by Ben Ferguson, BMus Jazz Studies, BSN

Justin Gillespie, BSc Life Sc., BSN

Raman Kular, BSc Bio

Kolten Muirhead, BSc Bio.

Lauren Van Rassel, BSc Health Sc., BSN

Citation: Ferguson, B., Gillespie, J., Kular, R., Muirhead, K., & Van Rassel, L. (2024). Evaluating Sources Influencing Vaccine Hesitancy: A Systematic Review. Canadian Journal of Nursing Informatics, 19(2).  https://cjni.net/journal/?p=13118

Background

According to the World Health Organization (2019), vaccines are a crucial part of primary health care and they are the key to saving millions of lives, globally, each year. Vaccines are the key to controlling infectious disease and stopping infectious disease outbreaks (World Health Organization, 2019). The WHO has gone so far as to say that vaccines play a role in underpinning global security. Despite the importance of vaccines, there is a concerning trend of countries going backwards in terms of vaccine progress (World Health Organization, 2019). An example of this shift would be in the progress that has been made and lost in the eradication of measles. The WHO estimates that 30 million deaths have been prevented globally due to measles because of the vaccine (World Health Organization, 2021). Despite this, progress with measles eradication has been stalling, if not reversing. Measles outbreaks are now happening in countries who had at one point in time eradicated measles (World Health Organization, 2021). It is theorized that the ongoing COVID-19 pandemic has influenced health-seeking behaviours, as well as access to immunization services.

Vaccine hesitancy is not something new, though it does appear to be having a resurgence. There has been a long-standing belief that vaccines can cause more harm than the diseases they are protecting against. Schwartz (2012) states that through the nineteenth century, there were anti-vaccination groups in the United States. These groups typically consisted of people with similar worldviews, socioeconomic status, and ethnicities (Schwartz, 2012). They have also historically included health care practitioners who were perceived as going against the values and views of their own professions (Schwartz, 2012). Before the COVID-19 pandemic, one of the more prominent examples of vaccine hesitancy was started by Wakefield and his 1998 study on the MMR vaccine and a link with autism spectrum disorder (ASD) published in The Lancet (Pivetti et al., 2020). Though this study was disproven, and there have been plenty of studies proving that there is no link between the MMR vaccine and ACD (Pivetti et al., 2020), the beliefs that fuel vaccine hesitancy are still very much prevalent, and appear to have escalated during the COVID-19 pandemic.

Emerging information during the COVID-19 pandemic has indicated that health-seeking behaviours are constantly shifting and being influenced at a rapid pace. Part of this is theorized to be due to the reach of social media and social networks. Further, with this shift to information being readily accessible using technology it is difficult to determine where information is coming from that can influence health-seeking behaviours. This study will focus on individuals who are already vaccine hesitant and address how they evaluate their sources of vaccine information and education. The working definition we are using for vaccine hesitancy was developed by the WHO as “a delay in the acceptance or refusal of vaccines despite the availability of vaccination services” (MacDonald, 2015, p. 4163).

Methods

Search Strategy

A search of the literature was performed using the CINAHL database. This database is focused specifically on nursing research and research applicable to nursing and health practice. All papers were exported manually, and the literature search occurred between October and November 2021. The search was focused on the themes of vaccine hesitancy and evaluation of vaccine-related information. Keywords that were used included vaccine, hesitancy, social media, vaccine hesitancy, qualitative, peer-reviewed.

Selection of Studies

This systematic review only included the use of qualitative studies. Qualitative studies have been deemed as rich sources of data for nursing practice, and one of the aims for this study is to do a review of the qualitative literature. This excludes any form of quantitative study, including but not limited to observation, correlation, experimental, and descriptive quantitative studies. Studies that were included only had populations that identified as either vaccine hesitant or vaccine resistant. The papers had to identify sources of information that led these populations to vaccine hesitancy or vaccine resistance. The literature search and review consisted of papers published between the years of 2016 and 2021. Studies published within the most recent five years were chosen as (LoBiondo-Wood et al., 2017) stated that it is best practice to reference research that is the most recent, and therefore most relevant. All papers included in this systematic review were published in English and were peer-reviewed. All studies included were required to have full-text available and were primary research articles. In the CINAHL search that included the keywords and study requirements, there were 25 study articles that might be suitable. Of the 25 initial studies, 14 fit the criteria and were applicable for use in this systematic review.

