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A taxonomy of reasoning flaws in the anti-vaccine movement
Abstract
In a scholarly analysis of widely held misconceptions, Gilovich provides a classification scheme of common flaws in reasoning seen in contemporary society. He broadly categorizes these flaws as having cognitive determinants or in having motivational and social determinants. In this survey, the authors examine the various claims against routine childhood and adult vaccines as made by the more public and more organized entities of the anti-vaccine movement as well as those made apparent by surveys of parents and other groups of individuals. The claims illustrate the breadth of reasoning flaws while providing a basis for anticipating and correcting them.
... Now consider the healthy cell system, equations (13) and (14). In the case of no cancer cells (NT = PT = 0) equations (13) and (14) reduce to the same forms as (11) and (12), with the exception of the estrogen term. ...
... Now consider the healthy cell system, equations (13) and (14). In the case of no cancer cells (NT = PT = 0) equations (13) and (14) reduce to the same forms as (11) and (12), with the exception of the estrogen term. In this case, the healthy cell system has a trivial equilibrium (NH,PH) = (0,0). ...
... p''it: T ) -l/HNH (2PT+;<P~+KH) -dNH (~)(13) FH(t) l/HNH (2PT+;<P~+KH) + "'/HPH -WHPH (PH::T) -CPH.(14) Hence, the functions iT, iH, gT, gH, dT and dH in the general model are given bydT(NT) = f.l ...
... In explaining the underlying cause, Oraby and Bauch (2015) argue that vaccine acceptance behavior is strongly associated with individuals' cognitive processes and biases, showing that factors such as framing, subjective probability and risk perception impact this behavior. Jacobson et al. (2007) furthermore identified factors underlying such cognitive biases in parents who do not vaccinate their children. ...
... Specifically, these are related to a desire to find order and predictability in random data, difficulty in detecting and correcting errors in reasoning with incomplete and unrepresentative data, eagerness to interpret ambiguous data to fit expectations, as well as self-serving distortions of reality, errors in second-hand information and exaggerated impressions of social support. For example, the lack of direct experience with an infectious disease can lead to the incorrect assumption that such a disease is no longer a threat and that therefore vaccination is unnecessary-which is found to be a common belief among parents with negative vaccine attitudes (Jacobson et al., 2007). Similarly, a study by Asch et al. (1994) showed the tendency toward omission bias to predict negative vaccine attitudes as strongly as beliefs about vaccine harmfulness. ...
... These results imply that parents with negative vaccine attitudes are not less skilled at analytical reasoning about scientific facts and evidence regarding vaccination, which resonates with the notion that parental education does not directly determine vaccine attitudes (Gowda & Dempsey, 2013). On the other hand, we found parents with more negative beliefs and ATV to be less skilled in overriding omission bias, which is also in line with different previous findings (Jacobson et al., 2007). We suggest that negative attitudes toward vaccination emerge a result of domain-specific reasoning errors as measured by the omission bias, and not because of intuitive, fast and unadvised reasoning which cognitive reflection would be able to correct. ...
Although previous studies have demonstrated an association between vaccine attitudes and cognitive biases, often resulting in vaccination hesitancy, the exact contribution of rationality has not been fully clarified. We tested two hypotheses regarding the impact of rationality on vaccine attitudes stemming from bounded and expressive rationality. We focused on parental vaccine attitudes operationalized by the affective, behavioral, and cognitive attitude components and investigated how these are influenced by disillusionment toward authorities and ability to engage in rational thinking operationalized using cognitive reflection and heuristics and biases tasks. The study was of a cross‐sectional correlational design with a non‐probabilistic sample of 823 volunteer participants surveyed online in April and May 2018 in Croatia. The results identified disillusionment toward authorities as a predictor of all components. Furthermore, performance on heuristics and biases tasks also predicted the affective and cognitive, but not the behavioral component, whereas cognitive reflection had no impact on vaccine attitudes. Next, a moderation effect of disillusionment toward authorities on the association between the omission bias task and all attitude components was identified. Parents with low disillusionment demonstrated positive vaccine attitudes regardless of their rationality, whereas for parents with high disillusionment a significant positive correlation between performance on the omission bias task as assessed with a vaccination vignette and attitudes was identified. This suggests that the ability to resist vaccine specific omission bias, that is, higher rationality, can decrease the negative effects of disillusionment, which supports the bounded rationality hypothesis.
... Alarmingly, such beliefs might impact public safety since they may negatively affect vaccination rates (54,55). Another line of research demonstrated that decision-making processes of vaccine-hesitant parents are associated with reasoning biases and errors (56), especially omission bias (57), and that hesitant parents often refer to various emotional cues, anecdotal stories, and vivid experiences of peers (8,58). These findings may be interpreted in line with the hypothesis that people, during their evolutionary history, developed a higher sensitivity to one kind of threats and a lesser sensitivity to other kinds (29). ...
... The results moreover demonstrate that parents with more negative beliefs and unpleasant emotions toward vaccination are less skilled in overriding heuristic thinking, and therefore more prone to reasoning biases, which is also in line with different previous findings (56). In interpreting these results, several limitations should be kept in mind. ...
Introduction: Previous research suggests that decision-making processes related to System 1 and 2 and deviations from rationality can significantly impact individuals’ behavior and important life outcomes, including health-related ones. These may be particularly significant in the emotionally burdened context of child vaccination, which may trigger further deviations from rational thinking. Still, it is not fully understood how different cognitive and emotional factors related to these cognitive systems interact, and only a small portion of studies has focused on researching these constructs in the context of health.
Objectives: The aim of this thesis was to address the role of cognitive (cognitive reflection, heuristic thinking, need for cognition, faith in intuition, maximization) and emotional factors (dispositional optimism vs. pessimism, emotions toward vaccination) in the context of other well-known factors (trust in and satisfaction with health provider, trust toward authorities) which contribute to health-decision-making and behavior. The latter included general health decision-making (leading a healthy everyday lifestyle, engagement in healthy behaviors, and medical adherence), as well as the parental decision on child vaccination (vaccine conspiracy beliefs, uptake, and vaccine attitudes in the affective, cognitive and behavioral component). Special focus was also put on vaccine-hesitant parents’ reasoning and hypothetical situations in which they would reconsider vaccinating and describing different strategies by which they avoid mandatory vaccination.
Methods: This thesis consisted of three studies. The first was a cross-sectional correlational study with a non-probabilistic sample of 186 volunteer student participants. The second was a cross-sectional correlational study with a non-probabilistic sample of 823 volunteer parents surveyed online. The third, qualitative study included semi-structured interviews conducted with 25 vaccine-hesitant parents recruited through a mixed purposeful sampling strategy.
Results: The results of the first study showed that leading a healthy everyday lifestyle was predicted by maximizing, which also predicted engagement in health-promoting activities. Such engagement was also predicted by optimism and the ability to override heuristic and biased thinking, while a higher need for cognition and trust in healthcare predicted adherence to medical advice. The results of the second study showed vaccine conspiracy beliefs were associated with stronger unpleasant emotions toward vaccination, intuitive-experiential thinking, and lower education, while unpleasant emotions toward vaccination and intuitive thinking were associated with a lesser vaccine uptake. Next, disillusionment with authorities predicted all vaccine attitude components, performance on heuristic and biases tasks predicted the affective and cognitive but not the behavioral component, whereas cognitive reflection had no impact on vaccine attitudes. Finally, a moderation effect of disillusionment on the association between heuristic and biases tasks and the cognitive and behavioral attitude components was identified. Parents with low disillusionment demonstrated positive vaccine attitudes regardless of their rationality, whereas for parents with high disillusionment a significant positive correlation between performance on heuristics tasks and attitudes was identified, indicating rationality can decrease the negative effects of disillusionment. The results of the third study indicated that decision-making on child vaccination is complex and associated with different interrelated factors, especially the intuitive-experiential cognitive style, as well as supported the social intuitionist model of moral reasoning. Also, it indicated that parents adopt different strategies of avoiding mandatory vaccination and differ in their determination and potential to reconsider their decision, as well as hypothetical situations in which they might do so.
Conclusion: These results provide novel insights on the importance of cognitive and emotional factors in health decision-making. It is demonstrated that vaccine hesitancy is linked to the functioning of the intuitive-experiential cognitive style and that rationality can contribute to health-supporting behaviors in a beneficial manner.
... The rise of specific vaccine conspiracy beliefs is not surprising because vaccine hesitant beliefs and conspiracy theories in general share several common elements. First, both vaccine hesitancy and general conspiracy beliefs tend to reduce the complexity of reality, which includes mistrust of scientific research, rejection of science, or acceptance of alternative explanations of scientific data (Bessi et al., 2015;Jacobson, Targonski, & Poland, 2007), creating a climate of disengagement of mainstream beliefs and officially recommended practices. Recent studies have shown such negative attitudes towards science to be associated with ideological right orientation (Gauchat, 2012;Motta, Callaghan, & Sylvester, 2018). ...
... Related to these notions, the third similarity between vaccine hesitancy and general conspiracy beliefs is that both seem to be related to different aspects of intuitive and experiential decision-making that is, within dual-processing reasoning theories, associated with the so-called System 1 reasoning and proneness to various heuristics and biases (Brotherton & French, 2014;Jacobson et al., 2007;Leman & Cinnirella, 2007). Also, personal experience and anecdotal information affects peoples' general decision-making and reasoning, especially when presented in a salient and vivid fashion (Ubel, Jepson, & Baron, 2001). ...
Objective: Vaccine hesitancy has been identified as one of the major contributors to child under-vaccination. Research indicates that some hesitant parents’ mistrust extends to specific conspiracy ideation, but research on vaccine conspiracy beliefs is still scarce. Our objective was to explore factors contributing to parental vaccine conspiracy beliefs and actual vaccine uptake in children.
Design: A cross-sectional correlational design with a non-probabilistic sample of 823 volunteer participants surveyed online.
Main outcome measures: We focussed on the contributions of the analytically rational and experientially intuitive thinking styles, as well as measures of emotional functioning, namely optimism and emotions towards vaccination, to vaccine conspiracy beliefs and vaccine uptake as outcomes.
Results: The obtained results showed that greater vaccine conspiracy beliefs were associated with stronger unpleasant emotions towards vaccination and greater experientially intuitive thinking, as well as lower levels of education. Furthermore, unpleasant emotions towards vaccination and intuitive thinking were associated with vaccine refusal.
Conclusion: These findings confirm the primary importance of emotions, along with the propensity towards intuitive thinking, in the context of vaccine conspiracy beliefs and refusal, supporting the notion that parents’ avoidance is guided by their affect. These results have direct implications for addressing vaccine hesitancy within public campaigns and policies.
... First, it is important to note that, despite trying to mimic the science, the anti-vaccination movements rely mostly on rhetorical arguments [122,123]. In many ways, anti-vaccinationism can be seen as part of a larger phenomenon of 'denialism' or 'the employment of rhetorical arguments to give the appearance of legitimate debate where there is none, an approach that has the ultimate goal of rejecting a proposition on which a scientific Box 2. The Boycott of polio vaccination. ...
... This is known as the 'omission bias' [126]. Another important bias that could be triggered by anti-vaccination activists is the 'co-incidence dragon' or the propensity to attribute every event occurring after immunization to be caused by vaccination, such as the false association between vaccination and sudden infant death syndrome (because of the timing of childhood vaccination both events have high probability to occur subsequently) [123,127]. Viewing anti-vaccination content could also influence parents to consider vaccines as risky because of the 'availability bias' or the propensity to judge something as frequent if it is easily recalled. For instance, a recent study looking at the potential impact of conspiracy theories on vaccination intentions has highlighted that exposure to anti-vaccine conspiracy theory (pharmaceutical companies manipulated research data on vaccine efficacy to make profits) was associated with reduced parental vaccination intentions [128]. ...
Despite being recognized as one of the most successful public health measures, vaccination is perceived as unsafe and unnecessary by a growing number of parents. Anti-vaccination movements have been implicated in lowered vaccine acceptance rates and in the increase in vaccine-preventable disease outbreaks and epidemics. In this review, we will look at determinants of parental decision-making about vaccination and provide an overview of the history of anti-vaccination movements and its clinical impact.
... A number of these studies created taxonomies or tried to identify specific features of the misunderstandings that these sites were thought to perpetuate. The article that best exemplifies this tendency is Jacobson et al [22], the title of which is indicative of the approach: "A Taxonomy of Reasoning Flaws in the Anti-Vaccine Movement." During this period, 2 studies about vaccination influenced by the Pandora's box metaphor appeared in the pages of medical journals [23,24]. ...
... One study notes that antivaccine movements are well versed in multimedia communication because the groups often are led by spokespersons who use a variety of media (eg, books, television appearances) to build their ethos (credibility) as whistleblowers [27]. Although researchers have created sophisticated taxonomies of static websites [22,28,29], the strategies they offer to counter vaccine-skeptical discourses either have not been adopted by provaccine websites or have not been effective in general. For instance, one strategy offered is mass education campaigns that share images and personal narratives of people affected by vaccine-preventable diseases, such as pertussis [28]. ...
Background:
Current concerns about vaccination resistance often cite the Internet as a source of vaccine controversy. Most academic studies of vaccine resistance online use quantitative methods to describe misinformation on vaccine-skeptical websites. Findings from these studies are useful for categorizing the generic features of these websites, but they do not provide insights into why these websites successfully persuade their viewers. To date, there have been few attempts to understand, qualitatively, the persuasive features of provaccine or vaccine-skeptical websites.
