Tale of three Americas: a cluster analysis on state-to-state variations in COVID-19 vaccination rates in the USA

Mass vaccination is one of the major response strategies of the US government against the COVID-19 pandemic. The vaccination rates in the USA have however been behind those of other developed countries. This study attempts to examine the factors contributing to the variations in the COVID-19 vaccination rates among different US states. Based on the results from a two-step cluster analysis and a series of ANOVAs, vaccination rates are found to be related to governor's political party affiliation, the frequency and sentiment level of governors' direct tweets to the public, governments' pandemic response policies, and state residents' big five personality traits of neuroticism, openness and extraversion. Practical recommendations were then proposed on how individual governmental jurisdictions could customise effective messaging and other tactics to persuade and facilitate their residents to receive COVID-19 vaccines.