Psychological mechanisms and interventions directed at vaccination attitudes

Introduction

Vaccines are widely considered the product of modern medicine preventing infectious diseases from remaining prevalent in society (Hodson, 2019). The modern scientific pursuit of vaccines is first documented in the 1700s (Riedel, 2005). Government-initiated mass vaccination started in 1840 with the United Kingdom's Vaccination Act (Wolfe and Sharp, 2002). Since then, the implementation of vaccines has resulted in deadly diseases, such as measles and whooping cough, becoming rare and a complete worldwide eradication of smallpox (Asturias et al., 2016; National Center for Immunization and Respiratory Diseases, 2020). Implementation of vaccines facilitated not only the immunization of the vaccinated individual but also that of those around them. Herd immunity is a biological and physical phenomenon in society for which a threshold level of individuals has been immunized, facilitating a significant decrease in the disease transmission rate (Berezin and Eads, 2016). This indicates that individual vaccination is a personal choice of societal concern on a global scale. It should be noted, however, that herd immunity is sometimes very difficult to attain, due to waning immunity, or pathogen mutability, and it is unobtainable for diseases that are not spread from person to person, including tetanus (Fine, 1993).

Vaccines are a preventative measure usually administered to healthy individuals and, as such, are held to a high standard of safety (Asturias et al., 2016). However, the widespread use of vaccines has led to concerns over their safety in recent decades (Asturias et al., 2016). A potential risk of immunization is a vaccine's side effect profile, an effect produced in the body separate from the vaccine's intended effect (Health and Human Services, 2021). Common side effects of most vaccines are usually mild and go away without intervention and can include pain or swelling at the injection site, mild fever, chills, fatigue, headache, muscle or joint aches, and fainting (Health and Human Services, 2021). While these side effects are unpleasant, they indicate that the body's immune system is beginning to recognize and build a defense against that disease (Health and Human Services, 2021). A severe side effect is anaphylaxis, which is, however, extremely rare. The U.S. Department of Health and Human Services (2021) reports the incidences of severe allergic reactions to be 1–2 people per million doses.

In addition to the side effects, the literature reports that in rare cases, adverse events following immunization (AEFI) occur largely unrelated to the vaccine itself (Asturias et al., 2016; Okuhara et al., 2020). Asturias et al. (2016) acknowledge that the misunderstanding about these reactions and false literature has led to the misattribution of side effects and AEFI and subsequent negative public opinions.

Anti-vaccination movement

There are numerous broad definitions in the literature on vaccine hesitancy and refusal, depending on the nature of their investigation into the underlying mechanisms of the behavior. However, for this review, vaccine hesitancy is defined as a delay in acceptance or refusal of vaccines, despite the availability of vaccination services (Peretti-Watel et al., 2015). There are those who are hesitant about vaccines but still partake in the immunizations; however, there are also those who are actively objecting to the use of vaccines and subsequently do not partake in immunizations (Salmon et al., 2015; Asturias et al., 2016; Bocquier et al., 2018; Wiley et al., 2020). The latter are categorized as refusers and are the focus of the current review (Salmon et al., 2015; Asturias et al., 2016).

With the scientific discovery of vaccines came the politics of government decision-making, and with it, counter-movements, known as anti-vaccination activists (Nour, 2019). The motive behind these movements was to fight against the compulsory nature of vaccinations holding the view that this was a violation of individual liberties rather than opposition to vaccines themselves (Nour, 2019).

The health belief model (HBM) is a theoretical model employed to guide health promotion and disease prevention programs (Nour, 2019). It is used to explain and predict individual changes in health behaviors, and it argues that “the two components of health-related behavior are (1) the desire to avoid illness, or conversely get well if already ill; and, (2) the belief that a specific health action will prevent, or cure, illness” (Boston University School of Public Health, 2022, “The Health Belief Model” section). The model illustrates the risk–benefit analysis in that an individual would analyze the danger of developing the sickness and the value of behaving to offset this risk (Nour, 2019). When applied to vaccines, it describes and predicts how people evaluate the risk of susceptibility to a disease that a vaccine protects against the danger connected with the sickness and the hazards associated with the vaccine (Nour, 2019). Aligned with the HBM are the theory of planned behavior (TPB) and the social cognitive theory (SCT) (Nour, 2019). The TPB outlines that intentions and perceived control influence decisions to engage in a particular behavior. The SCT proposes that goals, outcome expectancies, self-efficacy, and sociostructural variables influence an individual's behavior (Nour, 2019). It is essential to investigate these variables, as these are where interventions could be targeted.

Strategies addressing vaccine attitudes

Anderson et al. (2020) highlight that the current strategies provided to physicians by the Center for Disease Control in the U.S. facilitating vaccine-refusing families' informed decision-making are an empathic approach. However, the downsides of this approach are the time it takes to convey empathy effectively and build trust, which is an expensive resource in clinical settings. Furthermore, having vaccine-resistant individuals in clinical settings exposes vulnerable patients and staff to vaccine-preventable diseases (Anderson et al., 2020).

Much of the literature addressing vaccine refusal includes removing barriers, such as access to vaccines and affordability (Anderson et al., 2020). Some governments have been guided by this research, such as Australia's implementation of pharmacists administering vaccines to increase access (National Centre for Immunisation Research and Surveillance, 2021). This targets an environmental factor identified as a barrier to access; however, this approach does not address the underlying psychological mechanisms. In their systematic review of strategies to address parents' refusal of childhood vaccinations, Nour (2019) identified mass marketing and direct communication as two strategies proposed in the literature. Mass marketing aimed to counteract the misinformation spreading, while direct communication was in line with the CDC recommendations that healthcare professionals build a relationship of trust (Nour, 2019).

This review aims to identify the underlying psychological mechanisms of individuals against vaccinations and the interventions designed to target those to improve vaccination uptake. It is important to note that the review of interventions is not aimed to override individual autonomy but rather balance autonomy with unhelpful psychological underpinnings and facilitate a more thorough understanding and compassion (Rozbroj et al., 2019b). There is currently a gap in the literature outlining the state of the research to date and the success of current interventions. Specific research questions for this review include.

