Exploring Pathways for Building Trust in Vaccination and Strengthening Health System Resilience

Trust in vaccination arises from the interactions among experiences with the health system, various forms of communication, and social capital - both external and internal to communities. Such trust is critical to generate and maintain demand for vaccines in low- and middle-income countries (LMICs). However, there is little documentation on how health system insufficiencies affect trust in vaccination and the process of re-building trust once it has been compromised (e.g. by an anti-vaccine communication campaign). In this paper, Sachiko Ozawa, Ligia Paina, and Mary Qiu reflect on how disruptions to immunisation systems can affect trust in vaccination and can compromise vaccine utilisation. They then explore key pathways for overcoming system vulnerabilities in order to restore trust, to strengthen the resilience of health systems and communities, and to promote vaccine utilisation.

Ozawa, Paina, and Qiu explain that, "While the qualitative and quantitative system dynamics models published thus far on immunization acknowledge trust as a dynamic variable, they do not distinguish between the trust in the health system and trust in vaccination, therefore assuming that they act in similar ways. However, this may not be the case on the ground, where immunization program managers could struggle with consequences of trust arising from both vaccination and health system sources, which could exacerbate the challenges associated with these systems, particularly in low-resource settings. Furthermore, they generally do not specify how trust is conceptualized (i.e. at the individual or at an aggregate level) and assume that the sole source for trust is the effectiveness of a health center and that there is linear relationship between health center effectiveness, trust, and demand for immunization..."

System dynamics includes both quantitative and qualitative approaches (i.e., stock and flow diagrams, and causal loop diagram (CLDs), respectively), which can be implemented in more or less participatory ways. Utilising secondary data and a review of the literature, the authors developed a CLD to map the determinants of building trust in immunisations. In doing so, they used the recommended notation from the systems dynamics literature to mark polarity, directionality of causal relationships, and feedback. Figure 1 in the paper (and above) presents the full CLD. The authors propose that the health system and immunisation system utilisation are directly influenced by trust, and the respective pathways of influence are illustrated in the central core of the diagram. Trust in the health system is shaped by positive and negative messages about the health system. Similarly, trust in vaccination is influenced by the messages about vaccines that can arise from both within and outside the community.

Using the CLD, Ozawa, Paina, and Qiu devised 3 scenarios to illustrate common vulnerabilities that compromise trust and pathways to strengthen trust and utilisation of vaccines. They then examined spill-over effects, interactions, and other dynamics in the CLD to counter these vulnerabilities. The scenarios are, in brief:

1. Poor health systems readiness as a result of a shock to the health system - Critical events, such as the Ebola crisis or political conflict whose shocks ripple through the health system and ultimately affect service delivery, can exacerbate weaknesses of a health system. As distrust in the health system builds, this in turn generates negative messages about the health system, which again impacts utilisation. The CLD illustrates that restoring health system readiness is one of the remedies to rebuilding trust. Demonstrating this responsiveness through immunisation campaigns that ensure immunisations reach children outside of the facility could help to maintain trust in vaccination. Community-level communication and messaging - perhaps tapped through community engagement - is another approach.
2. Anti-vaccine messages - Vaccine myths and negative media reduce utilisation of vaccines, which further increases distrust. Low utilisation of vaccines may continue to reinforce myths within communities. The CLD suggests 2 possible critical junctures to reverse or mitigate the effects of anti-vaccine messages: (i) The negative messages could, in certain instances, be countered by increasing positive messages about vaccines, though it may be essential to integrate this strategy as part of a broader package of multi-component interventions to counter reduced utilisation. (ii) It can be helpful to increase the numbers of those who have positive experiences with vaccines, so that vaccine myths decreases and distrust reduces.
3. The role of social capital - "Social capital is important for community resilience - the greater the social capital in a context in which services are satisfactory, the less a community would be impacted by negative messages. With social capital, communities would also have a common voice to raise concerns to ensure accountability of healthcare services. The positive feedback loops...build on community solidarity and are essential in building system resilience." Social capital can be built, for example, through the creation of local groups that bring collectively minded individuals together with positive experiences; this can allow for greater advocacy and the voicing of information and experiences. Bridging such groups across communities and with higher-level policymakers can facilitate greater immunisation and health system readiness - driving improved experiences and, in turn, positive information dissemination.

Having identified multiple routes through which trust in vaccination can be gained or lost and highlighting key vulnerabilities within health systems and communication channels, the authors identify key areas to build resilience:

• "Understanding major information and communication channels and how to leverage them.
• Developing effective communication strategies at all levels, to ensure that accurate information about vaccines and the health system flow from the community to government/national level.
• Supporting the development of strong health systems that can rapidly respond to crises.
• Developing high levels of positive social capital within communities on the premise that 'social capital is considered not only as just protective against the impact of poverty, but also an independent predictor of child health'."

The paper suggests avenues for future research to break down the concepts presented here, and then outlines implications for policymakers. "For example, development of crisis mitigation strategies could be important to prepare communities for future health system shocks. Creation of improved communication channels relating to health systems and vaccines, appropriate to local context, would be important to build trust in vaccination and health system related information. Finally, building linkages among government, media, health care workers, community leaders and community members to build trust in information about the health system and vaccination would build more resilience."

Ozawa, Paina, and Qiu conclude that this exploration "could be deepened by adapting the CLD to a particular context, where it could also be a useful local level planning tool. Restoring trust requires a careful balance between eliminating vulnerabilities and strengthening social capital and interactions among communication channels. Systems shocks cannot all be prevented or controlled - natural calamities, disease epidemics, conflict or political turmoil happen. By deliberately focusing on and building trust and social capital, health systems could become more resilient and more apt to manage these shocks and quick to recover from them."