Vaccine intent varies significantly across countries and over time. Across countries, there are notable disparities in intent to vaccinate. Regarding time, intent has recently reached an all-time high.
BackgroundAt present, evidence is inconclusive regarding what factors influence vaccine intent, and whether there are widespread disparities across populations and time. The current study provides new insights regarding vaccine intent and potential differences across 23 countries and over time. MethodsOur data come from a unique longitudinal survey that contains responses from Facebook users (N=1,425,172) from the 23 countries from four continents collected in 18 waves from July 2020 through March 2021. ResultsWe find that vaccine intent varies significantly across countries and over time. Across countries, there are notable disparities in intent to vaccinate. Regarding time, intent has recently reached an all-time high. Our data demonstrates that intent to vaccinate has increased as countries have deployed vaccines on larger scales with undecidedness declining. However, there are some countries where vaccine intent is stagnant and in one country - Egypt - where it seems to have declined. InterpretationsLarge numbers of citizens across the world are willing to get vaccinated. In the vast majority of countries in our sample, these were high enough to reach more conservative levels of herd immunity1 if combined with numbers of persons already infected. As such, the main barrier to vaccination is not vaccine hesitancy, but the shortage of vaccines. This sends a clear message to politicians who need to work on a quick and fair distribution of vaccine; and to scientists who need to focus their attention on understanding remaining pockets of vaccine skepticism or undecidedness and on factors that explain actual vaccine behavior, rather than intent.