• What underlying mechanisms drive vaccination-refusing movements and individual thoughts and behaviors?

• What are the current interventions targeting these mechanisms, and how effective are they?

Method

Search strategy

A systematic search, selection, and review of the existing literature were conducted concerning vaccination-refusing typologies and intervention strategies. The current review was guided by, and the results are written following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA; Page et al., 2021). Relevant articles from the following databases were searched: Cochrane, PubMed, PsychInfo (Ovid), and ProQuest between May and September 2021. The following terms were utilized, individually and in combination, in the search: “anti-vaxxers,” “anti-vaccination,” “vaccine refusal,” “vaccine hesitancy,” “psychological determinants AND anti-vaxxers,” “personality traits AND anti-vaxxers,” “immunization theories AND vaccine refusal,” “increasing vaccination OR vaccine uptake,” “vaccine literacy,” “anti-vaxxer AND interventions,” “interventions vaccine hesitancy AND vaccine refusal,” “vaccine refusal AND anxiety OR fear,” “vaccine refusal OR hesitancy AND attitudes OR beliefs,” and “vaccine refusal AND health anxiety.” It is important to note that while hesitancy was not the focus of the study, the literature is mixed on the definition of hesitancy and refusal; therefore, to encapsulate the research as a whole, hesitancy was included as a search term and the exclusion criteria were applied at the study selection step. The searches were limited to English texts and peer-reviewed, published articles only. Subsequently, reference lists were also searched for relevant records.

Study selection and data extraction

Study selection

Following PRISMA, the Cochrane “PICO” method was utilized to refine eligibility criteria for the inclusion of studies in the current review (Page et al., 2021; McKenzie et al., 2022). PICO defines criteria surrounding population, intervention, comparator, and outcome for studies investigating interventions (McKenzie et al., 2022). The scope of these parameters can be broad or narrow depending on the research question (McKenzie et al., 2022). In the present review, the population parameter included individuals with anti-vaccination beliefs or behaviors. The intervention parameter was broad, given the explanatory nature of our review, and included all empirical-design studies. Similarly, no parameters were set for the comparator or outcome parameters, which is a common approach for exploratory reviews (McKenzie et al., 2022). Furthermore, no limitations were applied to age, geographical location, or type of vaccination.

The PRISMA protocol recommends additional parameters regarding research design, language, and publication status (Page et al., 2021). The design parameter included specific measures or questions identifying psychological underpinnings of anti-vaccination beliefs or behaviors, excluding studies with a limited focus on prevalence and sociodemographic factors. As stated previously, the search was limited to English text only and peer-reviewed published articles. Subsequently, titles and abstracts were evaluated for relevance, regarding the target population (i.e., individuals with anti-vaccination beliefs or behaviors) and design (i.e., empirical studies), and duplicates were removed. Subsequently, the remaining records underwent full-text screening and were subjected to a research quality appraisal conducted following the Mixed Methods Appraisal Tool (MMAT) (Hong et al., 2018).

The MMAT is a tool designed to facilitate the appraisal of research for review studies based on methodological quality (Hong et al., 2018). First, studies were excluded if the research question was unclear, or the data did not address the research question. Second, studies were examined regarding the appropriateness of data collection methods and measures, representativeness of samples, risk of bias, and appropriateness of the statistical analysis. Specifically, studies were deemed low quality and excluded if they were not relevant to the scope of the study, did not represent the target population (e.g., focus on hesitancy without refusal), focused solely on barriers to vaccination (e.g., access to vaccinations), were theoretical only, did not define data collection methods (e.g., no specific measures/questions identifying anti-vaccination attitudes), or were statistically underpowered (i.e., with very small sample sizes or effect size). Figure 1 demonstrates the selection process.

FIGURE 1

Figure 1. Study selection.

Data extraction

The extracted data included the year of publication, authors, population demographics, methodology, variables, outcomes, strengths, and limitations (including the quality of the study).

Results

Study selection

A total of 1,897 records were retrieved via the search strategy outlined previously. Subsequent title and abstract screening resulted in 1,617 records being excluded from the present review. From the remaining 280 records, 241 were excluded after a full-text screening, with exclusion criteria concerning study quality (utilizing the MMAT), relevance to anti-vaccination, underlying mechanisms, or interventions. Therefore, a total of 39 studies were included in the current review.

Study characteristics

All studies included in the review were conducted between 2004 and 2021. The number of studies investigating the underlying mechanisms of anti-vaccination attitudes and beliefs was 33 (Smith et al., 2004; Fowler et al., 2006; Luyten et al., 2014; Michael et al., 2014; Wada and Smith, 2015; Reich, 2016; Amin et al., 2017; Chung et al., 2017; Bryden et al., 2018; Carrion, 2018; Hornsey et al., 2018; Motta et al., 2018, 2021; Restivo et al., 2018; Tustin et al., 2018; Bianco et al., 2019; Carpiano et al., 2019; Helps et al., 2019; Romijnders et al., 2019; Rossen et al., 2019; Rozbroj et al., 2019a, 2020, 2022; Cadeddu et al., 2020; Goldberg and Richey, 2020; Tomljenovic et al., 2020; Dzieciolowska et al., 2021; Elkalmi et al., 2021; Freeman et al., 2021; Huynh and Senger, 2021; Martinez-Berman et al., 2021; Murphy et al., 2021). Within this subset of studies, 12 studies investigated parents as a sample (Smith et al., 2004; Reich, 2016; Amin et al., 2017; Chung et al., 2017; Carrion, 2018; Tustin et al., 2018; Bianco et al., 2019; Carpiano et al., 2019; Helps et al., 2019; Romijnders et al., 2019; Rossen et al., 2019; Tomljenovic et al., 2020), 20 adults as a sample (Fowler et al., 2006; Luyten et al., 2014; Michael et al., 2014; Wada and Smith, 2015; Bryden et al., 2018; Hornsey et al., 2018; Motta et al., 2018, 2021; Restivo et al., 2018; Rozbroj et al., 2019a, 2020, 2022; Cadeddu et al., 2020; Goldberg and Richey, 2020; Dzieciolowska et al., 2021; Elkalmi et al., 2021; Freeman et al., 2021; Huynh and Senger, 2021; Murphy et al., 2021), and one was web based (Martinez-Berman et al., 2021).

