The impact of online misinformation on U.S. COVID-19 vaccinations

Widespread uptake of COVID-19 vaccines is necessary to achieve herd immunity. However, surveys have found concerning numbers of U.S. adults hesitant or unwilling to be vaccinated. Online misinformation may play an important role in vaccine hesitancy, but we lack a clear picture of the extent to which it will impact vaccination uptake. Here, we study how vaccination rates and vaccine hesitancy are associated with levels of online misinformation about vaccines shared by 1.6 million Twitter users geolocated at the U.S. state and county levels. We find a negative relationship between misinformation and vaccination uptake rates. Online misinformation is also correlated with vaccine hesitancy rates taken from survey data. Associations between vaccine outcomes and misinformation remain significant when accounting for political as well as demographic and socioeconomic factors. While vaccine hesitancy is strongly associated with Republican vote share, we observe that the effect of online misinformation on hesitancy is strongest across Democratic rather than Republican counties. These results suggest that addressing online misinformation must be a key component of interventions aimed to maximize the effectiveness of vaccination campaigns.