Vaccine confidence is higher in more religious countries.

Vaccine hesitancy is a threat to global health, but it is not ubiquitous; depending on the country, the proportion that have confidence in vaccines ranges from a small minority to a huge majority. Little is known about what explains this dramatic variation in vaccine confidence. We hypothesize that variation in religiosity may play a role because traditional religious teachings are likely to be incompatible with the specific magical/spiritual health beliefs that often undergird anti-vaccination sentiments. In analyses of publicly available data in 147 countries, we find that a country measure of religiosity is strongly positively correlated with country measures of confidence in the safety, importance, and effectiveness of vaccines, and these associations are robust to controlling for measures of human development (education, economic development, and health). The underlying mechanism needs to be examined in future research.