The process of screening was done by five authors in tandem. After addressing the aim of the study, we collaborated to come up with our agreed upon inclusion and exclusion criteria. Then we applied our inclusion and exclusion criteria to identical searches and all five authors reviewed the studies that would be included in the review. The inclusion and criteria were specified and agreed upon between authors before the literature search started. The inclusion and exclusion criteria are described below.

Inclusion criteria

• Must be a qualitative study
• Must be published in the CINAHL database
• Must focus on vaccine hesitant or vaccine resistant populations
• Must have a focus on information influencing vaccine hesitancy or resistance
• Must be published between 2016 and 2021
• Must be published in English
• Must be peer-reviewed, have full-text and pdf available

Exclusion criteria

• Not qualitative (Quantitative)
• Population does not focus on vaccine hesitant or vaccine resistant populations
• Does not focus on information influencing vaccine hesitancy or resistance
• Was published outside the years of 2016 to 2021
• Was not published in English
• Was not peer-reviewed, did not have full-text available, and did not have pdf available
• Was not available in the CINAHL database

Data Extraction

To extract the data, we created our own matrix to include information that the authors deemed most appropriate to include in this systematic review (Table 1). This information was also used for the quality assessment. We included the author, date of publishing, the theoretical and/or conceptual framework, the research question, methodology, analysis and results, conclusions, implications for future research, implications for practice, and a CASP score. The data was extracted by two authors and was verified by three additional authors. Any discrepancies in data extraction were discussed and resolved in a group setting among the five authors. Ideally, having two authors extract the data would help maintain validity in the findings. 

Table 1

Data Extraction Tool Matrix

Quality Assessment

To assess the quality of the studies, we used the Critical Appraisal Skills Programme, or CASP (2019) appraisal tool. This tool is broken down into three sections. The sections include determining the validity of the results of the study, the results, and whether the results help locally (Critical Appraisal Skills Programme, 2019). There were 10 questions on the CASP forms that summarized these sections. We were able to develop a CASP score by answering the questions with a binary yes (1) or no (0). We did not include the answer of maybe, as if there were doubts about whether a piece of criterion was met, we assumed that the criterion was unmet. The score comes from the addition of the results of the binary yes (1) and no (0) results.

Results

         In this systematic review we explored articles that focussed on vaccine hesitancy and how people evaluate their vaccine-related resources (e.g. education, health care services, social media). Through our analysis we found that four main themes emerged: distrust in the medical system and/or government, information dissemination, education, and personal or cultural beliefs. Our systematic review findings can be viewed in Table 1. Articles originated from countries around the world including: Austria, India (3), Italy(2), Philippines, UK(3), USA(2), Romania, and Turkey. From our analysis we found that vaccine hesitancy is a worldwide concern that needs to be better understood in order to formulate strategies to address it.

Distrust in medicine/government

Distrust in the medical system and government plays a large role in vaccine hesitancy in the public. The articles we looked at outlined distrust stemming from the medical community regarding the efficacy and safety of vaccines to be a contributing factor for vaccine hesitancy. Many participants felt not enough research had been conducted regarding the long term and adverse effects of vaccines, specifically the COVID-19 vaccine. Along with distrust in the scientific aspect of vaccines some articles stated that participants did not feel comfortable in approaching medical professionals. The discomfort and inability to confer with a medical professional regarding concerns about vaccines led many parents to avoid getting their children immunized. In one specific article, past vaccination programs were discontinued due to safety concerns around the vaccine and members of the communities were left with unanswered questions (Landicho-Guevarra et al., 2021). This type of ineffective communication has been seen to increase rates of vaccine hesitancy and decrease immunization rates in communities. The distrust in the government came from lack of confidence in political parties in power. Some participants voiced reasoning for vaccine hesitancy to be linked to their personal political views and how they differ from the current party in power; since these participants lacked trust and confidence in their current government, they also lacked confidence in that government’s ability to develop a safe vaccine and/or disseminate correct information about available vaccines.

