COVID-19 remains a serious threat to public health. In the United States, 70 % of the population is considered fully vaccinated, a level too low to create "herd" immunity. Thus, vaccine hesitancy remains a current problem for public health and is an important constraint on mitigating future pandemics. This study evaluates three components of health messaging that might be targeted for counteracting hesitance, vested interests, reactance, and perceived threat. Structural equation modeling of survey data from a demographically representative and politically balanced sample of 1588 U.S. residents showed that reactance was the only significant explanation for self-reported vaccination status. Its effect was stronger for conservatives, with reactance strongly and negatively influencing vaccine acceptance as a mediating factor. The same path was significant for liberals but with a drastically smaller total effect. Liberals also had a small but significant direct effect of reactance on reported vaccination. These findings indicate that to encourage the highest possible acceptance, future vaccine policy and messaging must avoid threatening perceived individual freedoms and stress personal choice. We suggest such measures.
Keywords: COVID-19; Hesitancy; Politics; Reactance; Threat; Vaccine; Vested interests.
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