Negotiating vaccine acceptance in an era of reluctance

Abstract

Studies to better understand the determinants of vaccine acceptance have expanded to include more investigation into dynamics of individual decision-making as well as the influences of peers and social networks. Vaccine acceptance is determined by a range of factors, from structural issues of supply, costs and access to services, as well as the more demand-side determinants. The term vaccine hesitancy is increasingly used in the investigation of demand-side determinants, moving away from the more polarized framing of pro- and anti-vaccine groups to recognizing the importance of understanding and engaging those who are delaying vaccination, accepting only some vaccines, or who are yet undecided, but reluctant. As hesitancy is a state of indecision, it is difficult to measure, but the stage of indecision is a critical time to engage and support the decision-making process. This article suggests modes of investigating the determinants of vaccine confidence and levers of vaccine acceptance toward better engagement and dialogue early in the process of decision-making. Pressure to vaccinate can be counter-productive. Listening and dialog can support individual decision-making and more effectively inform the public health community of the issues and concerns influencing vaccine hesitancy.

Keywords: :

• immunization
• immunisation
• vaccine acceptance
• hesitancy
• trust
• confidence

Introduction

Following the 1974 World Health Assembly resolution to establish the Expanded Programme on Immunization (EPI)¹ and a subsequent global movement over the following decade working jointly with UNICEF “to achieve Universal Childhood Immunization” with the six EPI vaccines (BCG, OPV, diphtheria, tetanus, pertussis, and measles),² global immunization rates reached over 80% and childhood immunization has become a social “norm” for most populations. National immunization programs have since become embedded as a fixture in public health systems, and their performance is often considered as an indicator of how well a health system is functioning.

Immunization programs are still considered as a basic building block of any nation’s health system, but, in the face of a growing number of available vaccines—and combinations of vaccines—decision-making around which vaccines are the most appropriate, affordable and acceptable to populations has become more complex. Decision-making has not only become complex for policy-makers, but has been challenging for health professionals as well as the public. Local disease-burden and disease-risk assessments and the affordability of vaccines remain key to policy-level decision-making on which vaccines should be included in national immunization programs, but anticipating the “acceptability” of vaccines by the public has become an increasingly important factor in considering which vaccines should be given and when. Health professionals, faced with increasing questions and concerns by their clients, have also wavered in supporting the delivery and the administration of some vaccines. Public acceptability issues have been particularly contentious around: the MMR vaccine due to now-debunked UK research suggesting a link to autism³ which has had ripple effects on public confidence globally; anxieties around additives such as the preservative thiomersal in some vaccines;⁴ newer vaccines such as the HPV vaccine, which has provoked public debates over its perceived link to sexual behavior;⁵ and pandemic vaccines (e.g., H1N1) due to a combination of safety and efficacy concerns as well as low perception of disease risk.⁶

In addition to the changing vaccine landscape, the external environment has also changed significantly with widespread access to internet postings of a mix of scientifically accurate information as well as misinformation about vaccines. Social media also enables both pro- and questioning vaccine groups to organize globally, creating constituencies to influence those who are seeking more information about individual vaccines or vaccines generally.⁷ This changed communication environment has presented both opportunities as well as challenges to immunization programs, as publics are increasingly intolerant of a “take this, it’s good for you” approach and instead want full transparency of the risks of accepting—as well as not accepting—a vaccine.⁸ Publics—of which there are many, with diverse views and beliefs—want their questions answered, and their views taken seriously. This new environment has also made it more difficult for the public health and medical community to effectively communicate scientific information, including framing of risks vs. benefits of vaccines. The diverse information available on vaccines represents significant differences in how facts are interpreted and how risks vs. benefits are balanced.

Vaccine Hesitancy

Studies to better understand the determinants of vaccine acceptance have grown over the past decade to include more investigation into dynamics of individual decision-making as well as broader group dynamics, public trust and confidence in vaccines, and the influences of philosophical and religious beliefs.⁹ Research on vaccine acceptance and public trust has also recognized the importance of past experiences not only with vaccination, but with previous interactions with health providers and the health system, as influencing decisions to vaccinate.¹⁰

