Understanding the Behavioural and Social Drivers of Vaccine Uptake WHO Position Paper - May 2022

"The BeSD tools are field-tested, validated and user-friendly; they can provide standardized data on the modifiable reasons for low vaccine uptake, guide the planning of vaccine programmes at subnational, national, regional, and global levels, and inform continuous learning and improvement."

Decision-makers on immunisation policy, programme managers, and partners in global eradication (e.g., polio) initiatives need to understand the underlying causes of under-vaccination. The behavioural and social drivers (BeSD) of vaccination are defined as beliefs and experiences specific to vaccination that are potentially modifiable to increase vaccine uptake. In line with the World Health Organization (WHO)'s mandate to provide guidance to Member States on health policy matters, this WHO position paper summarises the development of tools and indicators, published by WHO in 2022, to assess the BeSD of vaccine uptake for childhood and COVID-19 vaccination. The paper also reports the main findings of a scoping review that examined existing systematic reviews and meta-analyses on interventions to improve vaccine uptake. It makes recommendations for using the tools and resulting data to prioritise local interventions and suggests future research directions.

To support measurement of a wider range of drivers of vaccination, WHO established the Measuring Behavioural and Social Drivers of Vaccination global working group in October 2018. Members of the BeSD working group included representatives of global agencies and experts from multiple geographical regions, covering a range of behavioural and social science disciplines with practical and programmatic experience in low- and middle-income country (LMIC) settings. The BeSD working group is also linked to the global multi-partner Demand Hub and responds to the objectives of Immunization Agenda 2030 (IA2030), which emphasises commitment and demand (strategic objective 2) and coverage and equity (strategic objective 3).

This paper describes the development of the BeSD tools, a process that included evidence reviews, expert inputs, partner consultations, field testing, cognitive interviewing, and psychometric validation. The framework that guided the tools' development has 4 domains:

1. Thinking and feeling: the cognitive and emotional responses of people to vaccine-preventable diseases and vaccines;
2. Social processes: social norms about vaccination and receiving recommendations to be vaccinated;
3. Motivation: the intention, willingness, and hesitancy of people to get vaccinated; and
4. Practical issues: the experiences people have when trying to get vaccinated, including barriers faced (e.g.. accessing the clinic).

Within each of the 4 domains of the framework, the working group identified underlying constructs (themes). An example of a construct is "vaccine confidence", located in the Thinking and Feeling domain. Each construct was matched with one indicator - for example, the measure of "percentage of parents who say vaccines are important". Notably, "vaccine hesitancy" is part of the Motivation domain and is defined as "a motivational state of being conflicted about, or opposed to, getting vaccinated"; this state includes intentions and willingness. This definition replaces that given by the WHO Strategic Advisory Group of Experts (SAGE) on Immunization in 2014, where vaccine hesitancy was defined as a delay in acceptance or refusal of vaccination despite availability of vaccination services.

The BeSD tools - available in full here and at Related Summaries, below - include guides for in-depth interviews with stakeholders (qualitative tools), population surveys (quantitative tools), and a guidebook to support implementation of the tools. More specifically, the tools include:

• 4 qualitative interview guides for childhood vaccination to ensure an in-depth understanding of the experiences, perspectives, and attitudes of: a) caregivers of vaccine-eligible children; b) frontline health workers; c) community representatives; and d) vaccination programme managers. The BeSD working group field tested the interview guides with these 4 stakeholder groups in 12 countries. They can be used to understand influences such as literacy, political views, and socioeconomic status that are not captured in the BeSD childhood vaccination survey (see below).
• The 20-question BeSD childhood vaccination survey, which involved field testing, cognitive interviews, and psychometrical evaluation in LMICs. The survey, which assesses all BeSD domains, features 5 priority questions (corresponding to priority indicators) that are the best-performing questions across the 4 domains (see Table 2 in the paper). These priority questions can be used for appropriate routine or ad-hoc data collection activities.
• BeSD COVID-19 vaccination surveys and in-depth interview guides, whose development was informed by lessons learned during the field-testing of the childhood interview guides and survey. To date, several countries have used the COVID 19 vaccination tools, which were published online in an earlier format in April 2021 to meet an urgent need.
• BeSD guidebook for end-users (programme staff, and the research advisor), which summarises 3 steps: plan, investigate, and act. The guidebook promotes the importance of continuous measurement and learning by focusing on how programme planning, monitoring, and evaluation can use ongoing data collection on the key indicators. Included are templates and suggestions for simplified data analysis and reporting to facilitate use of data for planning and action.

To help programmes move from understanding the BeSD to acting on them, WHO initiated a scoping review to examine existing systematic reviews and meta-analyses on interventions to improve vaccine uptake across age groups. The literature search identified 264 reviews from January 2010 to June 2021 for screening; of these, 107 met inclusion criteria. Of the 107 reviews, only 13 reported primarily on LMICs. Based on findings from the scoping review and further inputs from experts, an overview of promising interventions relating to the 4 BeSD domains was developed and organised (see Table 3 in the paper). In short:

• In the Thinking/feeling and Motivation domains, interventions shown to increase vaccination are: campaigns to inform or educate the public about vaccination, including approaches based in the health facility or community; and dialogue-based interventions, including one-to-one counselling to encourage vaccination.
• In the Social processes domain, interventions shown to increase vaccination are: community engagement; positive social norm messages; vaccine champions and advocates; and recommendations to be vaccinated from health workers.
• In the Practical issues domain, interventions shown to increase vaccination are: reduced out-of-pocket costs; service quality improvements; reminder for next vaccine dose/recall for missed dose; onsite vaccination at work, home, and school; default appointments; incentives; and school and work requirements (mandates).

The review helped identify 3 specific needs for future efforts: (i) There is a need for more evidence on what interventions increase vaccine uptake in LMICs; (ii) a standard taxonomy and definitions of interventions to increase uptake would enable better comparability within and across programmes; and (iii) many reviews examined the effectiveness of more than one strategy together, (e.g., reminders and education). Study designs should enable a disaggregation of the impact of each component of the intervention and the magnitude of that effect.

The paper offers recommendations for countries and vaccination organisations, including:

• Regularly collect quality, standardised quantitative data using BeSD validated surveys and priority indicators, focusing on districts and subgroups with vaccination coverage gaps and inequities.
• Implement in-depth interviews using BeSD guides in prioritised subnational settings, adapting for population and purpose.
• Analyse, disaggregate, and use behavioural and social data in conjunction with other vaccination programme data: to improve programme implementation and address the reasons for low uptake and the selection of interventions to increase service quality; to decrease barriers to access; to build on positive motivations and social norms; and to advocate for resources to increase vaccine uptake.
• Conduct ongoing monitoring and evaluation to track and assess trends and patterns on BeSD priority indicators and to expand and enhance interventions to improve vaccine uptake for specific priority populations.
• Establish or strengthen partner coordination mechanisms for routine data collection and use these data to inform vaccination programme planning and implementation (including involvement of individuals with social sciences expertise and representatives from civil society and communities) and to make connections to digital listening platforms and relevant initiatives.

The paper concludes with further research priorities. For example, it may be useful to develop further survey questions to understand additional modifiable drivers of vaccination, such as the sense of social responsibility to vaccinate, or when contextual and programmatic changes occur.