The number of studies investigating the efficacy of interventions targeting this population was six (Dempsey et al., 2015; Pot et al., 2017; Gagneur et al., 2018; Lemaitre et al., 2019; Pluviano et al., 2019; Nowak et al., 2020). Of this, five were investigating parents of children who require vaccinations (Dempsey et al., 2015; Pot et al., 2017; Gagneur et al., 2018; Lemaitre et al., 2019; Pluviano et al., 2019), and one focused on the general adult population (Nowak et al., 2020).

Of all studies, eight utilized empirically validated measures (Amin et al., 2017; Bryden et al., 2018; Hornsey et al., 2018; Bianco et al., 2019; Freeman et al., 2021; Huynh and Senger, 2021; Martinez-Berman et al., 2021; Murphy et al., 2021), while the remaining studies utilized semi-structured interviews, surveys, and questionnaires designed specifically for the study, and web-based data mining.

Table 1 displays the characteristics of the studies included, including aims, study design, intervention/measures, outcomes, and strengths and limitations.

TABLE 1

Table 1. Study characteristics.

Key findings

The studies investigating the underlying mechanisms of anti-vaccination attitudes and beliefs identified anti-vaccination attitudes to be related to lower levels of intellectual humility (Tomljenovic et al., 2020; Huynh and Senger, 2021) with the specific belief that the individual knows more than a medical professional (Motta et al., 2018). Nineteen studies identified beliefs associated with anti-vaccination attitudes, specifically distrust in the scientific community (Fowler et al., 2006; Carrion, 2018; Helps et al., 2019; Romijnders et al., 2019; Cadeddu et al., 2020; Motta et al., 2021), distrust in pharmaceuticals (Bianco et al., 2019; Rozbroj et al., 2019a, 2020; Dzieciolowska et al., 2021; Martinez-Berman et al., 2021), superstitious beliefs (Bryden et al., 2018), and belief in conspiracy theories (Hornsey et al., 2018; Smith and Graham, 2019; Goldberg and Richey, 2020; Tomljenovic et al., 2020; Martinez-Berman et al., 2021; Rozbroj et al., 2022). Four studies highlighted a moral profile inclusive of increased liberty (Luyten et al., 2014; Amin et al., 2017; Hornsey et al., 2018; Rossen et al., 2019); harm, purity, and decreased moral preference for those in authority (Rossen et al., 2019).

Additionally identified as being associated with anti-vaccination profiles were celebrity admiration (Martinez-Berman et al., 2021), religiosity (Michael et al., 2014; Rozbroj et al., 2019a; Elkalmi et al., 2021), reactance (Hornsey et al., 2018), belief in natural immunity and purity of the body (Michael et al., 2014; Reich, 2016), fear or disgust of blood needles (Hornsey et al., 2018; Freeman et al., 2021), belief as social identity (Motta et al., 2021), and low participation in political or cultural life (Cadeddu et al., 2020). Typical behaviors identified in the literature were that those that held anti-vaccination attitudes were more likely to search the internet or other sources of information rather than seek information from government or health professionals (Smith et al., 2004; Wada and Smith, 2015; Chung et al., 2017; Tustin et al., 2018; Murphy et al., 2021).

The studies examining specific interventions focused on motivational interviewing, tailored web-based interventions, and education (Dempsey et al., 2015; Pot et al., 2017; Gagneur et al., 2018; Lemaitre et al., 2019; Pluviano et al., 2019; Nowak et al., 2020). Two studies investigated the utility of motivational interviewing-based strategies, with both studies reporting significant increases in vaccine uptake (Gagneur et al., 2018; Lemaitre et al., 2019). Two other studies explored the benefit of interactive-/web-based tailored messaging, with both studies reporting no significant impact (Dempsey et al., 2015; Pot et al., 2017). The final two studies examined the efficacy of education-based interventions, both resulting in no significant impacts (Pluviano et al., 2019; Nowak et al., 2020).

Discussion

The current review aimed to identify the underlying psychological mechanisms of individuals holding anti-vaccination attitudes and the interventions designed to target these mechanisms. Our review addresses a gap in the literature by increasing the understanding of individuals with anti-vaccination beliefs and behaviors. Furthermore, our findings help to clarify the roles of health professionals in assisting with vaccine decision-making that balances individual rights with societal demands. Studies were included based on the relevance (specific focus on vaccine refusal and underlying mechanisms) and quality of the research, with a total of 39 studies, 33 on underlying mechanisms, and six investigating interventions. The literature included in this review identified three core domains underlying the psychological mechanisms related to anti-vaccination attitudes, including beliefs, morals, and individual characteristics.

Beliefs

The overarching beliefs discovered primarily included a distrust of the scientific community and pharmaceuticals, and the presence of superstitious and conspiratorial beliefs (Smith et al., 2004; Fowler et al., 2006; Wada and Smith, 2015; Chung et al., 2017; Carrion, 2018; Hornsey et al., 2018; Tustin et al., 2018; Bianco et al., 2019; Helps et al., 2019; Romijnders et al., 2019; Smith and Graham, 2019; Cadeddu et al., 2020; Tomljenovic et al., 2020; Dzieciolowska et al., 2021; Martinez-Berman et al., 2021; Motta et al., 2021; Murphy et al., 2021; Rozbroj et al., 2022). This finding is congruent with previous research exploring linguistic themes among social media users expressing anti-vaccination beliefs (Buchanan and Beckett, 2014; Faasse et al., 2016; Okuhara et al., 2017, 2018; Smith and Graham, 2019; Dhaliwal and Mannion, 2020). Returning to the health belief model, this mistrust of vaccines and science directly impacts risk-reward decision-making processes, as the information involved in the decision-making process may not reflect validated science or health information.

