey N. Vaccine refusal, manda-tory immunization, and the risks of vaccine-preventable diseases. New EnglandJournal of Medicine 2009;360(19):1981–8.

12] Davies P, Chapman S, Leask J. Antivaccination activists on the world wide web.Archives of Disease in Childhood 2002;87:22–5.

13] Gangarosa EJ, Galazka AM, Wolfe CR, Phillips LM, Gangarosa RE, Miller E, et al.Impact of anti-vaccine movements on pertussis control: the untold story. TheLancet 1998;351(9099):356.

14] Blume S. Anti-vaccination movements and their interpretations. Social Science& Medicine 2006;62(3):628–42.

15] Cooper LZ, Larson HJ, Katz SL. Protecting public trust in immunization. Pedi-atrics 2008;122(1):1–5.

16] Wolfe RM, Sharp LK, Lipsky MS. Content design attributes of antivaccinationweb sites. Journal of the American Medical Association 2002;287(24):3245–8.

17] Chen RT. Vaccine risks: real, perceived and unknown. Vaccine 1999;17:S41–6.18] Smith PJ, Kennedy AM, Wooten K, Gust DA, Pickering LK. Association

between health care providers’ influence on parents who have concernsabout vaccine safety and vaccination coverage. Pediatrics 2006;118:e1287–92.

19] Gust D, Weber D, Weintraub E, Kennedy A, Soud F, Burns A. Physicians who doand do not recommend children get all vaccinations. Journal of Health Com-munication 2008;13:573–82.

20] Glassner B. The culture of fear: why Americans are afraid of the wrong things.New York, NY: Perseus Books Group; 1999.

21] Harris Poll. “Cyberchondriacs” on the rise? Those who go online forhealthcare information continues to increase. Available from: http://www.harrisinteractive.com/vault/HI-Harris-Poll-Cyberchondriacs-2010-08-04.pdf;2010 [cited 4.08.2010].

22] CDC. Percentage of adults aged ≥18 years who looked up health informationon the Internet. Morbidity and Mortality Weekly 2010;59(15):461.

23] Wolfe RM, Sharp LK. Vaccination or immunization? The impact of search termson the Internet. Journal of Health Communication 2005;10(6):537–51.

24] Betsch C, Renkewitz F, Betsch T, Ulshöfer C. The influence of vaccine-critical websites on perceiving vaccination risks. Journal of Health Psychology2010;15(3):446–55.

25] Eysenbach G. How do consumers search for and appraise health informationon the world wide web? Qualitative study using focus groups, usability tests,and in-depth interviews. British Medical Journal 2002;324:573–7.

26] Millenium Project. Available from: http://www.ratbags.com/rsoles/list09.htm;2010 [cited 25.01.2010].

27] Rabia I, Lalitha KS. Understanding the Deep Web. Library Philosophy and Prac-tice 2010:1–5.

28] Leask J-A, Chapman S. An attempt to swindle nature: press anti-immunisationreportage 1993–1997. Australian and New Zealand Journal of Public Health1998;22(1):17–26.

29] Kata A. A postmodern Pandora’s box: anti-vaccination misinformation on theInternet. Vaccine 2010;28:1709–16.

30] Kim P, Eng TR, Deering MJ, Maxfield A. Published criteria for evaluating healthrelated web sites: review. British Medical Journal 1999;318(7184):647–9.

31] Mercola J. How to legally avoid unwanted immunizations of all kinds.Available from: http://newsletters.mercola.com/ReferralProgram/; 2010 [cited7.10.2010].

32] Allen A. Vaccine: the controversial story of medicine’s greatest lifesaver. NewYork, London: W. W. Norton & Company; 2007.

33] Offit PA. Autism’s false prophets: bad science, risky medicine, and the searchfor a cure. New York: Columbia University Press; 2008.

34] Specter M. Denialism: how irrational thinking hinders scientific progress,harms the planet and threatens our lives. New York, NY: Penguin Press; 2009.

35] Wallis C. Debunked. A pivotal paper linking vaccines and autism is retracted.Will the antivaccine movement go on? TIME 2010:18. February 25.

36] Wakefield AJ, Murch SH, Anthony A, Linnell J, Casson DM, Malik M,et al. Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and per-vasive developmental disorder in children. The Lancet 1998;351(9103):637.

1 29 (2

[

[

[

[

[

[

[

[

[

[

880 S.J. Bean / Vaccine

37] Greenfield KT. The autism debate: Who’s afraid of Jenny McCarthy. TIME 2010.February 25.

38] Gregg MA, Brzezny AL, Dawson J, Rietberg K, DeBolt C, Lichangco P, et al. Update:measles—United States January–July 2008. Morbidity and Mortality WeeklyReport 2008;57(33):893–6.

39] Atkinson W, Wolfe C, Hamborsky J, McIntyre L, editors. Epidemiology andprevention of vaccine-preventable diseases. 11th ed. Atlanta, GA: Centers forDisease Control and Prevention, Department of Health and Human Services;2009.

40] Perry RT, Halsey NA. The clinical significance of measles: a review. Journal of

Infectious Diseases 2004;189:S4–16.

41] Ball LK, Evans G, Bostrom A. Risky business: challenges in vaccine risk commu-nication. Pediatrics 1998;101(3):453–8.

42] Gust DA, Kennedy A, Weber D, Evans G, Kong Y, Salmon D. Parents question-ing immunization: evaluation of an intervention. American Journal of HealthBehavior 2009;33(3):287–98.

[

[

[

011) 1874–1880

43] Kahan DM. Fixing the communications failure. Nature 2009;463(21):296–7.

44] Kahan DM, Braman D. Cultural cognition and public policy. Yale Law & PolicyReview 2006;24:149–69.

45] Leask J, Chapman S. ‘The cold hard facts’: immunisation and vaccine pre-ventable diseases in Australia’s newsprint media 1993–1998. Social Science& Medicine 2002;54(3):445–57.

46] Witte K, Allen M. A meta-analysis of fear appeals: implications for effec-tive public health campaigns. Health Education & Behavior 2000;27(5):591–615.

47] Newman TB. The power of stories over statistics. British Medical Journal2003;327(7429):1424–7.

48] Cunningham RM, Bloom JA, Baker CJ. Vaccine-preventable disease: the forgot-ten story. Houston, TX: Texas Children’s Hospital; 2009.

49] NNII. National Network for Immunization Information. Available from:http://www.immunizationinfo.org/about-nnii; 2010 [cited 7.10.2010].