Information dissemination

Information dissemination was characterized by the way that the general public received their information regarding vaccinations. One major recurrence in the studies analysed was the use of media, the internet, and social media as a way to spread misinformation regarding vaccines. A large portion of people who are vaccine hesitant cite information from non peer-reviewed or credible sources as the basis of their arguments. Facebook and other similar social media sites have given members of the public (who are not researchers or medical professionals) a large platform to spread their biased or incorrect opinions on vaccines. Healthcare professionals did not appear immune to this spread of false information either as there are multiple sources stating a not insignificant percentage of healthcare providers used social media as their primary source of information regarding vaccines. This ultimately leads to healthcare professionals themselves being a source of misinformation dissemination instead of providing evidence-based, medically sound advice. This creates a positive feedback loop where now the people receiving this false medical advice may go back onto social media to claim that “their doctor” or “a nurse” told them something so it must be true. Finally, another recurring motif within this theme of information dissemination was the use of anecdotes and beliefs from friends and family as a primary source of information. Participants, particularly those identified in the theme above about government or medical distrust, were much more inclined to believe the people closest to them.

Education

Another common theme found from the reviewed articles was a lack of education. Education is not limited to just the public but includes health care workers as well. Participants in the articles stated that a lack of education about the vaccine including the possible benefits and long term effects was not clearly communicated. This also ties into the misinformation spread about vaccinations. The public is not educated or cannot access the proper channels to find accurate information about vaccines leading them to trust non credible sources. The participants in the Lehner et al. (2021) article stated that education about vaccines was not included in their curriculum and that midwives had to dig up information themselves.  This was also mentioned in some of the other articles that focused on health care professionals as participants. Health care professionals not being able to adequately answer the questions about vaccines from the public, specifically parents, has led to vaccine hesitancy. Proper education of both the public and health care professionals about vaccines was a common intervention stated in many of the articles. The articles that focused on parents and low childhood immunization rates due to vaccine hesitancy in parents outlined the importance of educating pregnant women and soon to be parents about the benefits of vaccinations as well as, addressing their concerns to decrease vaccine hesitancy.

Beliefs

Personal and cultural beliefs play a large role in peoples’ decision to get themselves, or their family, vaccinated. Participants in multiple articles felt that their age or level of perceived health was sufficient to fight off any diseases they may contract. In another article, vaccine hesitancy stemmed from vaccines being viewed as non-essential for children as their parents were able to reach adulthood without the need for them; the lack of wide-spread disease or pandemic until recent years has been cited as evidence for these vaccine-hesitant attitudes (Landicho-Guevarra, et al. 2021). Beliefs about vaccines and their safety were also explored in an article that focused on mothers who had children with autism spectrum disorder (ASD) (Pivetti et al., 2020). Though there is a substantial body of evidence that refutes a relationship between vaccines and ASD, there are still minority groups that strongly believe this causal relationship exists (Pivetti et al., 2020). Furthermore, in their USA-based article, Geana et al. (2021) found that religious beliefs and conspiracy theories were prevalent reasons for the inmates’ vaccine hesitancy or refusal.

Discussion

This systematic review focused on 14 articles that detailed vaccine knowledge, hesitancy, and sources of information. Of those 14 articles examined, only five actually stated their operational definition of what vaccine hesitancy is. Four of these articles used the WHO working definition that vaccine hesitancy is “a delay in the acceptance or refusal of vaccines despite the availability of vaccination services” (MacDonald, 2015, p. 4163), though one article did not cite the WHO, but used the same wording for the definition. The fifth article created their own operational definition which, although similar to the WHO definition, had its own unique wording. Of the remaining nine articles, a few did not use the term vaccine hesitancy at all while most used the term without referencing or creating a definition. This creates a bit of an issue when attempting to compare the research between articles as for the ones who have chosen not to define what vaccine hesitancy is, we have no way of knowing exactly how their definition relates to those of other studies. What is considered vaccine hesitancy in one study may very well not be in another which makes direct comparisons tricky. What makes this even more strange is that this published definition by the WHO was released before any of these studies were published. Moving forwards there is a need for more studies to adopt the WHO definition to create unity in findings about vaccine hesitancy.

Overall, the methodological quality of the papers reviewed was high with an average CASP score of 8.4 and a lowest score of 7. However, only one paper examined scored a perfect 10 and most papers lost points specifically for the researchers not examining their relationship to the participants. This is significant in that this represents a possible source of internal bias for the researchers when not addressed as these relationships may have affected some of their data collection and overall research methods. Aside from the lack of examination of relationships, most of the other points lost when examining the CASP of each article were mixed with no real pattern emerging.

The common interventions to target vaccine hesitancy discussed in the articles were focused on education for both the public and health care professionals, broadcasting of accurate information through media outlets and improving vaccination programs. Education and addressing the underlying factors for vaccine hesitancy in vulnerable populations is key to decreasing vaccine hesitancy and increasing vaccination rates in these populations. A potential implication for future vaccination programs will be to address these shortcomings when developing the programs.