Objective:
The purpose of this research was to examine the persuasive features of provaccine and vaccine-skeptical websites. The qualitative analysis was conducted to generate hypotheses concerning what features of these websites are persuasive to people seeking information about vaccination and vaccine-related practices.
Methods:
This study employed a fully qualitative case study methodology that used the anthropological method of thick description to detail and carefully review the rhetorical features of 1 provaccine government website, 1 provaccine hospital website, 1 vaccine-skeptical information website focused on general vaccine safety, and 1 vaccine-skeptical website focused on a specific vaccine. The data gathered were organized into 5 domains: website ownership, visual and textual content, user experience, hyperlinking, and social interactivity.
Results:
The study found that the 2 provaccine websites analyzed functioned as encyclopedias of vaccine information. Both of the websites had relatively small digital ecologies because they only linked to government websites or websites that endorsed vaccination and evidence-based medicine. Neither of these websites offered visitors interactive features or made extensive use of the affordances of Web 2.0. The study also found that the 2 vaccine-skeptical websites had larger digital ecologies because they linked to a variety of vaccine-related websites, including government websites. They leveraged the affordances of Web 2.0 with their interactive features and digital media.
Conclusions:
By employing a rhetorical framework, this study found that the provaccine websites analyzed concentrate on the accurate transmission of evidence-based scientific research about vaccines and government-endorsed vaccination-related practices, whereas the vaccine-skeptical websites focus on creating communities of people affected by vaccines and vaccine-related practices. From this personal framework, these websites then challenge the information presented in scientific literature and government documents. At the same time, the vaccine-skeptical websites in this study are repositories of vaccine information and vaccination-related resources. Future studies on vaccination and the Internet should take into consideration the rhetorical features of provaccine and vaccine-skeptical websites and further investigate the influence of Web 2.0 community-building features on people seeking information about vaccine-related practices.
... По-видимому, наиболее перспективными в плане проведения соответствующих научных изысканий являются концепции: • «модели здоровья», проясняющей вопрос того, какие установки в отношении собственного здоровья способны изменить саногенное, т. е. направленное в сторону сохранения и развития здоровья (здоровьесберегающее), поведение человека; • деструктивных социальных эпидемий, объясняющей механизмы проникновения «заразных» идей и дезадаптивных форм поведения в сознание и стереотипную поведенческую активность человека и акцентирующей особое внимание на масштабах, способах, формах и аффектогенных приемах подачи мотивирующей информации [12]; • социально-ориентированного рынка здоровья, обращающей внимание на необходимость достаточно жесткого нормативного регулирования поведения субъектов этого рынка, оказывающих влияние на саногенное поведение населения. В таком аспекте проблема эффективного противодействия антивакцинальному лобби еще не исследовалась [13,14]. В то же время результаты такого научного поиска могут значительно превосходить масштабы поставленной прагматической задачи и оказывать существенное влияние на формирование цивилизованного рынка здоровья. ...
... Данный факт, по нашему мнению, также остается без должной интерпретации. Например, в аспекте того, что подача заведомо искаженной информации от врачебного персонала могла быть обусловлена вовлечением этих специалистов в «разгоняемую» социальную эпидемию антивакцинального поведения, а также экономическими причинами [9,12,13]. ...
The problem of preventing the distribution of infectious diseases, due to the need to find new, more effective strategies of counteraction to the antivaccine lobby, is considered. The necessity of complex studies on the testing of main hypothetical theses of such strategy is grounded. The main blocks of the corresponding research project are considered. The conclusion about the need to identify interrelations between certain types of biological and social epidemics is drawn, influencing on which, it is possible to achieve impressive results in the effective prevention of these socially dangerous phenomena.
... Researchers have compiled several inventories of flawed argumentation that are used to disinform, for example by populist politicians (Blassnig et al., 2019), anti-vaccination activists (Jacobson et al., 2007), or by people who spread conspiracy theories . The underlying rationale for those inventories is that, by and large, human cognition is a truth-tracking device. ...
... The primer provided explanations and rebuttals to anticipated arguments by anti-vaccine activists. This enabled the media to understand and defang those contrarian arguments (Jacobson et al., 2007). In arguably the largest real-world inoculation experiment to date, Twitter recently forewarned all of its U.S. users about false information concerning voting by mail that they may encounter during the 2020 U.S. Presidential election (Ingram, 20202020). ...
There has been increasing concern with the growing infusion of misinformation, or “fake news”, into public discourse and politics in many western democracies. Our article first briefly reviews the current state of the literature on conventional countermeasures to misinformation. We then explore proactive measures to prevent misinformation from finding traction in the first place that is based on the psychological theory of “inoculation”. Inoculation rests on the idea that if people are forewarned that they might be misinformed and are exposed to weakened examples of the ways in which they might be misled, they will become more immune to misinformation. We review a number of techniques that can boost people’s resilience to misinformation, ranging from general warnings to more specific instructions about misleading (rhetorical) techniques. We show that based on the available evidence, inoculation appears to be a promising avenue to help protect people from misinformation and “fake news”.
... The issue of the vaccine's safety was one aspect of this general controversy which emerged even before vaccination began in late October 2009 and involved a much smaller number of actors. In this study, I will focus on this subcontroversy, and the more limited sub-set of actors who were involved in it by opposing public health authorities, since safety is the subject most often associated with "the Antivaccine Movement" (Jacobson et al., 2007;Kata, 2010;Poland and Jacobson, 2011;. Also, the failure of this vaccination campaign, with only 7.9% of the population being vaccinated, was found to be linked to the diffusion of vaccine-critical information (Raude et al., 2010). ...
... Indeed, they all explicitly evoked the dangers of "vaccines", "vaccination" or "vaccinations" in general. Each of these five actors presented at least one of the typical arguments identified in the academic literature as "antivaccinationist" (Hobson-West, 2003;Jacobson et al., 2007;Kata, 2010;J. A. Leask and Chapman, 1998;, and more often combined several of them. ...
In this article I discuss the definition of “the Antivaccine Movement” using the case of the French controversy over the safety of the 2009 pandemic flu vaccine. I show that the group of main actors who criticized the vaccine's safety is heterogeneous. This heterogeneity can be found in the type of arguments mobilized to question the vaccine's safety and in these actors' likelihood of being involved in any vaccine-related controversies. I show that only a minority of these actors rejected vaccination in general and mobilized against all vaccination campaigns. Most of these actors only occasionally mobilized against a given vaccine or vaccination campaign and they did so to promote a political or cultural agenda that went beyond the vaccine itself. Using these results, I argue that in order to better understand how vaccine-related controversies emerge and why some activists devote time and resources to spread vaccine-critical arguments, social scientists should use three distinct concepts to refer to vaccine criticism: The Antivaccine Movement, the Marginally Antivaccine Movements and the Occasionally Vaccine Critical Movements. To do so would enable social scientists and public health experts to better understand the different ways in which vaccination can become politicized and how this politicization evolves.
... Ancak, yanlış anlaşılan aşı komplikasyonları, aşıya bağlı yan etkilerin varlığı nedeniyle farklı görüşlere sahip bazı gruplar toplumda aşı karşıtlığına neden olabilmektedir. Hatta bu bireyler kendi çocuklarının rutin aşılarını yaptırmama ya da geciktirme eğilimi göstererek çocuklarını ciddi risk altında bırakabilmektedirler (3). Aşıların, enfeksiyon etkenlerinin kontrol altına alınmasındaki önemli araçlardan biri olması nedeniyle aşı karşıtı grupların (anti-vaccine groups) artması toplumsal bağışıklık (herd immunite) anlamında ileride küresel bir sorun olacaktır (1). ...
... En realidad sigue vigente, y en la actualidad perviven comunidades pertenecientes a la minoría protestante ortodoxa (2% de la población) que no se vacunan, ocupando el autodenominado Bible belt 13 en Países Bajos. Con diferencias en cuanto a credo, pero con idénticas consecuencias, este fenómeno se reproduce en Alemania.En Suecia, en concreto en Estocolmo existió un grupo anti-vacunas que hizo disminuir hasta un 40% el porcentaje de vacunados en 1872[32]. En la actualidad los 11 (En España ocurrió algo similar al promover la vacunación en los hospitales, a los que la población en general prefería no acudir.[33] ...
Introducción: En los últimos tiempos se ha detectado una disminución en la
cobertura vacunal contra el sarampión, vacuna triple vírica, por parte de los
servicios de salud pública. Paralelamente, España ha registrado numerosos brotes
de sarampión desde el 2010. Algunos expertos relacionan la disminución en la
inmunización preventiva con los mensajes de grupos contrarios a la vacunación
que desarrollan su actividad en Internet.
Objetivos: Analizar los contenidos críticos u opuestos a la vacuna triple vírica y
afirmaciones acerca del sarampión, accesibles en sitios de Internet en castellano y
catalán en mayo-junio de 2012. Realizar una caracterización de los sitios y
conocer su difusión en las redes sociales, así como establecer la probabilidad de
encontrar sitios con contenidos contrarios a la vacunación mediante una búsqueda
sencilla en Google® y Bing®.
Métodos: Estudio descriptivo transversal. Búsqueda de sitios en Internet
mediante los buscadores Google® y Bing® con las palabras clave seleccionadas
en castellano: “vacuna”, “vacunas”, “vacunación”, “sarampión”, “vacuna triple
vírica”, “inmunidad” e “inmunización” y sus equivalentes en catalán. Se revisaron
1.100 resultados de búsqueda en total, 800 en castellano y 300 en catalán, que
cumplieran con los criterios buscados. Se empleó el análisis del contenido como
instrumento para reconocer los argumentos más frecuentes en contra de la vacuna
triple vírica presentes en los sitios a estudio, así como las aseveraciones vertidas
acerca del sarampión.
Resultados: Se analizaron quince sitios con argumentos críticos con la
vacunación, trece en castellano y dos en catalán. La mayoría de los sitios (80%)
contenían mensajes en contra de la vacuna, así como consideraron al sarampión
como un proceso leve. La mayoría de los sitios empleaban herramientas web 2.0
y la mitad extendían su actividad a las redes sociales, principalmente Facebook y
Twitter. La probabilidad de encontrar un sitio con contenido crítico con la
vacunación en Internet, en una búsqueda común en castellano, en Google® y
Bing®, entre los diez primeros resultados fue de un 10%.
Conclusiones: El sarampión fue considerado un proceso leve, propio de la
infancia, que había disminuido antes de la introducción de la vacuna gracias a las
mejoras en las condiciones higiénico-sanitarias. Los argumentos críticos o
contrarios a la triple vírica en los sitios a estudio incluyeron aspectos acerca de la
seguridad y efectividad de la vacuna, cuestionando su inmunogenicidad y
destacando sus efectos adversos. Alusiones al estudio de Wakefield como válido.
Se apeló frecuentemente al derecho de los padres a las decisiones informadas.
Críticas contra los organismos pro-vacunistas y las empresas farmacéuticas.
Negación de la inmunidad de grupo.
... Jenny McCarthy, celebrity founder of Generation Rescue, an antivaccination group, encourages fellow "Mother Warriors" of children with autism to "[follow] her intuition even when people tell her she is crazy" (McCarthy, 2012). Medical professionals have declared antivaccinationists to be irrational and prone to conspiratorial thinking (Jacobson, Targonski, & Poland, 2007). ...
Today, the majority of American adults uses the internet and looks for health information online. Of interest in this dissertation are people who do not subscribe to mainstream views of health, and may use the internet to discover, bolster, or share their alternative views. Although the Centers for Disease Control and Prevention (CDC) have named fluoridated drinking water and vaccination as two of the top ten public health achievements of the 20th century, there is a significant minority of people who has concerns about the safety and effectiveness of these practices.
There are two essential purposes for this dissertation. First, it describes the nature of internet use among people who hold nonmainstream views of health issues. Second, it tests the hypotheses that the extent of people's internet use is a reflection of two classes of influence: 1) individual traits, such as demographic characteristics, feelings of estrangement, and need for cognition, and 2) their inability to find support from other sources, specifically mainstream media and their face-to-face social network. These analyses are informed by three sets of data: interviews with people who have varying views on fluoridation, a pair of nationally representative surveys (one on the MMR vaccine, and one on fluoridated water), and a corresponding pair of purposive surveys.
The interview results identified important themes and issues surrounding nonmainstream health beliefs, especially their connection to personal experience and perceived credibility of information sources. The representative surveys found that approximately 10% of Americans believe that the MMR vaccine and fluoridated water are unsafe, with the rest of the population about evenly divided between being uncertain and believing that the health measures are safe. Notably, believing that these measures were unsafe was unrelated to any demographic characteristics, but internet use on those topics was strongly related. Internet use on those topics was associated with youth and college education, as well as perceiving the news media as having a different view from their own. The lack of social network support for one's views on these topics, however, was unrelated to internet use. The implications of these findings and future research directions are discussed.
... Distrust of vaccines has seen a recent increase, resulting in jumps in the incidences of diseases that had long been defeated by modern medicine (Gangarosa et al., 1998). This distrust is justified with poor reasoning (Jacobson et al., 2007). Per the naturalistic fallacy, among the reasons for the distrust for vaccines is that they are not "natural" (Offit, 2011: 116-117;Poland and Jacobson, 2001). ...