Morals

Results from the literature outline a moral profile that may typically be observed in an individual holding anti-vaccination attitudes. This moral profile includes a higher preference for morals associated with liberty, harm, and purity, with decreased moral preferences for authority (Luyten et al., 2014; Amin et al., 2017; Hornsey et al., 2018; Rossen et al., 2019). Liberty underpins attitudes surrounding rights and autonomy associated with mandated vaccinations and an individual's right to personal choices (Rossen et al., 2019). This moral preference aligns with their beliefs surrounding mistrust and the findings that typical behaviors included sourcing other avenues of information, such as celebrities, and socially aligning with others who think the same (Smith et al., 2004; Wada and Smith, 2015; Chung et al., 2017; Tustin et al., 2018; Martinez-Berman et al., 2021; Motta et al., 2021; Murphy et al., 2021). In addition, a high moral value for liberty suggests that mandates surrounding vaccines may only further exacerbate their beliefs, increase the gap between science and the community, and increase the utility of motivational interviewing as an effective tool (Kriss et al., 2022). Morals related to harm are associated with heightened attention to the detriment that may be caused through vaccines, consistent with the literature that highlights cognitions related to the risk of side effects and adverse reactions (Amin et al., 2017; Carrion, 2018; Carpiano et al., 2019; Helps et al., 2019; Rossen et al., 2019; Elkalmi et al., 2021). Morals related to purity suggest that these individuals have a deep belief in natural immunity, indicating that when conducting a risk analysis in their decision-making, the benefits associated with not vaccinating appear higher than the risks of vaccination (Rossen et al., 2019). In addition, there was a decreased moral preference for authority, suggesting a lack of support when health directives are provided and mandated (Luyten et al., 2014; Rossen et al., 2019).

Individual differences

Two main cognitive biases were identified underpinning anti-vaccination attitudes in the research presented in this review. Motta et al. (2018) found a correlation between the Dunning–Kruger effect and anti-vaccination attitudes, indicating that those who hold anti-vaccination attitudes have overconfidence in their knowledge. This is consistent with Aechtner's (2021) study, which examined anti-vaccine websites and discovered that commentators typically believe their expertise to be superior to medical specialists. This is further congruent with other research suggesting a mistrust of the scientific community, lower likelihood to obtain information from scientific sources, discounting scientific findings, and Huynh and Senger's (2021) finding of low intellectual humility (Fowler et al., 2006; Bryden et al., 2018; Bianco et al., 2019; Rozbroj et al., 2019a; Motta et al., 2021; Murphy et al., 2021). In addition, the omission bias was identified across multiple studies (Fowler et al., 2006; Luyten et al., 2014; Michael et al., 2014; Amin et al., 2017; Hornsey et al., 2018; Rossen et al., 2019). This indicates that some individuals holding anti-vaccination attitudes engage in risk-reward decision-making from the view that omission of action (not vaccinating) is less risky than engaging in action (vaccination) (Freeman et al., 2021). This bias is congruent with the moral profile inclusive of purity, highlighting a preference for natural immunity and omission of action to decrease perceived risk. Understanding an individual's cognitive style, including cognitive biases, aids in understanding their decision-making, and how to assist to improve health and wellbeing while preserving autonomy.

Interestingly, the examined research found minimal difference between individual anti-vaccination attitudes and parent anti-vaccination attitudes, with mistrust in the scientific community and fear of adverse reactions or side effects serving as overarching themes supporting both opinions (Smith et al., 2004; Fowler et al., 2006; Wada and Smith, 2015; Chung et al., 2017; Carrion, 2018; Hornsey et al., 2018; Tustin et al., 2018; Bianco et al., 2019; Helps et al., 2019; Romijnders et al., 2019; Smith and Graham, 2019; Cadeddu et al., 2020; Tomljenovic et al., 2020; Dzieciolowska et al., 2021; Martinez-Berman et al., 2021; Motta et al., 2021; Murphy et al., 2021; Rozbroj et al., 2022). Regarding the fear of reactions and side effects, parents appeared to report more experience with adverse reactions (friends, family, or narratives); however, it must be noted that there was limited analysis into personal experience in any studies within the adult individuals group.

Interventions

The present literature highlights the promise of motivational interviewing as a technique for health professionals to decrease vaccine refusal based on individual decision-making (Gagneur et al., 2018; Lemaitre et al., 2019). Motivational interviewing increases autonomous motivation by facilitating collaboration and empathy and positioning the individual as the “expert” on their values. It has already been used successfully in the psychological field (e.g., treatment compliance) (Widder, 2017). In line with the health belief model, motivational interviewing facilitates long-term behavioral change by acting on the morals and beliefs of the individual, i.e., respecting their right to autonomy (Fall et al., 2018).

Interestingly, two studies highlighted a fear or disgust of blood needles among those who oppose vaccination (Hornsey et al., 2018; Freeman et al., 2021). This not only emphasizes an under-researched area within the study of psychological underpinnings of anti-vaccination attitudes but also presents another avenue in which psychological interventions, such as motivational interviewing, may assist individuals.

Interactive web-based messaging and education-based interventions were found to have less utility in facilitating change (Dempsey et al., 2015; Pot et al., 2017; Pluviano et al., 2019; Nowak et al., 2020). Congruent with previous findings suggesting a significant level of distrust of the scientific community and a propensity to seek out other sources of information, it is not surprising that education-based interventions do not impact individuals with anti-vaccination attitudes (Smith et al., 2004; Fowler et al., 2006; Wada and Smith, 2015; Chung et al., 2017; Carrion, 2018; Hornsey et al., 2018; Tustin et al., 2018; Bianco et al., 2019; Helps et al., 2019; Romijnders et al., 2019; Smith and Graham, 2019; Cadeddu et al., 2020; Tomljenovic et al., 2020; Dzieciolowska et al., 2021; Martinez-Berman et al., 2021; Motta et al., 2021; Murphy et al., 2021; Rozbroj et al., 2022).

Strengths, limitations, and future research

The strengths of the current research include the diversity of vaccines and populations studied in vaccination decision-making. Furthermore, the literature included a mixture of quantitative and qualitative methods facilitating a richer understanding. Finally, the strengths of the present review consist of the exclusion of poorer quality studies, and the dual focus on underlying mechanisms and target interventions to facilitate understanding of how the two are working together (or not).