Conclusion

Vaccine hesitancy is a major concern in the realm of public health, with recent trends showing more and more people becoming vaccine hesitant in the era of COVID-19. With the rise of the anti-vaccination movement and outbreaks of preventable diseases with available vaccines, now more than ever there is a need to better understand vaccine hesitancy both globally and specifically to different countries or cultural groups. A review of the concept of vaccine hesitancy showed about a third of the studies reviewed used the WHO definition of vaccine hesitancy being a delay in the acceptance or refusal of vaccines despite the availability of vaccination services, with one paper creating their own definition and the remaining papers just used the term without any sort of definition. The quality of the papers was generally high, though we noted that most of the papers were at risk of bias due to the researchers not considering how their relationship with the participants may have influenced the methodology and data of the study. Ultimately this review highlights a need for future research to consolidate a singular definition of vaccine hesitancy and to make sure they are defining the term when using it. This will allow for easier comparison studies to be conducted when seeing if vaccine hesitancy stems from the same sources or is endemic to similar populations.

References

Critical Appraisal Skills Programme (2019). CASP: Systematic Review Checklist. [online] https://casp-uk.b-cdn.net/wp-content/uploads/2018/03/CASP-Systematic-Review-Checklist-2018_fillable-form.pdf

Danabal, K. G. M., Magesh, S. S., Saravanan, S., & Gopichandran, V. (2021). Attitude towards COVID 19 vaccines and vaccine hesitancy in urban and rural communities in Tamil Nadu, india – a community-based survey. BMC Health Services Research, 21(1), 1-994. https://doi.org/10.1186/s12913-021-07037-4

Del Duca, E., Chini, L., Graziani, S., Sgrulletti, M., Moschese, V., Moschese, V., Chini, L., Sgrulletti, M., Dellepiane, R. M., Martire, B., Sangerardi, M., Montin, D., Ottaviano, G., Rizzo, C., Duse, M., Marseglia, G., & with the Italian Pediatric Immunology and Allergology Society (SIAIP) Vaccine Committee. (2021). Pediatric health care professionals’ vaccine knowledge, awareness and attitude: A survey within the Italian society of pediatric allergy and immunology. Italian Journal of Pediatrics, 47(1), 1-183. https://doi.org/10.1186/s13052-021-01090-9

Elwy, A. R., Clayman, M. L., LoBrutto, L., Miano, D., Ann Petrakis, B., Javier, S., Erhardt, T., Midboe, A. M., Carbonaro, R., Jasuja, G. K., Maguire, E. M., Kyrish, A., Asch, S. M., Gifford, A. L., & McInnes, D. K. (2021). Vaccine hesitancy as an opportunity for engagement: A rapid qualitative study of patients and employees in the U.S. veteran’s affairs healthcare system. Vaccine: X, 9, 100116. https://doi.org/10.1016/j.jvacx.2021.100116

Geana, M. V., Anderson, S., & Ramaswamy, M. (2021). COVID-19 vaccine hesitancy among women leaving jails: A qualitative study. Public Health Nursing (Boston, Mass.), 38(5), 892-896. https://doi.org/10.1111/phn.12922

Jain, J., Saurabh, S., Kumar, P., Verma, M. K., Goel, A. D., Gupta, M. K., Bhardwaj, P., & Raghav, P. R. (2021). COVID-19 vaccine hesitancy among medical students in India. Epidemiology and Infection, 149. https://doi.org/10.1017/S0950268821001205

Landicho-Guevarra, J., Reñosa, M. D. C., Wachinger, J., Endoma, V., Aligato, M. F., Bravo, T. A., Landicho, J., Bärnighausen, K., & McMahon, S. A. (2021). Scared, powerless, insulted and embarrassed: Hesitancy towards vaccines among caregivers in Cavite province, the Philippines. BMJ Global Health, 6(9), e006529. https://doi.org/10.1136/bmjgh-2021-006529

Lehner, L., Gribi, J., Hoffmann, K., Paul, K. T., & Kutalek, R. (2021). Beyond the “information deficit model” – understanding vaccine-hesitant attitudes of midwives in Austria: A qualitative study. BMC Public Health, 21(1), 1-1671. https://doi.org/10.1186/s12889-021-11710-y

LoBiondo-Wood, G., Haber, J. & Singh, M. (2017). Nursing Research in Canada: Methods, Critical Appraisal, and Utilization. (4^th ed.). Elsevier.