Bryan Caplan’s The Myth of the Rational Voter popularizes the “near-neoclassical” demand curve for irrationality. This article attempts to show that there is a demand for irrationality at prices higher than zero. This may change policy implications. Many instances of consumer behavior, such as paying a premium for locally produced and “fair trade” goods, the use of local currencies, and the failure to vaccinate children, are other instances of the means-ends irrationality that Caplan observes in political markets.
... In addition, misinformation about viruses and vaccines is rampant. This false information is persistent, widely spread (Jacobson et al. 2007), and increasingly hard to counter as more people get their health information from the internet. Indeed, the Joint Committee on National Health Education Standards (2007) recognized the need to educate the public about virology and infectious disease as a high national priority. ...
Current research in virology is changing public conceptions about vaccines and infectious disease. The University of Nebraska State Museum collaborated with research virologists, science writers, artists and learning researchers to create public outreach materials about viruses and infectious disease. The project, funded by the National Institute of Health's SEPA program, developed comics, a book with Carl Zimmer, and other materials and programs. The project launched three kinds of learning research: 1) a survey of Nebraska adults on their opinions about vaccines and infectious disease; 2) a study comparing the mental models of viruses, vaccines, and infection from virologists, teachers, and students; and 3) a controlled study of 873 high school students randomly assigned to read either a comic or a text-based essay with the same virus information.
... Conspiratorial thinking is endemic in anti-vaccination groups, with those advocating the scientific and medical consensus often regarded as agents of some ominous interest group bent on concealing "the truth". This becomes a defence mechanism to protect beliefs that are incompatible with the evidence, and unsurprisingly perhaps proponents of such views display not only conspiratorial traits but a litany of reasoning flaws, a reliance on anecdote over data and low cognitive complexity in thinking patterns [5]. ...
Conspiratorial ideation is the tendency of individuals to believe that events and power relations are secretly manipulated by certain clandestine groups and organisations. Many of these ostensibly explanatory conjectures are non-falsifiable, lacking in evidence or demonstrably false, yet public acceptance remains high. Efforts to convince the general public of the validity of medical and scientific findings can be hampered by such narratives, which can create the impression of doubt or disagreement in areas where the science is well established. Conversely, historical examples of exposed conspiracies do exist and it may be difficult for people to differentiate between reasonable and dubious assertions. In this work, we establish a simple mathematical model for conspiracies involving multiple actors with time, which yields failure probability for any given conspiracy. Parameters for the model are estimated from literature examples of known scandals, and the factors influencing conspiracy success and failure are explored. The model is also used to estimate the likelihood of claims from some commonly-held conspiratorial beliefs; these are namely that the moon-landings were faked, climate-change is a hoax, vaccination is dangerous and that a cure for cancer is being suppressed by vested interests. Simulations of these claims predict that intrinsic failure would be imminent even with the most generous estimates for the secret-keeping ability of active participants—the results of this model suggest that large conspiracies (≥1000 agents) quickly become untenable and prone to failure. The theory presented here might be useful in counteracting the potentially deleterious consequences of bogus and anti-science narratives, and examining the hypothetical conditions under which sustainable conspiracy might be possible.
... Anti-vaccine sentiment tends to demonstrate numerous reasoning flaws, particularly reliance on anecdote over data. 56 Conspiratorial narratives around vaccines spread quickly and have detrimental effects on public intention to vaccinate. 57 Unsubstantiated claims of harm appearing in media and from local political figures are especially potent in driving vaccine opposition; in Japan, HPV vaccination recommendations were suspended after claims of adverse reactions appeared in local media in 2013. ...
Human papillomavirus (HPV) is a common sexually transmitted infection. There is a well-established link between HPV and the development of cervical cancer, but HPV infection is also associated with vaginal and vulvar cancer, head and neck cancers as well as anal cancers in both sexes and penile cancer in men. Despite this, since its introduction in 2008, the United Kingdom has included only girls in its vaccination programme and, in 2017, suggested that it was not cost effective to extend the vaccine to adolescent boys. Men-who-have-sex-with-men (MSM) have been offered the HPV vaccine in the United Kingdom since 2016. A number of countries (21 to date) have implemented a universal HPV vaccination programme, with many countries arguing that female-only vaccination programmes protect males via herd immunity and that MSM will be protected via targeted vaccination programmes, although these may be limited in their effectiveness. Following an advocacy campaign to extend the HPV vaccination programme to boys in the United Kingdom, in July 2018 the Joint Commission for Vaccination and Immunisation recommended that boys should be included alongside 12/13-year-old girls in a school-based programme. Given that this decision has been delayed by many years, it is imperative that the UK Government and Department of Health implement this vaccine programme as quickly as possible and by September 2019 at the latest, that a catch-up programme for boys is introduced and, given the feminisation of HPV, that information materials on HPV vaccination that are targeted at boys, their parents and teachers are made widely available.
... Gilovich (1991) sorted reasoning flaws into two main categories-cognitive (resulting from the tendency to find order in random data) and motivational/social (wishful thinking or self-serving distortions of reality). This taxonomy has been applied, for example, to the most common antivaccine myths (Jacobson, Targonski, & Poland, 2007). In another domain, Rahmstorf (2004) categorized climate skepticism into three types: trend (climate change is not happening), attribution (climate change is not caused by humans), and impact (impacts from climate change are inconsequential). ...
The increasing prevalence of misinformation in society may adversely affect
democratic decision making, which depends on a well-informed public. False information
can originate from a number of sources including rumors, literary fiction,
mainstream media, corporate-vested interests, governments, and nongovernmental
organizations. The rise of the Internet and user-driven content has provided a venue
for quick and broad dissemination of information, not all of which is accurate. Consequently,
a large body of research spanning a number of disciplines has sought to
understandmisinformation and determine which interventions are most effective in
reducing its influence. This essay summarizes research into misinformation, bringing
together studies from psychology, political science, education, and computer science.
Cognitive psychology investigates why individuals struggle with correcting
misinformation and inaccurate beliefs, and why myths are so difficult to dislodge.
Two important findings involve (i) various “backfire effects,” which arise when
refutations ironically reinforce misconceptions, and (ii) the role of worldviews
in accentuating the persistence of misinformation. Computer scientists simulate
the spread of misinformation through social networks and develop algorithms
to automatically detect or neutralize myths. We draw together various research
threads to provide guidelines on how to effectively refute misconceptions without
risking backfire effects.
... This is compounded by sensational news stories about outbreaks that rarely provide a larger context that can help promote a basic understanding of how viruses affect people and the environment. The alarming patterns in misinformation, particularly among antivaccine advocates (Jacobson et al. 2007), suggest the need for more robust educational programs. Indeed, the need to educate youth about viruses and infectious disease in a meaningful and relevant way is a high national priority (Joint Committee on National Health Education Standards 2007). ...
Graphic novels or comics are powerful tools to motivate youth to become interested in science. Embedding science concepts into a story with graphics that appeal to teen culture makes abstract content approachable, stimulates youth interest, and promotes learning. This presentation will discuss the goals of the NIH-funded World of Viruses and Biology of Human comic series and the research results that supports using these approaches.
... 6 Additionally, a Canadian study suggested that the odds of parents perceiving vaccines as unsafe rose considerably for those who searched for vaccine safety information on the internet. 7 Herein lies the problem: From the skeptical point of view, these websites present valid questions. From our point of view they are absurd and dangerous, but providing evidence for an absence of risk is painfully difficult. ...
There are many things that, as physicians, we universally take for granted. One does not need a background in medical statistics to understand that seat belts save lives and reduce injuries in car accidents. Nor do you need to have an epidemiology degree to know that tobacco smoking is causative for lung cancer. At some point in your undergraduate classes, you almost certainly heard the story of Edward Jenner, the milkmaids, and the resulting smallpox vaccine. Thanks to Dr. Jonas Salk, a true hero of the 20th Century, the last U.S. polio case was in 1979.1 The benefits of vaccination clearly outweigh the risks. Therefore measles, mumps, rubella and diphtheria should be nearly unknown today … right?
... Decisions regarding childhood vaccines are often insufficiently informed (Lehmann et al., 2017) and deliberations on the decision against vaccines demonstrably suffer from a variety of reasoning flaws (Jacobson et al., 2007). An explanation is that these decisions rely on the assessment of risk (Brewer et al., 2007)-both the risk of obtaining a vaccine preventable disease and the risk of obtaining vaccine side effects. ...
Online vaccine-critical sentiments are often expressed in appealing personal narratives, whereas vaccine-supporting information is often presented in a non-narrative, expository mode describing scientific facts. In two experiments, we empirically test whether and how these different formats impact the way in which readers process and retrieve information about childhood vaccination, and how this may impact their perceptions regarding vaccination. We assess two psychological mechanisms that are hypothesized to underlie the persuasive nature of vaccination narratives: the availability heuristic (experiment 1, N = 418) and cognitive resistance (experiment 2, N = 403). The results of experiment 1 showed no empirical evidence for the availability heuristic, but exploratory analyses did indicate that an anti-vaccination narrative (vs. expository) might reduce cognitive resistance, decrease vaccination attitudes and reduce attitude certainty in a generally pro-vaccination sample, especially for those who were more vaccine hesitant. Preregistered experiment 2 formally tested this and showed that not narrative format, but prior vaccine hesitancy predicts cognitive resistance and post-reading attitudes. Hesitant participants showed less resistance toward an anti-vaccine text than vaccine-supporting participants, as well as less positive post-reading attitudes and attitude certainty. These findings demonstrate belief consistency effects rather than narrative persuasion, which has implications for scientific research as well as public health policy.
... Related to this, Law (2011) explains various ways that lead educated and intelligent people to develop beliefs which are opposed to rationality or science. His examples resonate with research repeatedly showing reasoning in vaccine hesitancy to be burdened with various reasoning flaws (Jacobson, Targonski, & Poland, 2007). The idea that attitudes towards vaccines are based in intuition has been proposed before. ...
Despite extensive research evidencing child vaccination is safe and effective, we are witnessing a trend of increasing vaccine hesitancy which is listed among the top ten global health threats. Although some countries incorporate mandatory vaccination programs, no particularly efficient strategies for addressing vaccine avoidance have so far been identified. Within this study we investigated perceptions and reasoning of vaccine hesitant parents from Croatia where child vaccination is mandatory. The aims were to reveal different strategies by which they avoid mandatory vaccination schedules and hypothetical situations in which they would reconsider vaccinating, as well as to identify features of related decision-making. We conducted 25 semi-structured interviews with vaccine hesitant parents and analyzed the data using the framework of thematic analyses. The identified themes were related to the parents’ decision-making process, reflection as well as justification of their decision, avoidance behavior of mandatory vaccination schedules and related consequences, dealing with outcomes of the decision and reconsidering vaccinating. The results support and extend previous findings regarding vaccine reasoning, linking hesitancy with the experientially intuitive thinking style and social intuitionist model of moral reasoning. The findings provide important insights into vaccination avoidance and potential for reconsideration, as well as dealing with related risks. Furthermore, we offer a general framework as well as practical guidelines that may help the development of strategies aimed at increasing vaccination rates.
Keywords: vaccine hesitancy, vaccine decision-making, avoiding vaccination, moral foundations theory, experientially intuitive thinking style
... 13. Voir notamment, pour le cas français, P. et al., 1994 ;Browne, 2018 ;Horne et al., 2015 ;Jacobson et al., 2007 ;Meszaros et al., 1996 ;Miton et Mercier, 2015 ;Motta et al., 2018 ;Schmid et Betsch, 2019) : -Le biais d'omission : nous craignons davantage les conséquences négatives d'une action (se faire vacciner ou vacciner son enfant) plutôt que les conséquences de l'abstention, de sorte que les risques des vaccins seraient surestimés par rapport aux risques de la maladie correspondante. ...
En France comme ailleurs, les autorités de santé sont aujourd’hui confrontées à une défiance inédite des populations à l’égard de la vaccination. Pour appréhender ce phénomène, les chercheurs et les experts de santé publique ont encore largement recours à l’approche traditionnelle du Public Understanding of Science (pus). Cette approche défend un modèle déficitaire qui souligne les lacunes des profanes, qui seraient insuffisamment éduqués ; elle souligne aussi les multiples biais cognitifs qui affecteraient leurs perceptions ; enfin, elle diagnostique la montée d’un mouvement antiscience. Cet article dresse un état des lieux des connaissances relatives aux attitudes vis-à-vis des vaccins disponibles en France, en saisissant ce cas pour mettre la pus à l’épreuve. Il montre que la limite principale de cette approche réside dans son incapacité à intégrer la dimension sociale et culturelle de la cognition. Il esquisse, enfin, un modèle alternatif au pus qui place en son cœur la dimension culturelle de toute cognition et permet d’articuler les attitudes des individus avec l’émergence des controverses et les structures sociales.
... This too likely contributed to vaccine hesitancy during the third and the fourth phase of the vaccination drive. Researchers have termed this phenomenon as "Co-incidence dragon" [Post hoc ergo propter hoc: after this, therefore because of this] which is the cognitive flaw in reasoning that stems from natural human desire to find order and predictability in random data (Jacobson et al., 2007;MacDonald et al., 2012). ...