The limitations of the current research include a lack of consistency in identifying anti-vaccination attitudes or vaccine refusals, the limited use of validated tools, the size of the target populations, and the western perspective (see Table 1 for specific studies). Within the literature, definitions of “anti-vaccination” included beliefs and behaviors ranging from entirely against vaccines and refusing uptake to viewpoints amenable to change. This inconsistency increased the difficulty of conducting the review and introduced a degree of subjectivity that the use of the MMAT tool usually decreases. In addition, only a few studies utilized validated tools to identify anti-vaccination attitudes, which could impact capturing the true nature of vaccine refusal. Future research into typologies could build upon the current research utilizing psychometrically validated tools, such as Shapiro's et al. (2018) Vaccine Hesitancy Scale.

Furthermore, it is important to highlight that intervention focused on individual attitudes is only one of the many ways in which vaccination uptake can be improved. Other important factors, such as access to and affordability of vaccines (Anderson et al., 2020), go beyond the scope of the current review.

Finally, only a few studies focused on anti-vaccination attitudes on a population level, meaning that the generalizability might be low. Similarly, the western perspective of the research with predominantly United States, Canadian, United Kingdom, and Australian-based studies also affects generalizability. This bias may be due to the limitation of the current literature review, in which only studies written in English were included. Future research should investigate other populations to gain a more holistic perspective on anti-vaccination beliefs, as it is a global issue.

Author contributions

SA and OB contributed to conception, design, and manuscript writing. All authors have read and approved the submitted version.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher's note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

References

Aechtner, T. (2021). Distrust, danger, and confidence: a content analysis of the Australian vaccination-risks network blog. Public Understand. Sci. 30, 16–35. doi: 10.1177/0963662520963258

PubMed Abstract | CrossRef Full Text | Google Scholar

Amin, A., Bednarczyk, R. A., Ray, C. E., Melchiori, K. J., Graham, J., Huntsinger, J. R., et al. (2017). Association of moral values with vaccine hesitancy. Nat. Hum. Behav. 1, 873–880. doi: 10.1038/s41562-017-0256-5

PubMed Abstract | CrossRef Full Text | Google Scholar

Anderson, M. G., Ballinger, E. A., Benjamin, D., Frenkel, L. D., Hinnant, C. W., and Zucker, K. W. (2020). A clinical perspective of the U.S. anti-vaccination epidemic: considering marginal costs and benefits, CDC best practices guidelines, free riders, and herd immunity. Vaccine 38, 7877–7879. doi: 10.1016/j.vaccine.2020.10.068

PubMed Abstract | CrossRef Full Text | Google Scholar

Asturias, E. J., Wharton, M., Pless, R., MacDonald, N. E., Chen, R. T., Andrews, N., et al. (2016). Contributions and challenges for worldwide vaccine safety: The global advisory committee on vaccine safety at 15 years. Vaccine 34, 3342–3349. doi: 10.1016/j.vaccine.2016.05.018

PubMed Abstract | CrossRef Full Text | Google Scholar

Berezin, M., and Eads, A. (2016). Risk is for the rich? Childhood vaccination resistance and a culture of health. Soc. Sci. Med. 165, 233–245. doi: 10.1016/j.socscimed.2016.07.009

PubMed Abstract | CrossRef Full Text | Google Scholar

Bianco, A., Mascaro, V., Zucco, R., and Pavia, M. (2019). Parent perspectives on childhood vaccination: how to deal with vaccine hesitancy and refusal? Vaccine 37, 984–990. doi: 10.1016/j.vaccine.2018.12.062

PubMed Abstract | CrossRef Full Text | Google Scholar

Bocquier, A., Fressard, L., Cortaredona, S., Zaytseva, A., Ward, J., Gautier, A., et al. (2018). Social differentiation of vaccine hesitancy among French parents and the mediating role of trust and commitment to health: a nationwide cross-sectional study. Vaccine 36, 7666–7673. doi: 10.1016/j.vaccine.2018.10.085

PubMed Abstract | CrossRef Full Text | Google Scholar

Boston University School of Public Health (2022). The Health Belief Model. Boston University School of Public Health. Available online at: https://sphweb.bumc.bu.edu/otlt/mph-modules/sb/behavioralchangetheories/behavioralchangetheories2.html (accessed November 5, 2022).

Google Scholar

Bryden, G., Browne, M., Rockloff, M., and Unsworth, C. (2018). Anti-vaccination and pro CAM attitudes both reflect magical beliefs about health. Vaccine 36, 1227–1234. doi: 10.1016/j.vaccine.2017.12.068

PubMed Abstract | CrossRef Full Text | Google Scholar

Buchanan, R., and Beckett, R. D. (2014). Assessment of vaccination- related information for consumers available on facebook. Health Info. Libr. J. 31, 227–234. doi: 10.1111/hir.12073

PubMed Abstract | CrossRef Full Text | Google Scholar

Cadeddu, C., Daugbjerg, S., Ricciardi, W., and Rosano, A. (2020). Beliefs towards vaccination and trust in the scientific community in Italy. Vaccine 38, 6609–6617. doi: 10.1016/j.vaccine.2020.07.076

PubMed Abstract | CrossRef Full Text | Google Scholar

Carpiano, R., Polonijo, A. N., Gilbert, N., Cantin, L., and Dub,é, E. (2019). Socioeconomic status differences in parental immunization attitudes and child immunization in Canada: findings from the 2013 childhood national immunization coverage survey (CNICS). Prev. Med. 123, 278–287. doi: 10.1016/j.ypmed.2019.03.033

PubMed Abstract | CrossRef Full Text | Google Scholar

Carrion, M. (2018). An ounce of prevention: identifying cues to (in)action for maternal vaccine refusal. Qual. Health Res. 28, 2183–2194. doi: 10.1177/1049732318792505

PubMed Abstract | CrossRef Full Text | Google Scholar

Chung, Y., Schamel, J., Fisher, A., and Frew, P. M. (2017). Influences on immunization decision-making among US parents of young children. Matern. Child Health J. 21, 2178–2187. doi: 10.1007/s10995-017-2336-6