Lockyer, B., Islam, S., Rahman, A., Dickerson, J., Pickett, K., Sheldon, T., Wright, J., McEachan, R., Sheard, L., Bradford Institute for Health Research Covid-19 Scientific Advisory Group, & the Bradford Institute for Health Research Covid?19 Scientific Advisory Group. (2021). Understanding COVID?19 misinformation and vaccine hesitancy in context: Findings from a qualitative study involving citizens in Bradford, UK. Health Expectations: An International Journal of Public Participation in Health Care and Health Policy, 24(4), 1158-1167. https://doi.org/10.1111/hex.13240

Luo, S., Xin, M., Wang, S., Zhao, J., Zhang, G., Li, L., Li, L., & Tak-fai Lau, J. (2021). Behavioural intention of receiving COVID-19 vaccination, social media exposures and peer discussions in China. Epidemiology and Infection, 149, e158-e158. https://doi.org/10.1017/S0950268821000947

MacDonald, N. E. (2015). Vaccine hesitancy: Definition, scope and determinants. Vaccine, 33(34), 4161–4164. https://doi.org/10.1016/j.vaccine.2015.04.036

Miko, D., Costache, C., Colosi, H. A., Neculicioiu, V., & Colosi, I. A. (2019). Qualitative assessment of vaccine hesitancy in Romania. Medicina (Kaunas, Lithuania), 55(6), 282. https://doi.org/10.3390/medicina55060282

Nair, A. T., Nayar, K. R., Koya, S. F., Abraham, M., Lordson, J., Grace, C., Sreekumar, S., Chembon, P., Swarnam, K., Pillai, A. M., & Pandey, A. K. (2021). Social media, vaccine hesitancy and trust deficit in immunization programs: A qualitative enquiry in Malappuram district of Kerala, India. Health Research Policy and Systems, 19(S2), 1-56. https://doi.org/10.1186/s12961-021-00698-x

Olson, O., Berry, C., & Kumar, N. (2020). Addressing parental vaccine hesitancy towards childhood vaccines in the United States: A systematic literature review of communication interventions and strategies. Vaccines (Basel), 8(4), 590. https://doi.org/10.3390/vaccines8040590

Paterson, P., Chantler, T., & Larson, H. J. (2018). Reasons for non-vaccination: Parental vaccine hesitancy and the childhood influenza vaccination school pilot programme in England. Vaccine, 36(36), 5397-5401. https://doi.org/10.1016/j.vaccine.2017.08.016

Pivetti, M., Melotti, G., & Mancini, C. (2020). Vaccines and autism: A preliminary qualitative study on the beliefs of concerned mothers in Italy. International Journal of Qualitative Studies on Health and Well-being, 15(1), 1754086. https://doi.org/10.1080/17482631.2020.1754086

Sethi, S., Kumar, A., Mandal, A., Shaikh, M., Hall, C. A., Kirk, J. M. W., Moss, P., Brookes, M. J., & Basu, S. (2021). The UPTAKE study: A cross-sectional survey examining the insights and beliefs of the UK population on COVID-19 vaccine uptake and hesitancy. BMJ Open, 11(6), e048856-e048856. https://doi.org/10.1136/bmjopen-2021-048856

Schwartz, J. L. (2012). New media, old messages: Themes in the history of vaccine hesitancy and refusal. The Virtual Mentor, 14(1), 50.

World Health Organization. (2019). Vaccines and immunization. https://www.who.int/health-topics/vaccines-and-immunization#tab=tab_1

World Health Organization. (2021). Global progress against measles threatened amidst COVID-19 pandemic. https://www.who.int/news/item/10-11-2021-global-progress-against-measles-threatened-amidst-covid-19-pandemic

Yalçin, S. S., Bakacak, A. G., & Topaç, O. (2020). Unvaccinated children as community parasites in national qualitative study from Turkey. BMC Public Health, 20(1), 1-17. https://doi.org/10.1186/s12889-020-09184-5

ABOUT THE AUTHORS

This paper was collaboratively done by five Critical Inquiry: Qualitative Research students in the Fall of 2021 during their course work in the BSN-AE Nursing Program at Kwantlen Polytechnic University in British Columbia, Canada.