Vaccine hesitancy is context specific and varies over time and space. Therefore, strategies to tackle vaccine hesitancy based on evidence from high income countries are unlikely to serve the purpose adequately in LMICs. We use district level evidence on COVID-19 vaccine uptake rates from an LMIC - India to provide evidence of COVID-19 vaccine hesitancy. We argue that vaccination rates during the different phases of COVID-19 vaccination across the districts is likely to be related to vaccine hesitancy. Districts with larger rural population and lower literacy rates had lower vaccination rates. High past child immunization rates were positively correlated with COVID-19 vaccination uptake. Across the four phases of vaccination drive, vaccine hesitancy was the highest during the third phase of the vaccination drive, and therefore the above correlations were strongest during the third and the fourth phase. Measures of family planning indicators too seem to be correlated with vaccine uptakes during the third phase which indicate the regions most susceptible to vaccine hesitancy.
... Although little literature investigates this specific association in cases of vaccine hesitancy, with remarkable exceptions (see Anderson, 2016;Schindler et al., 2020;Tomljenovic et al., 2019Tomljenovic et al., , 2020, research shows that, under incomplete information, individuals might stumble across heuristic cognitive flaws that support vaccine misconceptions (Jacobson, 2007). Poland et al.'s (2014) review found that heuristics use is associated with automatic processing and greater vaccine skepticism. ...
Rationale
In this study, we consider cognitive differences in vaccine hesitancy and how perceived risks intervene in this relationship. Recent research agrees on the existence of two cognitive processes, intuitive and analytic cognition. Different individuals lean toward one of these processes with varying degrees of strength, influencing day-to-day behavior, perceptions, and decisions. Thinking dispositions might influence, at the same time, vaccine acceptance and perceived risks of vaccine-preventable disease, but the implications of individuals’ cognitive differences for vaccination uptake have seldom been addressed from a sociological standpoint.
Objective
We bridge this gap by adopting a dual-process framework of cognition and investigate how thinking styles have a direct association with vaccine hesitancy and an indirect one through perceptions of risk.
Methods
We use data from original surveys carried out between September and November 2019 on a sample of the Italian population, participating in an online panel run by a major Italian survey company. We use Karlson, Holm, and Breen (KHB) decomposition to compare coefficients of nested-nonlinear models, separate the direct and indirect association of cognitive processes with vaccine hesitancy, and disentangle the contribution of each measure of risk perception.
Results
Net of individual socio-demographic characteristics, intuitive thinking is positively associated with the likelihood of being vaccine hesitant, and this direct association is as important as the indirect one through risk perceptions. Affective risk perceptions account for over half of the indirect association, underlining the centrality of affective versus probabilistic approaches to risk perception.
Conclusion
This study contributes to the existing literature by highlighting the importance of including cognitive characteristics in vaccine hesitancy research, and empirically showing individuals' qualitatively complex perceptions of risks. Taking into account individuals’ preferred cognitive style and affective concerns might be important in developing better tailored communication strategies to contain vaccine hesitancy.
... The successful transfer of argumentation-based inoculation provides further impetus to scholarly analyses of flawed argumentation and how that is used to disinform. Inventories of flawed rhetoric have been compiled for populist politicians (Blassnig et al., 2019), anti-vaccination activists (Jacobson et al., 2007), or by people who spread conspiracy theories (Lewandowsky et al., 2015(Lewandowsky et al., , 2018. The underlying rationale of those inventories is that cognition that jettisons normative standards of truth-finding is unlikely to be a reality-tracking device, thereby affording a potential opportunity for people to learn to avoid such flawed argumentation. ...
We report the results of a preregistered study that tested the effectiveness of inoculating participants against Islamophobic and radical-Islamist disinformation. Participants in the experimental (inoculation) condition watched a video that explained common rhetorical markers of radical-Islamist and Islamophobic disinformation that had been identified in an analysis of YouTube content. The information was presented in a neutral context not involving Islam and focused on analysis of the misleading argumentation. The control group watched a video about an unrelated topic. Participants were then exposed to target videos with “gateway” content that constituted an entry point to potential Islamist or Islamophobic radicalization. Both videos contained numerous items of disinformation. Participants then answered a variety of questions such as how likely they were to share the video, their level of agreement, and their perceived accuracy of the video. Participants who had received the inoculation displayed less agreement with the video content, perceived the video as less reliable, and were less likely to share it in comparison with participants in the control group. The study provides support for the use of argument-based inoculation in combatting extremist messages.
... Les blogues qui critiquent la vaccination ont aussi un effet très négatif (Nan et Madden, 2012). Malgré les erreurs de logique, la pensée magique et les distorsions de la réalité que l'on retrouve sur les sites anti-vaccination (Jacobson, Targonski et Poland, 2007), les histoires et les images d'enfants rendus malades par un vaccin sont si impressionnantes qu'elles restent imprimées dans l'esprit et peuvent avoir une influence négative sur la prise de décision des parents. ...
... Conspiracy theories about aspects of medicine have long existed, positing that sinister motivations underpin everything from vaccination campaigns to cancer treatment [1][2][3][4][5][6][7]. While this has been a problem since before the dawn of social media, it has been hugely exacerbated by the dubious amplification [8] that social media provides. ...
The coronavirus pandemic has seen a marked rise in medical disinformation across social media. A variety of claims have garnered considerable traction, including the assertion that COVID is a hoax or deliberately manufactured, that 5G frequency radiation causes coronavirus, and that the pandemic is a ruse by big pharmaceutical companies to profiteer off a vaccine. An estimated 30% of some populations subscribe some form of COVID medico-scientific conspiracy narratives, with detrimental impacts for themselves and others. Consequently, exposing the lack of veracity of these claims is of considerable importance. Previous work has demonstrated that historical medical and scientific conspiracies are highly unlikely to be sustainable. In this article, an expanded model for a hypothetical en masse COVID conspiracy is derived. Analysis suggests that even under ideal circumstances for conspirators, commonly encountered conspiratorial claims are highly unlikely to endure, and would quickly be exposed. This work also explores the spectrum of medico-scientific acceptance, motivations behind propagation of falsehoods, and the urgent need for the medical and scientific community to anticipate and counter the emergence of falsehoods.
... We have already mentioned cognitive bias. In the case of vaccine risk misperception, people are influenced by at least three cognitive determinants: the desire to find order and predictability in random data; a difficulty in detecting and correcting biases in incomplete and unrepresentative data; an eagerness to interpret ambiguous and inconsistent data to fit theories and expectations [46]. This is much more structured and erroneous than a simple "confirmation bias" [47]. ...
Vaccines are arguably a public health success story as well as an incredibly cost-effective medical resource. Despite this, worldwide concerns about their safety are growing, with the risk of increased morbidity and mortality in vaccine-preventable diseases because of vaccine refusal. The global political trend in developed countries is to increasingly reduce mandates and the compulsory nature of vaccination programs. This is due to strong opposition from anti-vaccination movements and groups. While these have existed since the beginnings of vaccinology, they have recently gained a strong foothold through massive exploitation of the media and especially the internet. This has led to widespread misinformation and greater difficulty for governments and health institutions in dealing with parents’ concerns and misconceptions. Common strategies in order to maintain a high degree of public acceptance of vaccines include the enhancement of adverse effect reporting systems, the enrichment of scientific literature, and the dissemination of targeted information to parents and health care providers. Vaccine risk perception, in fact, largely exceeds the evidence and is linked to well-known general population cognitive bias, which must be recognized and corrected. Although there is no doubt about the convenience of universal vaccination, a lively international debate is underway with regard to the legitimacy of mandatory vaccination programs. Most scientists agree that the individual’s right to self-determination should be preserved. The only way to simultaneously protect the right to health is to introduce an informed refusal model, which aims to guarantee the highest coverage rates for vaccination.
... The phenomenon of «no vax» is not a novelty in the history 24 and the literature on anti-vaccination movements, their development and interpretations is wide with the first works dating back to almost 60 years ago (Beck 1960;Kaufman 1967;Porter, Porter 1988;Arnup 1992;Swales 1992;Durbach 2000;Poland, Jacobson 2001;Spier 2001;Wolfe, Sharp 2002;Blume 2006;Salmon et alii 2006;Jacobson, Targonski, Poland 2007;Tafuri et alii 2011). ...
Reviewing recent literature on the topic, this article reflects from a socio-logical perspective on the influence that perinatal and infant experts’ authority and scientific knowledge have on the cultures, policies and practices of parenthood in contemporary societies. Here the author refers mainly to the heterosexual parent-hood and not also to the homogenitorial families that would require a separate discussion. The geographical and social context the author refers to is mainly Italy. After having illustrated the main characteristics of the “expert-led” model in perina-tal and infant area and the reasons why it has become increasingly the hegemonic model in the parenting and childrearing cultures and practices, the article presents an overview of the Italian context illustrating data on pregnancy, childbirth, breast-feeding and vaccination. Then it questions about possible research developments in exploring the use that the policy makes of the experts’ knowledge and scientific evi-dence and the implications of this use. Finally it reflects on the growing diffusion of anti-science movements in perinatal and infant area.
... However, vaccination rates (for diseases such as measles) in the U.S. (e.g., Connecticut) have continued to fall [24]. In fact, an antivaccine sentiment has been building in the U.S. for decades [60][61][62]. In 2019, the debate over the vaccination requirement in schools was reignited [63][64][65]. ...
Text analysis has been used by scholars to research attitudes toward vaccination and is particularly timely due to the rise of medical misinformation via social media. This study uses a sample of 9581 vaccine-related tweets in the period January 1, 2019 to April 5, 2019. The time period is of the essence because during this time, a measles outbreak was prevalent throughout the United States and a public debate was raging. Sentiment analysis is applied to the sample, clustering the data into topics using the term frequency–inverse document frequency (TF-IDF) technique. The analyses suggest that most (about 77%) of the tweets focused on the search for new/better vaccines for diseases such as the Ebola virus, human papillomavirus (HPV), and the flu. Of the remainder, about half concerned the recent measles outbreak in the United States, and about half were part of ongoing debates between supporters and opponents of vaccination against measles in particular. While these numbers currently suggest a relatively small role for vaccine misinformation, the concept of herd immunity puts that role in context. Nevertheless, going forward, health experts should consider the potential for the increasing spread of falsehoods that may get firmly entrenched in the public mind.
... Still more articles focus on the deficits of those who refuse or question vaccines, examining "reasoning flaws" associated with vaccine concern [21], arguing for the ethical grounds for mandating vaccines [22,23], and counseling physicians and other healthcare providers on how to respond to vaccine concerns [24,25]. These studies frequently use analyses of hesitancy as a basis for these findings. ...
Background
Improving persuasion in response to vaccine skepticism is a long-standing problem. Elective nonvaccination emerging from skepticism about vaccine safety and efficacy jeopardizes herd immunity, exposing those who are most vulnerable to the risk of serious diseases.
Objective
This article analyzes vaccine sentiments in the New York Times as a way of improving understanding of why existing persuasive approaches may be ineffective and offers insight into how existing methods might be improved. We categorize pro-vaccine and anti-vaccine arguments, offering an in-depth analysis of pro-vaccine appeals and tactics in particular to enhance current understanding of arguments that support vaccines.
Methods
Qualitative thematic analyses were used to analyze themes in rhetorical appeals across 808 vaccine-specific comments. Pro-vaccine and anti-vaccine comments were categorized to provide a broad analysis of the overall context of vaccine comments across viewpoints, with in-depth rhetorical analysis of pro-vaccine comments to address current gaps in understanding of pro-vaccine arguments in particular.
Results
Appeals across 808 anti-vaccine and pro-vaccine comments were similar, though these appeals diverged in tactics and conclusions. Anti-vaccine arguments were more heterogeneous, deploying a wide range of arguments against vaccines. Additional analysis of pro-vaccine comments reveals that these comments use rhetorical strategies that could be counterproductive to producing persuasion. Pro-vaccine comments more frequently used tactics such as ad hominem arguments levied at those who refuse vaccines or used appeals to science to correct beliefs in vaccine skepticism, both of which can be ineffective when attempting to persuade a skeptical audience.
Conclusions
Further study of pro-vaccine argumentation appeals and tactics could illuminate how persuasiveness could be improved in online forums.
In the 20th century, the introduction of multiple vaccines significantly reduced childhood morbidity, mortality, and disease outbreaks. Despite, and perhaps because of, their public health impact, an increasing number of parents and patients are choosing to delay or refuse vaccines. These individuals are described as "vaccine hesitant." This phenomenon has developed due to the confluence of multiple social, cultural, political, and personal factors. As immunization programs continue to expand, understanding and addressing vaccine hesitancy will be crucial to their successful implementation. This review explores the history of vaccine hesitancy, its causes, and suggested approaches for reducing hesitancy and strengthening vaccine acceptance. [Pediatr Ann. 2015;44(4):e71-e75.].
Copyright 2015, SLACK Incorporated.