PubMed Abstract | CrossRef Full Text | Google Scholar

Dempsey, A., Maertens, J., Beaty, B., and O'Leary, S. T. (2015). Characteristics of users of a tailored, interactive website for parents and its impact on adolescent vaccination attitudes and uptake. BMC Res. Notes 8, 739–739. doi: 10.1186/s13104-015-1721-8

PubMed Abstract | CrossRef Full Text | Google Scholar

Dhaliwal, D., and Mannion, C. (2020). Antivaccine messages on facebook: preliminary audit. JMIR Public Health Surveill. 6, 131–138. doi: 10.2196/18878

PubMed Abstract | CrossRef Full Text | Google Scholar

Dzieciolowska, S., Hamel, D., Gadio, S., Dionne, M., Gagnon, D., Robitaille, L., et al. (2021). Covid-19 vaccine acceptance, hesitancy, and refusal among Canadian healthcare workers: a multicenter survey. Am. J. Infect. Control 49, 1152–1157. doi: 10.1016/j.ajic.2021.04.079

PubMed Abstract | CrossRef Full Text | Google Scholar

Elkalmi, R., Jamshed, S. Q., and Suhaimi, A. M. (2021). Discrepancies and similarities in attitudes, beliefs, and familiarity with vaccination between religious studies and science students in Malaysia: a comparison study. J. Relig. Health 60, 2411–2427. doi: 10.1007/s10943-021-01212-x

PubMed Abstract | CrossRef Full Text | Google Scholar

Faasse, K., Chatman, C. J., and Martin, L. R. (2016). A comparison of language use in pro- and anti-vaccination comments in response to a high profile facebook post. Vaccine 34, 5808–5814. doi: 10.1016/j.vaccine.2016.09.029

PubMed Abstract | CrossRef Full Text | Google Scholar

Fall, E., Izaute, M., and Chakron-Baggioni, N. (2018). How can the health belief model and self determination theory predict both influenza vaccination and vaccination intention? A longitudinal study among university students. Psychol. Health 33, 746–764. doi: 10.1080/08870446.2017.1401623

PubMed Abstract | CrossRef Full Text | Google Scholar

Fine, P. E. (1993). Herd immunity: history, theory, practice. Epidemiol. Rev. 15, 265–302. doi: 10.1093/oxfordjournals.epirev.a036121

PubMed Abstract | CrossRef Full Text | Google Scholar

Fowler, G., Baggs, J. M., Weintraub, E. S., Martin, S. W., McNeil, M. M., and Gust, D. A. (2006). Factors influencing laboratory workers' decisions to accept or decline anthrax vaccine adsorbed (AVA): results of a decision-making study in CDC's anthrax vaccination program. Pharmacoepidemiol. Drug Saf. 15, 880–888. doi: 10.1002/pds.1302

PubMed Abstract | CrossRef Full Text | Google Scholar

Freeman, G., Lambe, S., Yu, L.-M., Freeman, J., Chadwick, A., Vaccari, C., et al. (2021). Injection fears and COVID-19 vaccine hesitancy. Psychol. Med. 1–11. doi: 10.1017/S0033291721002609

PubMed Abstract | CrossRef Full Text | Google Scholar

Gagneur, A., Lemaître, T., Gosselin, V., Farrands, A., Carrier, N., Petit, G., et al. (2018). A postpartum vaccination promotion intervention using motivational interviewing techniques improves short-term vaccine coverage: PromoVac study. BMC Public Health 18, 811. doi: 10.1186/s12889-018-5724-y

PubMed Abstract | CrossRef Full Text | Google Scholar

Goldberg, Z., and Richey, S. (2020). Anti-vaccination beliefs and unrelated conspiracy theories. World Affairs 183, 105–124. doi: 10.1177/0043820020920554

CrossRef Full Text | Google Scholar

Health Human Services. (2021). Vaccine Side Effects. Office of Infectious Diseases and HIV/AIDS Policy; U.S. Department of Health and Human Services (HHS); Vaccine Side Effects. Available online at: https://www.hhs.gov/immunization/basics/safety/side-effects/

Google Scholar

Helps, C., Leask, J., Barclay, L., and Carter, S. (2019). Understanding non-vaccinating parents' views to inform and improve clinical encounters: a qualitative study in an Australian community. BMJ Open 9, e026299. doi: 10.1136/bmjopen-2018-026299

PubMed Abstract | CrossRef Full Text | Google Scholar

Hodson, R. (2019). Vaccines. Nature 575, S43. doi: 10.1038/d41586-019-03635-9

PubMed Abstract | CrossRef Full Text | Google Scholar

Hong, Q. N., Pluye, P., Fàbregues, S., Bartlett, G., Boardman, F., Cargo, M., et al (2018). Mixed Methods Appraisal Tool (MMAT), Version 2018. Canadian Intellectual Property Office. Available online at: http://mixedmethodsappraisaltoolpublic.pbworks.com/w/page/127425302/About%20the%20MMAT (accessed September 1, 2021).

Google Scholar

Hornsey, M., Harris, E. A., and Fielding, K. S. (2018). The psychological roots of anti vaccination attitudes: a 24-nation investigation. Health Psychol. 37, 307–315. doi: 10.1037/hea0000586

PubMed Abstract | CrossRef Full Text | Google Scholar

Huynh, H., and Senger, A. R. (2021). A little shot of humility: Intellectual humility predicts vaccination attitudes and intention to vaccinate against COVID-19. J. Appl. Soc. Psychol. 51, 449–460. doi: 10.1111/jasp.12747

PubMed Abstract | CrossRef Full Text | Google Scholar

Kriss, L. A., Quick, B. L., Rains, S. A., and Barbati, J. L. (2022). Psychological reactance theory and COVID-19 vaccine mandates: the roles of threat magnitude and direction of threat. J. Health Commun. 27, 654–663. doi: 10.1080/10810730.2022.2148023

PubMed Abstract | CrossRef Full Text | Google Scholar

Lemaitre, T., Carrier, N., Farrands, A., Gosselin, V., Petit, G., and Gagneur, A. (2019). Impact of a vaccination promotion intervention using motivational interview techniques on long-term vaccine coverage: the PromoVac strategy. Hum. Vaccin. Immunother. 15, 732–739. doi: 10.1080/21645515.2018.1549451

