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

"Vaccine confidence is an increasingly important global public health issue, with decreases in confidence leading to well-documented cases of disease outbreaks, setbacks to global polio eradication as well as other immunization goals, and contentious political debates in high and low-income countries alike..."

This global survey builds on previous studies of vaccines' perceived importance, safety, effectiveness, and religious compatibility. The objectives of this paper are to: respond to international calls for monitoring public confidence in immunisation; examine worldwide variation in attitudes, exploring the socio-economic determinants of vaccine attitudes; and interpret and discuss the results in the context of global immunisation and monitoring systems. The study builds on a 5-country vaccine confidence survey conducted in 2014 (see Related Summaries, below).

This study - in collaboration with WIN/Gallup International Association - draws from the 10-question Likert survey proposed by the World Health Organization (WHO)'s Strategic Advisory Group of Experts (SAGE) on Immunization and comprises survey responses from 65,819 individuals across 67 countries. The fieldwork was conducted between September 2015 and December 2015. Each respondent was asked to rate - on the 5-point Likert scale: strongly agree, tend to agree, do not know, tend to disagree, strongly disagree - the extent to which they agreed with 4 statements pertaining to vaccination: "vaccines are important for children to have"; "overall I think vaccines are safe"; "overall I think vaccines are effective"; and "vaccines are compatible with my religious beliefs".

Overall sentiment towards vaccine importance is positive across all 67 countries; however, there is wide variability between countries and across world regions. (Click here for an interactive, country-specific data viewer.) Confidence in vaccine safety is less positive, particularly in the European region, which has 7 of the 10 least confident countries, with 41% of respondents in France and 36% of respondents in Bosnia & Herzegovina reporting they disagree that vaccines are safe, followed by Russia (28%) and Mongolia (27%), with Greece, Japan, and Ukraine not far behind (25%). This is compared to a global average of 12%. Vaccines are perceived to be safe across countries surveyed in the South East Asian region (Bangladesh, Indonesia, Thailand, and India). With the notable exceptions of France and Italy - which have high levels of safety-based vaccine skepticism - Western and Northern European countries express less concern about vaccine safety than Eastern and Southern European countries. Spatial contiguity is not limited to Europe: the United States, Canada, and Mexico have higher levels of safety concerns than countries in South America, and China, Mongolia, Japan, Hong Kong, and Vietnam all have high fractions of negative responses. Males are less likely to think vaccines are important than females (odds ratio [OR] 0.86, 95% confidence interval [CI] 0.80 to 0.94), but there are no significant differences between the sexes for vaccine safety, effectiveness, or religious compatibility.

According to the authors, the more negative vaccine-safety perceptions in the European region are striking, particularly given widespread access to vaccines. The research thus stresses the emerging shift away from access to vaccines as the primary barrier to vaccination in many countries, a finding supported by other European studies, such as a review which finds vaccine side-effects and vaccine safety as the most commonly-cited amongst the public (Yaqub et al., 2014). The extreme negative sentiment around vaccine safety reported in France builds upon multiple strands of vaccine controversies and distrust that have evolved in France over the past 2 decades. These include controversies relating to side effects of the hepatitis B vaccine, physician-led petitions disputing the hexavalent vaccine for infants and the human papillomavirus (HPV) vaccine, and hesitancy amongst general practitioners, and many reporting doubt in immunisation programmes.

Although in certain countries particular religious groups were more vaccine-sceptical than other groups, no one religion was globally predictive of negative attitudes. Many countries are found to have strong faith-compatibility issues, most notably in Thailand and Mongolia. Religious fundamentalism has been cited as a major factor of polio refusal in Afghanistan, Nigeria, and Pakistan, which have moderate religious objection rates within the Muslims sampled (3%, 12%, and 14%, respectively); however, faith type alone is not linked to vaccination issues and interacts with other national factors: Saudi Arabia - a country with 100% Muslim respondents - has a very low religious objection rate (2%). As Grabenstein notes in a review of religious teachings and vaccination (Grabenstein, 2013), there are few religious groups, with the exception of Christian Scientists, whose official religious texts explicitly reject immunisation. Grabenstein's review found that most vaccine reluctance and refusal, sometimes attributed to religious beliefs, is more related to vaccine safety or other personal beliefs that are shared across a social network within a religious congregation. Political, cultural, and historical context modifies the effect of religion rather than being specifically tied to theological beliefs. The survey's findings - showing varying views within one religious group - also suggest that different political, cultural, and historical contexts can additionally influence vaccine opinion. This indicates that the effect of faith on vaccine attitudes is dependent on local context, and that these attitudes are not necessarily driven by religious doctrine in itself, but mediated by political, socio-cultural, and other factors.

According to the paper, these findings can help inform public health agendas by, first of all, highlighting national and regional variations in attitudes towards vaccines. One pattern shared by diverse countries worldwide is a worrying gap between high confidence in vaccine importance yet lower confidence in safety, identifying at-risk countries whose vaccine acceptance may be more precarious than previously thought. Meanwhile, factors such as religion, which past research shows to be crucial in some sub-populations, display no consistent pattern at the global scale, emphasising the importance for future research of understanding the local drivers of vaccine confidence in more detail. The authors stress the importance of identifying and monitoring hesitant groups: small clusters of non-vaccinators can have disproportionately adverse effects on herd immunity and epidemic spread.

"This study can hence be used as a baseline with which to compare future surveys on vaccine hesitancy (thus monitoring the evolution of vaccine-hesitancy) and with which future surveys can be tailored to identify hesitancies toward particular vaccinations and investigate local drivers of hesitancy. The findings herein, coupled with the recent literature on vaccine confidence, point to the importance of continued worldwide monitoring of confidence in vaccines, so that policymakers can monitor the effects of their interventions on immunization attitudes and acceptance and more effectively allocate resources to address hesitancy issues and build confidence."