Despite the recent emphasis on science practices, little work has focused on teachers' knowledge of these key learning goals. The development of high quality assessments for teachers' pedagogical content knowledge (PCK) of science practices, such as argumentation, is important to better assess the needs of teachers and to develop supportive teacher education experiences. In this paper, we present lessons learned from a development process to conceptualize, design, and pilot a measure of teachers' PCK of argumentation. We use the results from our pilot test with 103 middle school science teachers, cognitive interviews with 24 middle school science teachers, and feedback from 10 advisors to present these lessons learned. Specifically, this work resulted in the refinement of our conceptualization of PCK of argumentation in two areas: (1) Moving beyond pseudoargumentation of surface level features to target the quality of structural components and students' dialogic interactions as well as the use of instructional strategies that align with student needs and (2) Focusing on dialogic argumentation in terms of the quality of student interactions in which they build off of and critique each others' claims, rather than goals such as persuasion that are difficult to observe. In addition, the iterative design process suggested that PCK of argumentation assessments should use classroom contexts (such as vignettes, student writing, and video) to activate teachers' knowledge in use by connecting to their prior experiences; however, the student argumentation examples need to highlight one specific strength or challenge and provide sufficient detail around the example to focus the assessment item. © 2015 Wiley Periodicals, Inc. J Res Sci Teach
Vaccines are one of mankind's greatest medical advances, preventing many of the infectious diseases that have ravaged the human population throughout history. A variety of maladies have been attributed to the use of vaccination. Before discussing about how toxicity is assessed and how this assessment is regulated, this chapter examines a few of these attributions, including immune system “overload”, increase in allergy/atopy, and autism. It deals with regulations covering preventive vaccines; that is, vaccines that are developed specifically to prevent infection. The most specific understanding of vaccine development comes at the most proximate level, published as Food and Drug Administration (FDA) guidance documents. Next, the chapter discusses specifics of guidance documents related to safety. '. End-point assessment for vaccine studies is very similar to any other biopharmaceutical product, with some minor exceptions. The chapter also focuses on FDA, EMA, and WHO regulations as well as clinical safety assessment of vaccines.
Le valutazioni di HTA rappresentano uno strumento in-dispensabile per i decision makers e per i professionisti di salute quando occorre valutare l’adozione di nuovi vaccini o nuove strategie di vaccinazione per massimizzare i benefici di salute. Le attuali evidenze scientifiche disponibili a livello inter-nazionale, valutate con un approccio di Health Technology Assessment, evidenziano come l’estensione della vaccinazione antimeningococcica contro i sierogruppi A, C, W e Y anche ai bambini in età scolare (già attuata in Regione Toscana) e ai giovani adulti, oltre ai bambini nel secondo anno di vita e agli adolescenti, permetterebbe ai gruppi di popolazione a rischio di infezione e di malattia di mantenere nel tempo un adeguato livello anticorpale protettivo. Una strategia multi-coorte, inoltre, permetterebbe di recuperare i giovani non precedentemente vaccinati. Sebbene la malattia causata da N. meningitidis non pre-senti una elevata incidenza, essa ha un decorso particolarmente severo e talvolta letale. Il costo della malattia e delle sue conseguenze è ingente sia per il SSN che per l’intera società, senza considerare i costi intangibili determinati dalla morte prematura di soggetti giovani e dalla perdita di qualità di vita dei sopravvissuti e dei caregivers. I dati raccolti in questo report HTA sono a supporto dell’estensione della vaccinazione anti-meningococco contro i sierogruppi A, C, W e Y anche ai bambini di 6 anni e ai giovani adulti per rafforzare la lotta globale alla patologia invasiva da meningococco. Capitolo 14Conclusioni
While most Canadian parents ensure that their children are immunized on time, some are hesitant about vaccination, delay vaccinations or outright refuse recommended vaccines. This practice point offers clinicians evidencebased guidance on how to work with vaccine-hesitant parents, especially those with safety concerns. Suggested steps include: understanding the specific parental vaccine concerns; using motivational interviewing techniques; staying on message and using clear language to present evidence of disease risks, and vaccine benefits and risks fairly and accurately; informing parents about the rigour of the vaccine safety system; addressing issues related to pain from immunization; and avoiding dismissal of children from a practice because parents refuse to immunize. Because immunization is one of the most important preventive health measures, responsible for saving literally millions of lives, addressing the concerns of vaccine-hesitant parents must be a priority for health care providers.
This article discusses a study of flu vaccine uptake and hesitancy in a rural community during the 2009–2010 H1N1 pandemic flu season. In it, we explore study participants’ understanding of the relationship between vaccines, illness, and immunity, as well as parent intentionality in accepting or forgoing flu vaccines for their children. Our research offers novel conclusions about how people respond to the development and implementation of vaccines for newly emerging flu strains and establishes a warrant for qualitative research on vaccination practices that attends to participants’ views about vaccines in the context of their overall ideas about health. Our findings suggest that more accurate understandings of people’s beliefs and experiences of vaccination can be developed through qualitative research that values vernacular discourse. Our findings also suggest that influenza vaccination provides a fruitful context in which to study vaccine hesitancy and refusal. Finally, our study demonstrates that vaccine concerns are more demographically widespread than is presumed by current research.
Many studies have investigated how individual factors, message factors, and combinations of individual and message factors influence choice of information processing strategy. This commentary probes a complex contemporary personal and policy issue to illustrate the drawbacks of relying on subjects’ self-reports of reasoning strategy, or the conclusions of subjects’ decision-making processes, to distinguish between heuristic and systematic information processing. Moreover, it argues that to reach their audiences effectively, science communicators need both a sophisticated understanding of the tradeoffs in the science and health issues they cover, and a knowledge of the commonly used heuristics that influence individuals’ costs-benefits analyses.
Parents in the US and other societies are increasingly refusing to vaccinate their children, even though popular anti-vaccine myths e.g. vaccines cause autism have been debunked. This book explains the epistemic and moral failures that lead some parents to refuse to vaccinate their children. First, some parents have good reasons not to defer to the expertise of physicians, and to rely instead upon their own judgments about how to care for their children. Unfortunately, epistemic self-reliance systematically distorts beliefs in areas of inquiry in which expertise is required (like vaccine immunology). Second, vaccine refusers and mainstream medical authorities are often committed to different values surrounding health and safety. For example, while vaccine advocates stress that vaccines have low rates of serious complications, vaccine refusers often resist vaccination because it is unnatural and because they view vaccine-preventable diseases as a natural part of childhood. Finally, parents who refuse vaccines rightly resist the utilitarian moral arguments for the greater good that vaccine advocates sometimes make. Unfortunately, vaccine refusers also sometimes embrace a pernicious hyper-individualism that sanctions free-riding on herd immunity and that cultivates indifference to the interpersonal and social harms that unvaccinated persons may cause.
Background:
Official French health care policy recommends vaccinations against hepatitis B for all infants and at-risk adults. Attendees at our free testing center for sexually transmitted infections (FTC-STI) routinely express hepatitis B vaccine hesitancy. We aimed in this exposed population to explore the extent of knowledge concerning HBV infection, to quantify HBV vaccine refusal, and to identify the reasons for this refusal.
Methods:
During a 3-month period in 2013, all attendees at the Grenoble FTC-STI were given an anonymous questionnaire exploring their knowledge of hepatitis B, perception of the hepatitis B vaccine, acceptance of free same-day hepatitis B vaccination, and reasons for refusing this offer (where applicable).
Results:
The questionnaire was completed by 735 attendees (64.7% of those attending during the study period)(59.9% men; age 27.9±9.2). Most respondents identified hepatitis B as a potentially severe, potentially lifelong illness existing in France. Concerning the hepatitis B vaccine, less than 50% totally or mostly agreed that it is safe; when asked whether the vaccine is dangerous, 44.2% answered "I don't know" and 14.0% agreed; when asked whether the vaccine is "not well characterized," 45.0%, answered "I don't know" and 26.5% agreed. When asked whether they mistrust the hepatitis B vaccine or all vaccines in general, 39.0% and 28.9% of those unvaccinated agreed, respectively. Two thirds refused to get vaccinated on the same day. When asked whether they were afraid of the adverse effects of this vaccine, only 18.7% disagreed.
Conclusion:
Negative perceptions of the hepatitis B vaccine are widespread in this at-risk population. Consequently, a successful communication strategy must reassure this at-risk population of the vaccine's innocuous nature.
Increasing vaccine hesitancy among parents in high-income countries and the resulting drop in early childhood immunization constitute an important public health problem, and raise the issue of what policies might be taken to promote higher rates of vaccination. This article first outlines the background of the problem of increasing vaccine hesitancy. It then explores the pros and cons of 3 types of policy: (a) interventions focused on increasing awareness of the benefits of vaccination while eliminating mistaken perceptions of risks, (b) “nudges,” which make certain choices more likely to be voluntarily chosen by manipulating the decision environment, and (c) policies that impose costs to make nonvaccination undesirable even for parents who are hesitant. It argues that a wide range of policies, including coercive policies, is desirable from a public health perspective, as the least intrusive policies alone are unlikely to achieve and sustain the important public good of herd immunity.
Objective: To evaluate the prescription of metformin (contraindication, dosage, adverse effects) for the treatment of type 2 diabetic patients, attending a low-complexity health institution in Cartagena de Indias, Colombia. Design: Descriptive study with a pharmacoepidemiological focus, specifically aimed at the field of studies on drug usage, and based on data collected from medical records of patients with type 2 diabetes. Setting: Performed in an institution of Primary Health Care in the city of Cartagena de Indias, Colombia. Participants: 331 type 2 diabetic patients, over 18 years old, who were enrolled in diabetes care program during 2013 and 2014 and who had been under supervision for at least six months. Main measurements: Appropriate prescription of metformin based on three conditions: 1) absence of contraindications for the use of the drug, 2) dose prescription according to the estimated glomerular filtration rate (GFR) and 3) prevention of gastrointestinal adverse effects. Results: 16.4 % (C.I. 95 % 12.5 % - 21.1 %) of the patients had some contraindication for the use of metformin. 27.4 % (C.I. 95 % 22.5 % - 32.9 %) were prescribed a dose inappropriate for the GFR. 54.4 % (C.I. 95 % 48.6 % - 60.1 %) were prescribed the drug inappropriately). Conclusion: Though Metformin is considered the initial first-line therapy for the management of patients with type 2 diabetes, in a high percentage of cases it is prescribed inappropriately, it is administered in spite of being contraindicated, and its dosage does not consider the GFR.
In this study, the constructive communication process of anti-vaccination advocates is explored to provide insight into the challenges of communicating with an engaged, educated public that is distrustful of mainstream medical and governmental organizations. Using the circuit of culture as a theoretical and methodological model, this article examines how anti-vaccination advocates use social media to construct and reinforce a belief system that counters dominate understandings of health. Findings show that, through online communication, anti-vaccination advocates create shared cultural constructs embracing the identity of health information crusader, critic, and expert. This community consumes, produces, and distributes information that reframes mainstream health information and reinforces shared values. The purposes of this study are to better understand the culture of anti-vaccination advocates, identify communication barriers, and offer practical implications for health care professionals.
La Corte Suprema ordenó la vacunación de un menor cuyos padres se negaron a su inoculación. Aunque la Corte alcanzó el resultado correcto, lo hizo de manera errónea, no fundamentando adecuadamente la procedencia de la vacunación obligatoria. La Corte debería haberse referido al balancing-test de la autonomía individual y la salud pública, protegiendo a esta última, rechazando además los erróneos fundamentos argüidos por el movimiento antivacunas.
Over the past 100 years, an increasing array of vaccines has been introduced into the Canadian market and yet optimal use depends on public demand and acceptance of these products. In the 1990s, research focused on key barriers to vaccine uptake, highlighting the importance of barriers to access and "missed opportunities" for vaccination. In this century the focus is on vaccine hesitancy, which is influenced by factors such as complacency, convenience and confidence. This phenomenon is not new but some of its drivers include an increasingly crowded immunization schedule, heightened societal concerns about risk over benefit, and a rise in health consumerism. Understanding and addressing vaccine hesitancy will be critical to preventing it from undermining the success of immunization in the future. While more research is needed, there are both practitioner-based resources to optimize dialogue with vaccine-hesitant parents and program-based resources to address vaccine hesitancy at a population-based and societal level.
Résumé
Les vaccins ont sauvé des millions de vie et ont réduit la gravité de nombreuses infections. Une diminution de la couverture vaccinale se traduit aujourd’hui par la ré-émergence d’épidémies d’oreillons, de coqueluche, de rougeole et de varicelle. Beaucoup d’individus ne reconnaissent pas l’efficacité de la vaccination et en redoutent les effets secondaires. La principale préoccupation porte sur la sécurité des vaccins. Le manque d’information pèse moins que le manque de confiance dans les autorités sanitaires. La plus grande responsabilité de l’individu, le respect de son libre arbitre, peuvent conduire les autorités à une moindre promotion du « devoir vaccinal » qui est un devoir social. L’attitude des individus est guidée par leurs croyances de santé qui sont soutenues par une perception du risque souvent erronée. De plus, un lobbying anti-vaccinal sournois joue sur les peurs et utilise des biais de raisonnement que les médias contribuent à amplifier. Ainsi, l’analyse des freins à la vaccination, tant en population générale que chez les professionnels de santé, le démontage des arguments développés par les ligues anti-vaccins, une vigilance à l’égard des « fake news » doivent permettre une communication concertée, transparente, claire et efficace afin de limiter la survenue de morts évitables.