Another shift has been the introduction of the term “vaccine hesitancy”^11,12 into the discourse on vaccine acceptance, moving away from the more polarized framing of pro- and anti-vaccine groups to recognizing the importance of understanding and engaging those who are delaying, accepting only some vaccines, or who are indecisive and “sitting on the fence”. ¹³ Some point out the shift from a non-decision stance—i.e., accepting vaccines as a norm—toward more pro-active questioning and indecision.^13,14

The issue of vaccine hesitancy has become a recognized global concern. In March 2012, the World Health Organization Strategic Advisory Group of Experts (SAGE) on Immunization convened a Working Group to: define and assess the scope of vaccine hesitancy, “including its context-specific causes, its expression and its impact”; recommend indicators of vaccine hesitancy for monitoring; and identify strategies that have worked-or not worked—in trying to address vaccine hesitancy.¹⁵ SAGE also encouraged the Working Group to look outside of the vaccine and immunization literature to learn from other fields, such as risk and decision science, environmental science, and bioethics

At the April 2013 SAGE meeting, the Vaccine Hesitancy Working Group presented a working definition of vaccine hesitancy for discussion. The definition frames three key domains of influence: confidence, complacency and convenience. It also draws from Benin’s definition of vaccine hesitancy in the context of an analysis of mothers’ vaccine decision-making:¹⁶

“Vaccine hesitancy is a behaviour, influenced by a number of factors including issues of confidence (do not trust vaccine or provider), complacency (do not perceive a need for a vaccine, do not value the vaccine), and convenience (access). Vaccine hesitant individuals are a heterogeneous group who hold varying degrees of indecision about specific vaccines or vaccination in general. Vaccine hesitant individuals may accept all vaccines but remain concerned about vaccines, some may refuse or delay some vaccines, but accept others; some individuals may refuse all vaccines.”¹⁷

The definition carried an important additional note: “Vaccine decision-making by a caregiver or patient is a complex process with many factors influencing this both directly and indirectly. Some factors maybe more important in certain contexts than in others. Experience and circumstances may change the weight of a factor(s) in different settings.”

The Decade of Vaccines Collaboration—a time-limited initiative to support a collaborative consultation process to develop a Global Action Plan, endorsed by the World Health Assembly—also brought attention to the issue of vaccine hesitancy and made a call for more research: “to understand the factors that contribute to vaccine hesitancy” and particularly emphasized that “the impact and use of social media needs to be understood in this context.”¹⁸

Given that “hesitancy” is by nature a state of indecision and reluctance, it is difficult to measure. However, delayed vaccine acceptance can be a proxy for hesitancy, qualitative analyses on the types of questions being asked to health professionals can provide insights, and monitoring the increasingly accessible real-time online discussions about vaccines can also provide some information on the nature of concerns and beliefs.

Recent findings, for instance, from an analysis of global monitoring of media and social media on vaccines over one year (2011–2012) revealed that while 69% of the collected reports showed a positive sentiment toward vaccines, 31% were negative in tone. And, among the negative reports, more were about beliefs (e.g., philosophical, religious, naturopathy) and perceptions (e.g., of business or political motives) than about vaccine safety.¹⁹ More detailed analyses and research to understand the nature of public concerns are important to tailoring interventions to address the genuine issues affecting decisions to accept a vaccine—or not. As Prislin and colleagues conclude, “findings on socio-demographic correlates of immunization cannot explain the underlying causes of this (low vaccine acceptance) phenomenon.”²⁰

Conclusion

Although challenging, the “state” of hesitancy is a critical time to make a concerted effort to understand the issues influencing vaccine acceptance—before decisions are made, while there is still an opportunity to address any identified concerns. Some who accept vaccines—or some vaccines—remain “vaccine hesitant” about others, and the seeds of questioning remain. Dialogue and engagement around vaccine acceptance needs to be an on-going process and questions need to heard and, to the extent possible, be answered. Pressure to vaccinate can be counter-productive and prompt more, rather than less, hesitancy or even lead to vaccine refusal.²¹ The challenge for the public health community is to not alienate those who question, but to try to understand and address their concerns.²² Building public trust and restoring confidence through regular dialogue are critical to achieving sustained vaccine acceptance. Some concerns may be important cues to the public health community and can inform modes of communication or vaccine delivery that are more acceptable. The sheer gesture of listening is already a step toward public confidence in vaccines.

Disclosure of Potential Conflicts of Interest

The author has received research funding from The Bill and Melinda Gates Foundation, Novartis, and the World Health Organization (WHO).