Background Vaccine hesitancy (VH) and the global decline of vaccine coverage are a major global health threat, and novel approaches for increasing vaccine confidence and uptake are urgently needed. ‘Nudging’, defined as altering the environmental context in which a decision is made or a certain behaviour is enacted, has shown promising results in several health promotion strategies. We present a comprehensive synthesis of evidence regarding the value and impact of nudges to address VH.
Methods We conducted a systematic review to determine if nudging can mitigate VH and improve vaccine uptake. Our search strategy used Medical Subject Headings (MeSH) and non-MeSH terms to identify articles related to nudging and vaccination in nine research databases. 15 177 titles were extracted and assessed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The final list of included articles was evaluated using the Mixed Methods Appraisal Tool and the Grading of Recommendations, Assessment, Development and Evaluations framework.
Findings Identified interventions are presented according to a framework for behaviour change, MINDSPACE. Articles (n=48) from 10 primarily high-income countries were included in the review. Nudging-based interventions identified include using reminders and recall, changing the way information is framed and delivered to an intended audience, changing the messenger delivering information, invoking social norms and emotional affect (eg, through storytelling, dramatic narratives and graphical presentations), and offering incentives or changing defaults. The most promising evidence exists for nudges that offer incentives to parents and healthcare workers, that make information more salient or that use trusted messengers to deliver information. The effectiveness of nudging interventions and the direction of the effect varies substantially by context. Evidence for some approaches is mixed, highlighting a need for further research, including how successful interventions can be adapted across settings.
Conclusion Nudging-based interventions show potential to increase vaccine confidence and uptake, but further evidence is needed for the development of clear recommendations. The ongoing COVID-19 pandemic increases the urgency of undertaking nudging-focused research.
PROSPERO registration number CRD42020185817.
- public health
- health policy
- systematic review
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information.
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MDCR and JL are joint first authors.
Handling editor Seye Abimbola
Twitter @Sarah_Dlish, @shannonamcmahon
Contributors MDCR and JL conceptualised the study, designed the study methods and extracted data. MDCR wrote the first draft of the manuscript with important contributions from JL. JW acted as a data validator and contributed to the literature review. JW, KB, SLD, TB and SM contributed to the writing and edited the manuscript. SM supervised all the writing and editing of the manuscript. All authors read, critically revised the paper and approved the final version of the manuscript.
Funding This work was supported by the Bill & Melinda Gates Foundation (OPP1217275), which funded the open access publication. Under the grant conditions of the Foundation, a Creative Commons Attribution 4.0 Generic License has already been assigned to the Author Accepted Manuscript version that might arise from this submission.
Disclaimer The funders had no role in the decision to publish or in the preparation of the manuscript. The content is the responsibility of the authors and does not necessarily represent the views of any funder.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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