A three part investigation of the factors that might influence uptake of immunisation was carried out in Maidstone Health Authority; this included studies of the computer system and attitudes of parents and professionals. Several problems with immunisation scheduling, information transfer between general practitioners and clinics and the computer centre, and validity of computer information were identified. The attitudes of parents, relatives, and friends were generally favourable, although parents reported a lack of knowledge about the disease and vaccine and lack of advice from professionals. Perceived contraindications to immunisation, particularly a history of measles, were important reasons for non-uptake. Professionals' perceptions of contraindications, however, were at variance with Department of Health and Social Security guidelines and none of the recorded contraindications was valid. Calculations of potential uptake suggest that a 90% target uptake is feasible and recommendations are made for changes in services.
A study of a cohort of children in Maidstone Health Authority examined the reasons for the failure to achieve targets for the uptake of measles immunization. Parents were interviewed before they were notified about measles immunization to determine their attitudes, beliefs and intentions regarding measles immunization and a further review was held with those whose child had no record of the immunization by the age of 20 months. The initial interview showed that most parents have a favourable attitude to measles immunization. However, many lacked knowledge, especially about valid contraindications, and claimed not to have received advice from a doctor or health visitor. The most common reasons for non-uptake of measles immunization were: the child had already had measles, concern about contraindications and delay owing to illness. This points to the importance of increasing doctors' and health visitors' knowledge of Department of Health and Social Security guidelines regarding valid contraindications and to the role of health visitors in promoting uptake. However there is also evidence that the gap between actual and target levels of uptake may be less than official figures suggest.
To assess the impact of anti-vaccine movements that targeted pertussis whole-cell vaccines, we compared pertussis incidence in countries where high coverage with diphtheria-tetanus-pertussis vaccines (DTP) was maintained (Hungary, the former East Germany, Poland, and the USA) with countries where immunisation was disrupted by anti-vaccine movements (Sweden, Japan, UK, The Russian Federation, Ireland, Italy, the former West Germany, and Australia). Pertussis incidence was 10 to 100 times lower in countries where high vaccine coverage was maintained than in countries where immunisation programs were compromised by anti-vaccine movements. Comparisons of neighbouring countries with high and low vaccine coverage further underscore the efficacy of these vaccines. Given the safety and cost-effectiveness of whole-cell pertussis vaccines, our study shows that, far from being obsolete, these vaccines continue to have an important role in global immunisation.
All US states require proof of immunization for school entry. Exemptions are generally offered for medical, religious, or philosophical reasons, but the health consequences of claiming such exemptions are poorly documented.
To quantify the risk of contracting measles among individuals claiming religious and/or philosophical exemptions from immunization (exemptors) compared with vaccinated persons, and to examine the risk that exemptors pose to the nonexempt population.
Population-based, retrospective cohort study of data from 1985 through 1992, collected by the Measles Surveillance System of the Centers for Disease Control and Prevention, as well as from annual state immunization program reports on prevalence of exemptors and vaccination coverage. The study group was restricted to individuals aged 5 to 19 years. To empirically determine and quantify community risk, a mathematical model was developed that examines the spread of measles through communities with varying proportions of exemptors and vaccinated children.
Relative risk of contracting measles for exemptors vs vaccinated individuals based on cohort study data. Community risk of contracting measles derived from a mathematical model.
On average, exemptors were 35 times more likely to contract measles than were vaccinated persons (95% confidence interval, 34-37). Relative risk varied by age and year. Comparing the incidence among exemptors with that among vaccinated children and adolescents during the years 1985-1992 indicated that the 1989-1991 measles resurgence may have occurred 1 year earlier among exemptors. Mapping of exemptors by county in California indicated that exempt populations tended to be clustered in certain geographic regions. Depending on assumptions of the model about the degree of mixing between exemptors and nonexemptors, an increase or decrease in the number of exemptors would affect the incidence of measles in nonexempt populations. If the number of exemptors doubled, the incidence of measles infection in nonexempt individuals would increase by 5.5%, 18.6%, and 30.8%, respectively, for intergroup mixing ratios of 20%, 40%, and 60%.
These data suggest the need for systematic review of vaccine-preventable incidents to examine the effect of exemptors, increased surveillance of the number of exemptors and cases among them, and research to determine the reasons why individuals claim exemptions.
The risk of vaccine-preventable diseases among children who have philosophical and religious exemptions from immunization has been understudied.
To evaluate whether personal exemption from immunization is associated with risk of measles and pertussis at individual and community levels.
Population-based, retrospective cohort study using data collected on standardized forms regarding all reported measles and pertussis cases among children aged 3 to 18 years in Colorado during 1987-1998.
Relative risk of measles and pertussis among exemptors and vaccinated children; association between incidence rates among vaccinated children and frequency of exemptors in Colorado counties; association between school outbreaks and frequency of exemptors in schools; and risk associated with exposure to an exemptor in measles outbreaks.
Exemptors were 22.2 times (95% confidence interval [CI], 15.9-31.1) more likely to acquire measles and 5.9 times (95% CI, 4.2-8.2) more likely to acquire pertussis than vaccinated children. After adjusting for confounders, the frequency of exemptors in a county was associated with the incidence rate of measles (relative risk [RR], 1.6; 95% CI, 1.0-2.4) and pertussis (RR, 1.9; 95% CI, 1.7-2.1) in vaccinated children. Schools with pertussis outbreaks had more exemptors (mean, 4.3% of students) than schools without outbreaks (1. 5% of students; P =.001). At least 11% of vaccinated children in measles outbreaks acquired infection through contact with an exemptor.
The risk of measles and pertussis is elevated in personal exemptors. Public health personnel should recognize the potential effect of exemptors in outbreaks in their communities, and parents should be made aware of the risks involved in not vaccinating their children.
The objective of this study was to understand how low income, inner-city parents of preschool children think about childhood diseases and prevention and the impact that this has on late receipt of vaccines.
Parents of all children born between January 1, 1991, and May 31, 1995, whose child received medical assistance and health care at one of four inner-city, primary care clinics in Pittsburgh, PA, completed a telephone interview and gave consent for a vaccine record review. The main outcome measures were lateness for first and third diphtheria and tetanus toxoids and pertussis vaccines (DTP) and not receiving at least four DTP, three polio virus containing and one measles, mumps and rubella (MMR) doses by 19 months.
A total of 483 parents participated. Fifteen percent of children were late for the first DTP, 52% for the third DTP, and 40% had not received at least four DTP, three polio and one MMR by 19 months of age. Statistically significant factors associated with lateness at 19 months included: having three or more children, having two children, beliefs regarding the severity of immunization side effects, and being African American.
The results of this study indicate that a combination of life circumstances, as well as cognitive factors were associated with late immunization.
In this paper, we examine the phenomenon of 'clustering of exemptions' to childhood vaccination, and the dangers this poses both to those exempted as well as the general population. We examine how clusters of exemptions might form through collective action as described by Thomas Schelling, and how religious groups who live in close proximity to one another can "self-select" in a way that exacerbates this phenomenon. Given the growing number of exemptions and the increasing visibility of the anti-vaccine movement, policy makers must be vigilant for dangerous clustering in order to avoid loss of herd immunity.
Hepatitis B vaccine is recommended for all infants, and the series may be started during the delivery admission. For infants who are born either to women who are positive for hepatitis B surface antigen (HBsAg) or to women whose HBsAg status is unknown, vaccination should be started within 12 hours of birth to prevent perinatal and early childhood hepatitis B virus infection. Because of concerns about mercury exposures from vaccines that contain thimerosal, the United States Public Health Service (USPHS) and the American Academy of Pediatrics (AAP) recommended in July 1999 that the first dose of hepatitis B vaccine be deferred until 2-6 months of age but only for infants who are born to HBsAg-negative women. To assess the impact on birth-dose vaccine coverage for infants who are born to women with unknown HBsAg status, we measured coverage before and after July 1999.
A sample of Michigan infants who were born to women whose HBsAg status was either unknown or missing were identified by reviewing newborn screening cards for infants who were born during 1) March-April 1999 (before recommendation changes [T1]); 2) July 15-September 15, 1999 (immediately after recommendation changes [T2]); and 3) March-April 2000 (6 months after resumption of pre-1999 practices were recommended [T3]). We verified maternal HBsAg screening and newborn hepatitis B vaccination by reviewing infant and maternal hospital records.
Of 1201 infants who were born to women whose HBsAg status was indicated as unknown or missing on the newborn screening card during the 3 time periods, 216 (18%) were born to women whose status was truly unknown at the time of delivery, as determined by medical record review. During T1, 53% of these 216 infants received hepatitis B vaccine before hospital discharge, compared with 7% of infants who were born during T2 and 57% of infants who were born during T3. During T1, 19% of these infants received hepatitis B vaccine within 12 hours of birth compared with 1% of infants who were born during T2 and 14% of infants who were born during T3.
Hepatitis B vaccine birth-dose coverage for infants who were born to women whose HBsAg status was unknown at the time of delivery was already low in Michigan before the July 1999 USPHS/AAP Joint Statement but decreased significantly during the 2 months after the USPHS/AAP Joint Statement. Abrupt changes in established vaccination recommendations for lower risk children may lead to decreased coverage among higher risk children. Increases in hepatitis B vaccine coverage at birth are necessary to reduce the risk of perinatal infection for infants who are born to women with unknown HBsAg status.
Controversy over the measles, mumps, and rubella (MMR) vaccine has reduced uptake, raising concerns of a future disease epidemic.
To explore parents' accounts of decision making relating to the MMR vaccine controversy, identifying uptake determinants and education needs.
Qualitative interviews analysed using the 'framework' approach.
Five general practices in the Leeds area, 2002-2003.
Sixty-nine interviews conducted with parents of children aged between 4 and 5 years, and 12 interviews with primary care practitioners, managers and immunisation coordinators serving participating sites. Participants were interviewed one-to-one in a place of their choice.
The vaccination decision is primarily a function of parental assessments of the relative acceptability and likelihood of possible outcomes. For most parents the evidence of science and medicine plays little role in the decision. Although local general practitioners and health visitors are trusted information sources, the influence of primary care providers on the vaccination decision is limited by concerns over consultation legitimacy, discussion opportunity, and perceptions of financial and political partiality. Parents and practitioners identify a need for new approaches to support decisions and learning when faced with this and similar healthcare controversies. These include new collaborative approaches to information exchange designed to transform rather than supplant existing parent knowledge as part of an ongoing learning process.
The study identified new ways in which parents and practitioners need to be supported in order to increase understanding of medical science and secure more informed decisions in the face of health controversy.
In order to prepare the national campaigns to promote measles-mumps-rubella (MMR) and Hepatitis B immunization, the French Committee of Health Education (CFES) and his partners caried out several surveys about opinions, attitudes and practices of French parents as regards childhood immunization. This article presents the main results of the «Baromètre Santé Adultes» (Health Barometer) of adults aged 18 to 75 years (november/december 1992 and and november/december 1993) and those of two qualitative researches (1993 and 1995). These studies showed that immunization against the MMR and Hepatitis B were well accepted by parents. However, they also identified some barriers to a better immunization coverage. Some characteristics are related to a poor opinion as regards these immunizations: unawareness of the severity of these diseases, choice of homeopathic or acupuncture practices, legal status of the vaccination (only recommended), living in Southern France, having a high level of education and having a high degree of information and medical culture. General practitioners could contribute to overcome some of these barriers.
Context The risk of vaccine-preventable diseases among children who have philosophical
and religious exemptions from immunization has been understudied.Objectives To evaluate whether personal exemption from immunization is associated
with risk of measles and pertussis at individual and community levels.Design, Setting, and Participants Population-based, retrospective cohort study using data collected on
standardized forms regarding all reported measles and pertussis cases among
children aged 3 to 18 years in Colorado during 1987-1998.Main Outcome Measures Relative risk of measles and pertussis among exemptors and vaccinated
children; association between incidence rates among vaccinated children and
frequency of exemptors in Colorado counties; association between school outbreaks
and frequency of exemptors in schools; and risk associated with exposure to
an exemptor in measles outbreaks.Results Exemptors were 22.2 times (95% confidence interval [CI], 15.9-31.1)
more likely to acquire measles and 5.9 times (95% CI, 4.2-8.2) more likely
to acquire pertussis than vaccinated children. After adjusting for confounders,
the frequency of exemptors in a county was associated with the incidence rate
of measles (relative risk [RR], 1.6; 95% CI, 1.0-2.4) and pertussis (RR, 1.9;
95% CI, 1.7-2.1) in vaccinated children. Schools with pertussis outbreaks
had more exemptors (mean, 4.3% of students) than schools without outbreaks
(1.5% of students; P = .001). At least 11% of vaccinated
children in measles outbreaks acquired infection through contact with an exemptor.Conclusions The risk of measles and pertussis is elevated in personal exemptors.
Public health personnel should recognize the potential effect of exemptors
in outbreaks in their communities, and parents should be made aware of the
risks involved in not vaccinating their children.
Background:
Measles is the most transmissible disease known to man. During the 1980s, the number of measles cases in the United States rose dramatically. Surprisingly, 20% to 40% of these cases occurred in persons who had been appropriately immunized against measles. In response, the United States adopted a two--dose universal measles immunization program. We critically examine the effect of vaccine failure in measles occurring in immunized persons.
Methods:
We performed a computerized bibliographic literature search (National Library of Medicine) for all English-language articles dealing with measles outbreaks. We limited our search to reports of US and Canadian school-based outbreaks of measles, and we spoke with experts to get estimates of vaccine failure rates. In addition, we devised a hypothetical model of a school where measles immunization rates could be varied, vaccine failure rates could be calculated, and the percentage of measles cases occurring in immunized students could be determined.