PubMed Abstract | CrossRef Full Text | Google Scholar

Luyten, J., Desmet, P., Dorgali, V., Hens, N., and Beutels, P. (2014). Kicking against the pricks: vaccine sceptics have a different social orientation. Eur. J. Public Health 24, 310–314. doi: 10.1093/eurpub/ckt080

PubMed Abstract | CrossRef Full Text | Google Scholar

Martinez-Berman, L., McCutcheon, L., and Huynh, H. P. (2021). Is the worship of celebrities associated with resistance to vaccinations? Relationships between celebrity admiration, anti-vaccination attitudes, and beliefs in conspiracy. Psychol. Health Med. 26, 1063–1072. doi: 10.1080/13548506.2020.1778754

PubMed Abstract | CrossRef Full Text | Google Scholar

McKenzie, J. E., Brennan, S. E., Ryan, R. E., Thomson, H. J., Johnston, R. V., and Thomas, J. (Ed.) (2022). “Defining the criteria for including studies and how they will be grouped for the synthesis,” in Cochrane Handbook for Systematic Reviews of Interventions, 6th Edn, eds J. P. T. Higgins, J. Thomas, J. Chandler, M. Cumpston, T. Li, M. J. Page, and V. A. Welch (Cochrane). Available online at: www.training.cochrane.org/handbook (accessed September 1, 2021).

Google Scholar

Michael, C., Ogbuanu, I. U., Storms, A. D., Ohuabunwo, C. J., Corkum, M., Ashenafi, S., et al. (2014). An assessment of the reasons for oral poliovirus vaccine refusals in northern Nigeria. J. Infect. Dis. 210, S125–S130. doi: 10.1093/infdis/jiu436

PubMed Abstract | CrossRef Full Text | Google Scholar

Motta, M., Callaghan, T., and Sylvester, S. (2018). Knowing less but presuming more: dunning kruger effects and the endorsement of anti-vaccine policy attitudes. Soc. Sci. Med. 211, 274–281. doi: 10.1016/j.socscimed.2018.06.032

PubMed Abstract | CrossRef Full Text | Google Scholar

Motta, M., Callaghan, T., Sylvester, S., and Lunz-Trujillo, K. (2021). Identifying the prevalence, correlates, and policy consequences of anti-vaccine social identity. Polit. Groups Ident. 1–15. doi: 10.1080/21565503.2021.1932528

CrossRef Full Text | Google Scholar

Murphy, J., Vallières, F., Bentall, R. P., Shevlin, M., McBride, O., Hartman, T. K., et al. (2021). Psychological characteristics associated with COVID-19 vaccine hesitancy and resistance in Ireland and the United Kingdom. Nat. Commun. 12, 29–29. doi: 10.1038/s41467-020-20226-9

PubMed Abstract | CrossRef Full Text | Google Scholar

National Center for Immunization and Respiratory Diseases (2020). 14 Diseases you Almost Forgot About (Thanks to Vaccines). Center for Disease Control and Prevention.

Google Scholar

National Centre for Immunisation Research Surveillance (2021). History of Immunisation in Australia. NCIRS. Available online at: https://www.ncirs.org.au/health-professionals/history-immunisation-australia (accessed November 5, 2022).

Google Scholar

Nour, R. (2019). A systematic review of methods to improve attitudes towards childhood vaccinations. Cureus 11, e5067. doi: 10.7759/cureus.5067

PubMed Abstract | CrossRef Full Text | Google Scholar

Nowak, G., Evans, N. J., Wojdynski, B. W., Ahn, S. J., Len-Rios, M. E., Carera, K., et al. (2020). Using immersive virtual reality to improve the beliefs and intentions of influenza vaccine avoidant 18-to-49-year-olds: considerations, effects, and lessons learned. Vaccine 38, 1225–1233. doi: 10.1016/j.vaccine.2019.11.009

PubMed Abstract | CrossRef Full Text | Google Scholar

Okuhara, T., Ishikawa, H., Kato, M., Okada, M., and Kiuchi, T. (2018). A qualitative analysis of the beliefs of Japanese anti-influenza vaccination website authors. Heliyon 4, e00609. doi: 10.1016/j.heliyon.2018.e00609

PubMed Abstract | CrossRef Full Text | Google Scholar

Okuhara, T., Ishikawa, H., Okada, H., Ueno, H., and Kiuchi, T. (2020). Dual-process theories to counter the anti-vaccination movement. Prev. Med. Rep. 20, 101205. doi: 10.1016/j.pmedr.2020.101205

PubMed Abstract | CrossRef Full Text | Google Scholar

Okuhara, T., Ishikawa, H., Okada, M., Kato, M., and Kiuchi, T. (2017). A readability comparison of anti-versus pro-influenza vaccination online messages in Japan. Prev. Med. Rep. 6, 47–52. doi: 10.1016/j.pmedr.2017.02.013

PubMed Abstract | CrossRef Full Text | Google Scholar

Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., et al. (2021). The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 372, n71. doi: 10.1136/bmj.n71

PubMed Abstract | CrossRef Full Text | Google Scholar

Peretti-Watel, P., Larson, H. J., Ward, J. K., Schulz, W. S., and Verger, P. (2015). Vaccine hesitancy: clarifying a theoretical framework for an ambiguous notion. PLoS Curr. 7. doi: 10.1371/currents.outbreaks.6844c80ff9f5b273f34c91f71b7fc289

PubMed Abstract | CrossRef Full Text | Google Scholar

Pluviano, S., Watt, C., Ragazzini, G., and Della Sala, S. (2019). Parents' beliefs in misinformation about vaccines are strengthened by pro-vaccine campaigns. Cogn. Process. 20, 325–331. doi: 10.1007/s10339-019-00919-w

PubMed Abstract | CrossRef Full Text | Google Scholar

Pot, M., Paulussen, T. W. G. M., Ruiter, R. A. C., Eekhout, I., de Melker, H. E., Spoelstra, M. E. A., et al. (2017). Effectiveness of a web-based tailored intervention with virtual assistants promoting the acceptability of HPV vaccination among mothers of invited girls: randomized controlled trial. J. Med. Internet Res. 19, e312–e312. doi: 10.2196/jmir.7449

