The State of Vaccine Confidence 2016: Global Insights Through a 67-Country Survey

Abstract

Background: Public trust in immunization is an increasingly important global health issue. Losses in confidence in vaccines and immunization programmes can lead to vaccine reluctance and refusal, risking disease outbreaks and challenging immunization goals in high- and low-income settings. National and international immunization stakeholders have called for better monitoring of vaccine confidence to identify emerging concerns before they evolve into vaccine confidence crises.

Methods: We perform a large-scale, data-driven study on worldwide attitudes to immunizations. This survey - which we believe represents the largest survey on confidence in immunization to date - examines perceptions of vaccine importance, safety, effectiveness, and religious compatibility among 65,819 individuals across 67 countries. Hierarchical models are employed to probe relationships between individual- and country-level socio-economic factors and vaccine attitudes obtained through the four-question, Likert-scale survey.

Findings: Overall sentiment towards vaccinations is positive across all 67 countries, however there is wide variability between countries and across world regions. Vaccine-safety related sentiment is particularly negative in the European region, which has seven of the ten least confident countries, with 41% of respondents in France and 36% of respondents in Bosnia & Herzegovina reporting that they disagree that vaccines are safe (compared to a global average of 13%). The oldest age group (65+) and Roman Catholics (amongst all faiths surveyed) are associated with positive views on vaccine sentiment, while the Western Pacific region reported the highest level of religious incompatibility with vaccines. Countries with high levels of schooling and good access to health services are associated with lower rates of positive sentiment, pointing to an emerging inverse relationship between vaccine sentiments and socio-economic status.

Conclusions: Regular monitoring of vaccine attitudes - coupled with monitoring of local immunization rates - at the national and sub-national levels can identify populations with declining confidence and acceptance. These populations should be prioritized to further investigate the drivers of negative sentiment and to inform appropriate interventions to prevent adverse public health outcomes.

Keywords: Attitudes; Global immunization; Hierarchical regression; Vaccine confidence; Vaccine safety.

Fig. 1

Weighted responses to survey questions by country and WHO region Renormalized Likert responses by country and world region across the four survey statements, with mean-averaged (across all countries within a region) negative sentiment displayed (vertical grey lines). Within each statement countries are ranked by the percentage of negative responses. The European region performs poorly for vaccine importance, safety, and effectiveness-related skepticism, with Southern and Eastern European countries performing notably poorly for vaccine safety, though France and Italy are notable exceptions. The South East Asian and Western Pacific Region have high levels of religious-based vaccine incompatibility, notably in Mongolia, Vietnam, and Thailand.

Fig. 2

Vaccine confidence by world region and differences between perceived safety and importance. (A) Summary of Likert Responses by world region. (B) Pearson correlations between percentage of respondents across all countries agreeing ("strongly agree" or "tend to agree") with each statement. (C) Vaccine World map of percentage negative ("tend to disagree" or "strongly agree") survey responses to the statement "overall I think vaccines are safe". (D) Differences in the proportion of people responding that they believe vaccines are important but unsafe (with 95% confidence intervals).