Results:
We found 18 reports of measles outbreaks in very highly immunized school populations where 71% to 99.8% of students were immunized against measles. Despite these high rates of immunization, 30% to 100% (mean, 77%) of all measles cases in these outbreaks occurred in previously immunized students. In our hypothetical school model, after more than 95% of schoolchildren are immunized against measles, the majority of measles cases occur in appropriately immunized children.
Conclusions:
The apparent paradox is that as measles immunization rates rise to high levels in a population, measles becomes a disease of immunized persons. Because of the failure rate of the vaccine and the unique transmissibility of the measles virus, the currently available measles vaccine, used in a single-dose strategy, is unlikely to completely eliminate measles. The longterm success of a two-dose strategy to eliminate measles remains to be determined.(Arch Intern Med. 1994;154:1815-1820)
The safety of the combined oligosaccharide conjugate Haemophilus influenzae (Hib) type b (HbOC) and whole cell diphtheria-tetanus toxoids-pertussis (DTP) vaccine (Tetramune, HbOC-DTP; Lederle) in infancy was evaluated in 6644 recipients of this vaccine and compared with 3914 recipients of separate injections of whole cell DTP and HbOC vaccines when given as a three dose regimen to infants at 2, 4 and 6 months of age in each group. Of the total number of infants in the study, a subset of 1435 were enrolled into the study and then randomly assigned to receive either the Hib-DPT combined vaccine or the separate components. This subset was used to assess local and systemic side effects which were evaluated utilizing telephone interviews 48 to 72 hours after vaccine. The remaining children in the study population were enrolled in a nonrandomized manner. For these children parents were offered the experimental Hib-DPT vaccine and refusers were given HbOC and DTP. Both of these groups of children as well as the randomized subset described above were used to assess rates of episodes of hospitalization, emergency room utilization and sudden infant death syndrome in HbOC-DTP recipients and children who received HbOC and DTP separately. Immunogenicity was evaluated in 123 children by collection of a single serum sample 30 days after the third dose of HbOC-DTP. The observed immunogenicity was comparable to that observed in other recent studies for HbOC and DTP component antigens. The profile of local and systemic side effects observed was virtually identical to that observed after DTP plus HbOC given separately.(ABSTRACT TRUNCATED AT 250 WORDS)
Epidemiological evidence indicates infants immunised against diphtheria, pertussis and tetanus (DPT) are at decreased risk of sudden infant death syndrome (SIDS). Asymptomatic whooping cough and pyrogenic toxins of Staphylococcus aureus have been implicated in the aetiology of SIDS. The objectives of the present study were: (1) to determine if the DPT vaccine induced antibodies cross-reactive with the staphylococcal toxins; (2) to determine if antibodies to the pertussis toxin (PT) and the staphylococcal toxins were present in the sera of women during late pregnancy; (3) to examine the effects of infant immunisation on levels of antibodies to PT and the staphylococcal toxins; (4) to assess the effects of changes in immunisation schedules in the UK on the incidence and age distribution of SIDS. Enzyme-linked immunosorbent assays (ELISA) were used to measure binding of rabbit or human IgG to the DPT vaccine, PT, toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins A (SEA), B (SEB) and C (SEC). Neutralisation activity of anti-DPT serum was assessed by a bioassay for induction of nitric oxide from human monocytes by the staphylococcal toxins. Anti-DPT serum bound to the DPT vaccine, PT and each of the staphylococcal toxins. It also reduced the ability of the four toxins to induce nitric oxide from monocytes. In pregnant women, levels of IgG to PT, SEC and TSST-1 decreased significantly in relation to increasing weeks of gestation while antibodies to SEA and SEB increased. In infants’ sera there were significant correlations between levels of IgG bound to DPT and IgG bound to PT, TSST-1 and SEC but not SEA or SEB. Antibody levels to the toxins in infants declined with age; sera from infants ≤2 months of age had higher levels of IgG bound to the toxins than those older than 2 months. This pattern was observed for infants whose immunisation schedules began at 2 months of age or 3 months of age. The decrease in IgG bound to the toxins was, however, less for those immunised at 2 months. The decrease in SIDS deaths after the change in immunisation schedules was greatest in the 4–6-month age range. While DPT immunisation might prevent some unexplained infant deaths due to asymptomatic whooping cough, these data indicate that immunisation with DPT also induces antibodies cross-reactive with pyrogenic staphylococcal toxins implicated in many cases of SIDS. Passive immunisation of infants who have low levels of these antibodies might reduce further the numbers of these infant deaths.
Vaccines and the ability to prevent morbidity and mortality due to infectious diseases have been one of the greatest public health success stories. On a global level, it is one of the few cost-effective medical measures that result in universal benefit. Despite this, there is evidence of a growing anti-vaccine movement. In turn, this has, in some cases, resulted in major disruptions in vaccine programs, with resultant needless morbidity and mortality. Of interest are the factors that seem to contribute to the current trend of anti-vaccine sentiment. This paper will examine the current anti-vaccine movement and provide current examples. Finally, a review of suggestions for dealing with the anti-vaccine movement will be presented.
To determine the reasons that motivate parents to enrol or not enrol their child in a randomized, controlled vaccine trial.
Cross-sectional survey.
Offices of primary care physicians in Dartmouth, Nova Scotia, and Montreal, Quebec.
At the 2 sites, parents of 2-month-old infants at their first immunization visit who had decided to enrol (221) or not enrol (208) their child in 2 randomized pertussis vaccine trials.
Rates of enrolment in vaccine trials; attitudes about medical research; sources of information about pertussis.
Enrolment rates were 68% and 43% at the 2 sites. All parents agreed to answer questions about their decision to enrol or not enrol their child. The most common concerns resulting in nonenrolment were extra immunization 54% (26/48) and blood procurement 42% (20/48). Parents who did enrol their children were motivated to participate by the desire to contribute to medical knowledge (77% [170/221]), the desire to help others (48% [106/221]) and by the participation of their family physician (54% [120/221]). The enrollees' major sources of information about pertussis was health professionals or study personnel rather than the media.
Altruistic reasons motivate parents' decision to enrol a child in a randomized, controlled vaccine trial. Nonparticipating parents seem most concerned about painful procedures in the study. Parents' decisions regarding participation do not appear to be affected by adverse media attention regarding the purported adverse sequelae of pertussis vaccines.
Summary A study was undertaken in a rural community to examine the knowledge and attitude of parents towards the ongoing smallpox
vaccination programme and also to identify the factors responsible for the meagre coverage of smallpox vaccination. The study
revealed that the educational status of the parents had no bearing on health knowledge like causation, spread and prevention
of smallpox. The factors identified for meagre coverage of smallpox vaccination relate to situational, administrative as well
as psychological influences
Two hundred and one parents attending three child health clinics were questioned about both measles and immunisation against measles. Most parents were unaware of the symptoms and possible complications of measles and did not believe immunisation to be effective in preventing measles. They did not remember having talked to health professionals about immunisation.
The investigation is aimed at analysing from different aspects the complex nature of the barriers against vaccination and with this the prerequisites for the development of adequate motivations among the population. The pilot study is based on the detailed interviewing of 80 persons (30 parents or mothers with infants aged up to 15 months; 30 parents or mothers with children aged from six to ten years; 20 physicians). The group interviewed was additionally broken down into persons favouring vaccination (50%) and others skeptical about or opposed to vaccination (50%). The barriers against vaccination likely to influence the attitude of the population in the Federal Republic of Germany are mentioned below: In the general consciousness of health, health education and preventive medicine the idea of vaccination does not play an important role. Vaccination is not seen as a preventive means against the central risks of life (environmental burden, stress factors, road traffic, semiluxuries). The body is not expected to suffer lasting damage from infectious diseases in childhood; the knowledge of the risks resulting from childhood diseases or infectious diseases is minimal. Childhood ailments and infectious diseases successfully overcome by the sufferer tend to weaken the motivating insight into the necessity of vaccination. The general outbreak of infectious diseases and epidemics in the Federal Republic of Germany is considered rather unlikely. The probability of being attacked by infectious diseases regarded as dangerous is deemed negligible.
A large group of school-children 6-10 years of age were checked for their immunization status and by questionnaire for their parent's attitude to vaccinations. Children of higher socio-economic status have better immunization protection. In spite of pretended high motivation, people from Southern countries have a significantly smaller percentage of immunized children than Swiss people. This is probably caused by insufficient information.
To learn about parent, nurse, and family physician attitudes toward multiple simultaneous childhood vaccinations.
Survey.
Thirty-two family practice clinics in Minnesota.
Forty-six volunteer Minnesota Academy of Family Physicians Research Network members, 42 of their nurses, and 342 parents of their patients aged less than 6 years who have had at least one injection.
Number of injections believed to be too many for a child to receive simultaneously and comfort level associated with children's receiving three simultaneous injectable vaccinations.
Most parents, nurses, and physicians (71%, 76%, and 59%, respectively) think that three injections are too many for a child to receive at one visit. Similar percentages of parents, nurses, and physicians are uncomfortable with a child's receiving three injections at one visit. Sixty-seven percent of the physicians who do not offer universal newborn hepatitis B vaccinations cite the number of required simultaneous injections as a factor in that decision. Only 15% of physicians order all three recommended injections for most of their 15-month-old patients.
Most parents, nurses, and physicians are uncomfortable with three simultaneous injections for children. This discomfort may be a significant barrier to the adoption of the new immunization recommendations. The development of effective combination vaccines should be a research priority.
Measles is the most transmissible disease known to man. During the 1980s, the number of measles cases in the United States rose dramatically. Surprisingly, 20% to 40% of these cases occurred in persons who had been appropriately immunized against measles. In response, the United States adopted a two-dose universal measles immunization program. We critically examine the effect of vaccine failure in measles occurring in immunized persons.
We performed a computerized bibliographic literature search (National Library of Medicine) for all English-language articles dealing with measles outbreaks. We limited our search to reports of US and Canadian school-based outbreaks of measles, and we spoke with experts to get estimates of vaccine failure rates. In addition, we devised a hypothetical model of a school where measles immunization rates could be varied, vaccine failure rates could be calculated, and the percentage of measles cases occurring in immunized students could be determined.
We found 18 reports of measles outbreaks in very highly immunized school populations where 71% to 99.8% of students were immunized against measles. Despite these high rates of immunization, 30% to 100% (mean, 77%) of all measles cases in these outbreaks occurred in previously immunized students. In our hypothetical school model, after more than 95% of schoolchildren are immunized against measles, the majority of measles cases occur in appropriately immunized children.
The apparent paradox is that as measles immunization rates rise to high levels in a population, measles becomes a disease of immunized persons. Because of the failure rate of the vaccine and the unique transmissibility of the measles virus, the currently available measles vaccine, used in a single-dose strategy, is unlikely to completely eliminate measles. The long-term success of a two-dose strategy to eliminate measles remains to be determined.
To describe how parents actually use federally mandated vaccine information pamphlets and to evaluate the pamphlets' effects on parents' opinions about vaccination.
A controlled trial of vaccine information pamphlets based on a survey mailed to parents who either received (n = 140) or did not receive (n = 167) the pamphlets.
Parents of infants aged 2 to 8 months in a suburban, mainly upper-middle class private group practice in northern California.
More than 90% of parents believed that they had enough information to decide whether their child should be vaccinated, even among those who did not receive the pamphlets. Among parents who received the pamphlets, fewer than half (38%) read them thoroughly, and most (63%) said that they should be distributed only on the first visit for vaccinations. Parents who received the pamphlets did not differ from those who did not in terms of the proportions who would have liked more time to be spent discussing vaccines (34% vs 34%) or who were anxious about how the diphtheria and tetanus toxoids and pertussis vaccine would affect their child (60% vs 52%).
Vaccine information pamphlets, when used as an adjunct to discussions with physicians and nurses, have little effect on the opinions of well-educated parents. Future research and policy changes might focus on how to make the contents of the pamphlets less frightening and on allowing greater flexibility in how they are distributed.
Public health analyses suggest that, in spite of the possibility that pertussis vaccine may cause rare cases of neurological injury, catastrophic risks to individual children are lower if they are vaccinated. A number of parents, however, choose not to vaccinate their children. The purpose of this study was to investigate the decision processes of some parents who choose to vaccinate and some parents who choose not to do so. Surveys were mailed to 500 randomly selected subscribers of Mothering magazine. Two hundred and ninety-four completed questionnaires were returned (59%). In addition to well-recognized factors in vaccination decisions, perceived dangers of the vaccine, and of the disease and susceptibility to the disease, several cognitive processes not previously considered in vaccination decision studies were found to be important predictors in this population of parents: perceived ability to control children's susceptibility to the disease and the outcome of the disease; ambiguity or doubts about the reliability of vaccine information; a preference for errors of omission over errors of commission; and recognition that if many other children are vaccinated, the risk to unvaccinated children may be lowered. Although perhaps most cases of undervaccination for pertussis reflect more general problems of health care access, some parents choose to forego vaccination for their children for other reasons. Traditional risk-benefit arguments alone will be unlikely to persuade these parents to reassess their decisions. Efforts to increase childhood vaccination must incorporate an understanding of the cognitive processes that help drive these decisions.