PubMed Abstract | CrossRef Full Text | Google Scholar

Reich, J. (2016). Of natural bodies and antibodies: parents' vaccine refusal and the Dichotomies of natural and artificial. Soc. Sci. Med. 157, 103–110. doi: 10.1016/j.socscimed.2016.04.001

PubMed Abstract | CrossRef Full Text | Google Scholar

Restivo, V., Costantino, C., Fazio, T. F., Casuccio, N., D'Angelo, C., Vitale, F., et al. (2018). Factors associated with HPV vaccine refusal among young adult women after ten years of vaccine implementation. Int. J. Environ. Res. Public Health 15, 770. doi: 10.3390/ijerph15040770

PubMed Abstract | CrossRef Full Text | Google Scholar

Riedel, S. (2005). Edward Jenner and the history of smallpox and vaccination. Proceedings 18, 21–25. doi: 10.1080/08998280.2005.11928028

PubMed Abstract | CrossRef Full Text | Google Scholar

Romijnders, J., van Seventer, S. L., Scheltema, M., van Osch, L., de Vries, H., and Mollema, L. (2019). A deliberate choice? Exploring factors related to informed decision-making about childhood vaccination among acceptors, refusers, and partial acceptors. Vaccine 37, 5637–5644. doi: 10.1016/j.vaccine.2019.07.060

PubMed Abstract | CrossRef Full Text | Google Scholar

Rossen, I., Hurlstone, M. J., Dunlop, P. D., and Lawrence, C. (2019). Accepters, fence sitters, or rejecters: moral profiles of vaccination attitudes. Soc. Sci. Med. 224, 23–27. doi: 10.1016/j.socscimed.2019.01.038

PubMed Abstract | CrossRef Full Text | Google Scholar

Rozbroj, J., Lyons, A., and Lucke, J. (2020). Vaccine-Hesitant and vaccine-refusing parents' reflections on the way parenthood changed their attitudes to vaccination. J. Community Health 45, 63–72. doi: 10.1007/s10900-019-00723-9

PubMed Abstract | CrossRef Full Text | Google Scholar

Rozbroj, T., Lyons, A., and Lucke, J. (2019a). Psychosocial and demographic characteristics relating to vaccine attitudes in Australia. Patient Educ. Couns. 102, 172–179. doi: 10.1016/j.pec.2018.08.027

PubMed Abstract | CrossRef Full Text | Google Scholar

Rozbroj, T., Lyons, A., and Lucke, J. (2019b). The mad leading the blind: perceptions of the vaccine-refusal movement among Australians who support vaccination. Vaccine 37, 5986–5993. doi: 10.1016/j.vaccine.2019.08.023

PubMed Abstract | CrossRef Full Text | Google Scholar

Rozbroj, T., Lyons, A., and Lucke, J. (2022). Understanding how the Australian vaccine refusal movement perceives itself. Health Soc. Care Community 30, 695–705. doi: 10.1111/hsc.13182

PubMed Abstract | CrossRef Full Text | Google Scholar

Salmon, D., Dudley, M., Glanz, J., and Omer, S. (2015). Vaccine hesitancy: causes, consequences, and a call to action. Am. J. Prev. Med. 49, 391–398. doi: 10.1016/j.amepre.2015.06.009

PubMed Abstract | CrossRef Full Text | Google Scholar

Shapiro, G. K., Tatar, O., Dube, E., Amsel, R., Knauper, B., Naz, A., et al. (2018). The vaccine hesitancy scale: psychometric properties and validation. Vaccine 36, 660–667. doi: 10.1016/j.vaccine.2017.12.043

PubMed Abstract | CrossRef Full Text | Google Scholar

Smith, M., and Graham, T. (2019). Mapping the anti-vaccination movement on facebook. Inform. Commun. Soc. 22, 1310–1327. doi: 10.1080/1369118X.2017.1418406

CrossRef Full Text | Google Scholar

Smith, P. J., Chu, S. Y., and Barker, L. E. (2004). Children who have received no vaccines: who are they and where do they live? Pediatrics 114, 187–195. doi: 10.1542/peds.114.1.187

PubMed Abstract | CrossRef Full Text | Google Scholar

Tomljenovic, J., Bubic, A., and Erceg, N. (2020). It just doesn't feel right—the relevance of emotions and intuition for parental vaccine conspiracy beliefs and vaccination uptake. Psychol. Health 35, 538–554. doi: 10.1080/08870446.2019.1673894

PubMed Abstract | CrossRef Full Text | Google Scholar

Tustin, J., Crowcroft, N. S., Gesink, D., Johnson, I., and Keelan, J. (2018). Internet exposure associated with Canadian parents' perception of risk on childhood immunization: cross sectional study. JMIR Public Health Surveill. 4, 238–249. doi: 10.2196/publichealth.8921

PubMed Abstract | CrossRef Full Text | Google Scholar

Wada, K., and Smith, D. R. (2015). Mistrust surrounding vaccination recommendations by the Japanese government: results from a national survey of working-age individuals health behavior, health promotion and society. BMC Public Health 15, 426. doi: 10.1186/s12889-015-1772-8

PubMed Abstract | CrossRef Full Text | Google Scholar

Widder, R. (2017). Learning to use motivational interviewing effectively: modules. J. Contin. Educ. Nurs. 48, 312–319. doi: 10.3928/00220124-20170616-08

PubMed Abstract | CrossRef Full Text | Google Scholar

Wiley, K. E., Leask, J., Attwell, K., Helps, C., Degeling, C., Ward, P., et al. (2020). Parenting and the vaccine refusal process: a new explanation of the relationship between lifestyle and vaccination trajectories. Soc. Sci. Med. 263, 113259. doi: 10.1016/j.socscimed.2020.113259

PubMed Abstract | CrossRef Full Text | Google Scholar

Wolfe, R. M., and Sharp, L. K. (2002). Anti-vaccinationists past and present. BMJ 325, 430–432. doi: 10.1136/bmj.325.7361.430

PubMed Abstract | CrossRef Full Text | Google Scholar