Towards a More Critical Public Health Understanding of Vaccine Hesitancy: Key Insights from a Decade of Research

"[T]here is a need to incorporate more social science research within the field of vaccine hesitancy, an area that has generally been dominated by biomedical thinking."

With global outbreaks of vaccine-preventable diseases such as measles and diphtheria, as well as high rates of public questioning and/or rejection of COVID-19 vaccination, vaccine hesitancy has been placed firmly on the global public health agenda. Against this backdrop, over the last decade, the authors of this commentary have conducted various qualitative, social science studies, including various Cochrane systematic reviews of qualitative research globally, systematic reviews of qualitative research in Africa, and primary research studies in South Africa. Here, they share seven key overarching insights they have gained about this complex phenomenon from the varying studies, with the hope of providing a platform for further engagement on - and ultimately fostering a more critical public health understanding of - vaccine hesitancy.

The seven insights comprise the following:

1. The relationship between vaccine knowledge and hesitancy is complex and may operate in multiple directions. One of the most persistent assumptions in the vaccine hesitancy literature is that having sufficient medical facts about the benefits and value of vaccines will lead to greater acceptance of them. However, the authors' research shows that some of those who are hesitant about vaccination have very sophisticated understandings of vaccines, including their composition, functioning, and potential risks. In addition, the complexity of the relationship between vaccination knowledge and acceptance "raises questions about what we should be trying to achieve through our public health interventions. That is, should we be seeking to raise awareness about, and compliance with, vaccination? Or is building science literacy so people can make informed decisions and consent for vaccination important?"
2. Vaccine hesitancy is driven by multiple socio-political forces. For example, the authors' research reveals that vaccine hesitancy may be influenced by: people's broader worldviews about health and illness; the vaccination ideas and practices of people's social networks and communities; wider political issues and relations of power and their impact on people's trust (or distrust) in those associated with vaccination programmes; poverty and marginalisation; and people's access to and experiences of vaccination services and frontline healthcare professionals. However, more individualistic and biomedical approaches continue to dominate vaccine hesitancy research and interventions to address it. One reason is that decision-making by policy-makers and assessments by donor agencies continue to demand simple and reproducible interventions. "However, if we hope to effectively understand vaccine hesitancy, prioritizing more in-depth qualitative research approaches is essential and urgent. So too is the need to prioritize more multi-faceted and complex strategies that target the social determinants of vaccine hesitancy, along with the provision of education and risk communication."
3. Vaccine hesitancy may be many things, rather than a single phenomenon. The authors have observed that local contexts and framings matter greatly. For example, their global systematic review highlighted that a worldview informed by neoliberal discourses may be a significant driver of vaccine hesitancy for parents from higher-resource settings, whereas for many parents from lower-resource settings, their experiences of social exclusion may be a major contributor to vaccine hesitancy. However, for the most part, vaccine hesitancy still tends to be spoken about, and intervened upon, in ways that insufficiently appreciate this (and other types of) diversity. The diverse nature of vaccine hesitancy means that "single and one-size-fits-all strategies are unlikely to have much traction. Rather, there is a need for multi-component interventions that are tailored to local socio-political contexts, and which target the specific reasons driving vaccine hesitancy in those contexts."
4. Vaccine hesitancy may be an ongoing "process", rather than a fixed "stance". "Another common assumption in the vaccine hesitancy literature is that vaccine decisions comprise a more or less fixed position or stance that individuals arrive at in a linear way and at a discrete point in time.... However,...research has consistently demonstrated that...people's views about vaccination are frequently developed through ongoing interacting and relating, and as such are so often characterized by indeterminacy and an ever-present potential for redevelopment. Importantly, ...this procedural nature of vaccination...opens up important opportunities - but at the same time challenges - for tracking and responding to vaccine hesitancy..."
5. Vaccine hesitancy may sometimes be about a "striving", rather than a "resisting". Stigmatising labels (e.g., "selfish") are often used to describe the vaccine hesitant, which can make it challenging for people with differing vaccination views to have civil conversations. Per the authors, one potential way out of this impasse is to appreciate the often positive motivations underpinning people's concerns about vaccines. For example, vaccine hesitancy may be about a longing for communication that is honest about vaccine risks and uncertainties and transparent about the research and policy- and decision-making surrounding vaccines. "Importantly, when one recognizes and frames vaccine hesitancies in this way, it opens up potential avenues for public health interventions that are more compassionate and nuanced, and which find ways to work together for common goods..."
6. "Distrust" as a driver of vaccine hesitancy needs to be better contextualized and disaggregated. Research has shed light on the highly variable and context-dependent nature of distrust, the reasons for it, and how it impacts vaccination views and practices. For example, with regard to the 2003-2004 polio vaccine boycott in northern Nigeria, distrust of government programmes and their impact on vaccination was embedded in a complex interplay of local processes and relationships, such as years of disproportionate poverty and inadequate public services in affected states, religious and political tensions between the northern and southern regions of the country, and a multitude of recently implemented top-down global public health initiatives in the region. In sum, the researchers have found that "distrust, its drivers, and its impact on vaccination can only be properly understood when situated within the intricacies of particular political events, relations, and processes within particular times and places....However, the notion of distrust within the vaccine hesitancy literature tends to be used in highly generalized and aggregated ways, which arguably obscures more than it reveals." Instead, they say, we need to move toward explaining why trusting relations between parents and institutions in particular contexts might break down, which could support interventions that are appropriately tailored and targeted to the specific reasons for distrust.
7. The "demand-side" versus "supply/access-side" distinction of the drivers of suboptimal vaccination may be misleading and unhelpful. The authors have learned that these two dimensions of vaccination are deeply intertwined and often interact in complex ways. For example, in their global systematic reviews on acceptance of routine childhood vaccination and human papillomavirus (HPV) vaccination for adolescents, they have found that vaccine hesitancy may be driven by undesirable features of vaccination services and delivery logistics. Fortunately, in their view, there have been trends in the vaccine hesitancy literature towards collapsing the distinction. For instance, conceptual models are shifting to unpacking the behavioural and social drivers (BeSD) of vaccination, and immunisation journey frameworks are seeking to integrate so-called supply/access-side and demand-side issues. Going forward, the authors contend that "more research to better understand, and interventions to address, the interplay between different vaccination dimensions is needed."

In conclusion, the authors write: "The insights we have gained over the last decade, and reflected upon in this commentary piece, have emerged from studies that have utilized critical social science theory and qualitative research methods. These approaches have helped us to acquire in-depth knowledge about the complexities of contexts, processes, relationships, and decision-making dynamics. They have enabled us to unearth and explain vital, but often hard-to-measure, components such as power, politics, and social norms. Ultimately, it is because of these critical social science and qualitative research methodologies that we have been able to better understand, and make recommendations for responding to, the complex phenomenon of vaccine hesitancy."