As part of a larger hepatitis B vaccination program in San Francisco, hepatitis B vaccine is offered to seventh-grade students in selected middle schools. We investigated attitudes and beliefs about hepatitis B, hepatitis B vaccine, and school-based vaccination among parents of eligible students.
A survey was conducted of random samples of parents who consented, refused, or did not respond to a request for vaccination consent.
A larger proportion of persons who signed a vaccination consent or refusal form were biological parents and were Asian or white than parents who did not return a signed form. The most common reason for refusing vaccination, given by 84% of refusing parents, was that their children had already been vaccinated against hepatitis B. These parents recognized the severity and duration of hepatitis B virus infection as much as parents consenting to vaccination. About one third of parents who refused vaccination did not agree that schools were good places to vaccinate children. Overall, 116 parents (40%) consulted someone before deciding to consent or refuse; 95 (33%) spoke with a health professional. Most parents not returning signed consent or refusal forms reported that they never received forms from their children or that they returned signed forms to their children, who never delivered them to school.
Most parents accepted school-based vaccination, and obtaining parental consent for school-based vaccination was possible. Nonetheless, new approaches may be needed for those students and parents who do not comply with the consent process.
The purpose of this study was to analyze the attitude and grade of knowledge of the parents of children concerning the vaccination of their children, as well as to know their opinion about a program destine to diminish their anxiety.
The subjects of the study were parents of children of our county that began their immunizations in 1994. The method utilized was realization of a survey with closed questions. The statistical analysis was carried out by means of the R-SIGMA program.
There were 115 surveys registered. Of these 71% has adequate knowledge of the illness against which their child had been vaccinated. Anxiety and fear was seen in 60% before beginning the vaccination process, descending to 30% once the process of immunization began. Only 54.5% perceived the vaccination as inoffensive and 66% considered that the illness against which their child was being protected were very grave. The principal secondary effect seen in the children was fever (70.4%). Forty-one percent of those surveyed considered that the illness of the vaccination program were typical of a low socioeconomic class. Only 7% gave an opinion that the vaccine should be voluntary and in 100% of the cases was it considered that it was an advance in medicine. Only 25% of the population surveyed had access to previous information and their attitude was reinforced positively. The data most valued by those surveyed, referring to the vaccination program, was the informative interview previous to the program and the presence of the pediatrician.
The vaccine is considered as something dangerous, but necessary. Better education of the parents, on the part of the sanitary authorities and those responsible of ordering and administering vaccines, would result in a modification in the attitude of the population in regards to vaccinations.
We investigated a consecutive series of children with chronic enterocolitis and regressive developmental disorder.
12 children (mean age 6 years [range 3-10], 11 boys) were referred to a paediatric gastroenterology unit with a history of normal development followed by loss of acquired skills, including language, together with diarrhoea and abdominal pain. Children underwent gastroenterological, neurological, and developmental assessment and review of developmental records. Ileocolonoscopy and biopsy sampling, magnetic-resonance imaging (MRI), electroencephalography (EEG), and lumbar puncture were done under sedation. Barium follow-through radiography was done where possible. Biochemical, haematological, and immunological profiles were examined.
Onset of behavioural symptoms was associated, by the parents, with measles, mumps, and rubella vaccination in eight of the 12 children, with measles infection in one child, and otitis media in another. All 12 children had intestinal abnormalities, ranging from lymphoid nodular hyperplasia to aphthoid ulceration. Histology showed patchy chronic inflammation in the colon in 11 children and reactive ileal lymphoid hyperplasia in seven, but no granulomas. Behavioural disorders included autism (nine), disintegrative psychosis (one), and possible postviral or vaccinal encephalitis (two). There were no focal neurological abnormalities and MRI and EEG tests were normal. Abnormal laboratory results were significantly raised urinary methylmalonic acid compared with age-matched controls (p=0.003), low haemoglobin in four children, and a low serum IgA in four children.
We identified associated gastrointestinal disease and developmental regression in a group of previously normal children, which was generally associated in time with possible environmental triggers.
In summary, I have addressed 5 key issues concerning vaccines today. First is the essentially empiric nature of vaccinology. Vaccinology is not a rational science. Each idea must be tested by experiment. This need for trial and error experimentation is a substantial barrier to new vaccines. The proven track record of existing vaccines to eradicate disease, to reduce occurrence of disease, reduce human suffering and contain health care spending--when coupled with the potential for new discoveries against significant disease targets--is unparalleled by other therapeutic areas. The complexity of vaccine delivery today in clinical practice with 15-17 injections in the first two years of life emphasizes the need for development of combination pediatric vaccines, for example, putting DTaP, HBV, HIB, and IPV together. This has proved to be far more difficult than previously believed due to unpredicted immune interference and incompatibilities on mixing of different components, demonstrating again the inadequacy of our understanding of how vaccines work and the empiric nature of the science. Similar complexity will face adult vaccines in the future, as new adult vaccines are developed. Next, vaccines remain undervalued by people, by government, and by society. Government-controlled prices in many areas of the world prohibit a return on investment that supports innovative R&D. New vaccines may be unavailable in certain markets because of pricing restraints. Prices of new vaccines in the developed world will rise as will prices in the developing world for products currently available only in the developed world. Reluctance to use vaccines is an especially disturbing symptom of the undervaluation issue. In the U.S., school entry requirements have kept childhood immunization rates high by five years of age. But this is a new phenomenon, driven in part by the measles outbreaks. The risk is that history will repeat itself. In the absence of disease and lack of public knowledge of these diseases, complacency sets in, immunization rates fall, with the expected result on occurrence of disease. For adults, we may hope that managed care with its interest in cost saving and disease prevention may actually help in achieving the goals of the Year 2000. Finally, I have talked about the anti-vaccine attitudes and forces that impede control of disease by vaccines. It is important that new initiatives be undertaken that will be successful in providing a balanced view of vaccine safety, efficacy and benefits to the public, to the provider and to the payers.
The study examined beliefs and attitudes towards pertussis (and other) vaccinations in three groups of caregivers; those who had fully vaccinated a target child against pertussis (FV; n = 85), those whose child partially completed the course (PV; n = 70) and those who refused to have their child receive the pertussis vaccination (NV; n = 73). The NV group reported significantly more concern over long-term health problems as a result of pertussis vaccination, a lower risk of catching pertussis if not immunized and attached a lower importance to pertussis vaccination than either of the other two. They also rated their child as more likely to develop pertussis if immunized than those in the FV group. The NV group also reported a greater risk perception for some other vaccinations (e.g. mumps, rubella and measles) than the other groups. The implications for health education are discussed.
Epidemiological evidence indicates infants immunised against diphtheria, pertussis and tetanus (DPT) are at decreased risk of sudden infant death syndrome (SIDS). Asymptomatic whooping cough and pyrogenic toxins of Staphylococcus aureus have been implicated in the aetiology of SIDS. The objectives of the present study were: (1) to determine if the DPT vaccine induced antibodies cross-reactive with the staphylococcal toxins; (2) to determine if antibodies to the pertussis toxin (PT) and the staphylococcal toxins were present in the sera of women during late pregnancy; (3) to examine the effects of infant immunisation on levels of antibodies to PT and the staphylococcal toxins; (4) to assess the effects of changes in immunisation schedules in the UK on the incidence and age distribution of SIDS. Enzyme-linked immunosorbent assays (ELISA) were used to measure binding of rabbit or human IgG to the DPT vaccine, PT, toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins A (SEA), B (SEB) and C (SEC). Neutralisation activity of anti-DPT serum was assessed by a bioassay for induction of nitric oxide from human monocytes by the staphylococcal toxins. Anti-DPT serum bound to the DPT vaccine, PT and each of the staphylococcal toxins. It also reduced the ability of the four toxins to induce nitric oxide from monocytes. In pregnant women, levels of IgG to PT, SEC and TSST-1 decreased significantly in relation to increasing weeks of gestation while antibodies to SEA and SEB increased. In infants' sera there were significant correlations between levels of IgG bound to DPT and IgG bound to PT, TSST-1 and SEC but not SEA or SEB. Antibody levels to the toxins in infants declined with age; sera from infants < or = 2 months of age had higher levels of IgG bound to the toxins than those older than 2 months. This pattern was observed for infants whose immunisation schedules began at 2 months of age or 3 months of age. The decrease in IgG bound to the toxins was, however, less for those immunised at 2 months. The decrease in SIDS deaths after the change in immunisation schedules was greatest in the 4-6-month age range. While DPT immunisation might prevent some unexplained infant deaths due to asymptomatic whooping cough, these data indicate that immunisation with DPT also induces antibodies cross-reactive with pyrogenic staphylococcal toxins implicated in many cases of SIDS. Passive immunisation of infants who have low levels of these antibodies might reduce further the numbers of these infant deaths.
Nearly 20 years afer the licensure of a vaccine against the hepatitis B virus, an estimated 300,000 U.S. residents still become infected with the potentially fatal liver virus every year. One major reason for the persistence of hepatitis B is that few adolescents and adults whose sexual and drug-using behavior places them in danger of infection are able to obtain the vaccine. Public health authorities and legislators have spent hundreds of millions of dollars to vaccinate low-risk but politically popular babies, while largely ignoring high-risk older siblings, parents, aunts, and uncles. Now this strategy, chosen in part for political reasons, is unwittingly fueling anti-vaccine efforts. The United States' poor use of the hepatitis B vaccine will surely cast a shadow over efforts to prevent HIV, a disease with remarkably similar transmission patterns.
To determine whether DTPP+Hib vaccination (diphtheria, tetanus, pertussis, poliomyelitis +/- haemophilus) increased the risk of sudden unexpected death (SUD) in children under 3 months of age.
We conducted a multicentre case-control study in the 28 French 'SIDS Centers'. Case selection was based on death labelled sudden infant death syndrome (SIDS) of an infant aged between 30 and 90 days. Three living controls were selected, matched for sex, gestational age and born immediately after the victim in the same maternity unit.
We identified 114 cases of SUD aged between 30 and 90 days and 341 live controls matched for age and sex and born in the same maternity unit as the case. DTPP+/-Hib immunization did not increase the risk of SUD (OR 1.08) (95% CI 0.49, 2.36) in children under 3 months of age when adjusted for sleeping position, illness in the week before death, maternal tobacco consumption, birth weight, type of mattress, breastfeeding and sex. However, low birth-weight (6.53 [2.29, 18.9]), multiple birth (5.1 [1.76, 15.13]), no breastfeeding (1.77 [1.1, 2.85]), prone sleeping position (9.8 [5, 8, 18, 9]), soft mattress (3.26 [1.69, 6.29]), recent illness (3.44 [1.84, 6.41]) and parental smoking (1.74 [1.2, 2.96]) were confirmed as risk factors in early SIDS.
DTPP+/-Hib immunization is not a risk factor for early SUD. In this population, we found the same risk factors as described for SIDS.
To determine the impact of the American Academy of Pediatrics/US Public Health Service (AAP/USPHS) joint statement on thimerosal in vaccines on hospital infant hepatitis B vaccination policies in Wisconsin.
The nurse managers of hospital newborn nurseries (n = 110) were surveyed by mail. Nonresponders were resurveyed. Twelve hospitals no longer provided obstetric services. Of the remaining 98 hospitals, 84 (86%) responded to the initial mailing and 14 (14%) responded to the second mailing. The number of hospitals that offered hepatitis B vaccine to infants before July 1999 was compared with that in March 2000. The number of hospitals that had policies in place to vaccinate infants whose mothers' hepatitis B surface antigen status (HBsAg) was positive or unknown during the thimerosal alert (July 1999 through November 1999) was compared with that in March 2000.
Before July 1999, 81% of the hospitals representing 84% of reported Wisconsin births routinely offered hepatitis B vaccine to all infants. By March 2000, 50% of hospitals, representing 43% of births, had resumed routine infant hepatitis B vaccination. Physician decision to use a combination Haemophilus influenzae type b hepatitis B vaccine was the most frequently given reason for not reinstituting infant hepatitis B vaccination. During the thimerosal alert, 23% of hospitals did not have policies to vaccinate infants whose mothers were HBsAg-positive and 51% did not have policies to vaccinate infants whose mothers' HBsAg status was unknown. By March 2000, 6% of hospitals still did not have policies to vaccinate infants whose mothers were HBsAg-positive and 24% did not have policies to vaccinate infants whose mothers' HBsAg status was unknown.
The AAP/USPHS joint statement on thimerosal in vaccines has resulted in a 38% decrease in the number of hospitals routinely offering infants hepatitis B vaccine. Although thimerosal-free hepatitis B vaccine is now available, some hospitals still do not have appropriate policies in place for vaccinating infants whose mothers' HBsAg status is positive or unknown. In the future, policymakers should include anticipated consequences that may result from changes in immunization policy in their recommendations.
We describe neonatal hepatitis B virus (HBV) vaccine policies in Colorado before and after thimerosal recommendations, plans for use of thimerosal-free HBV vaccine, and nurses' awareness of high-risk criteria for HBV vaccination. The results suggest that fewer neonates are receiving HBV vaccine at birth hospitals.
To identify correlates of hepatitis B vaccination status in sixth-grade students in the year prior to implementation of a requirement mandating immunization for seventh-grade entry.
A survey of parents of sixth-graders in 5 schools in San Diego County. Two logistic regression models were tested to predict the outcome varia