The Authorization of the First COVID-19 Vaccines Changed the Level and Nature of Intend to Get Vaccinated.

Despite the abundance of literature on vaccine hesitancy, how public opinion changes during and after the authorization of a new vaccine remains an open question. The COVID-19 pandemic offers a unique case since the development and roll-out of the first generation of vaccines happened at unprecedented speed. To understand how the public's intent to get vaccinated changed around the emergency authorizations of the first COVID-19 vaccines, we ran a secondary analysis of survey data that consisted of rolling cross-sections of Facebook users in 23 countries (N = 375,627) between July 2020 and April 2021. In contrast to prior longitudinal work, we did not only investigate the change in levels of the intent to get vaccinated but also in the nature of it, i.e., the change in the influence of core predictors. Moreover, our data span a longer phase than prior work and included various countries in the Global South. We found that the intent to get vaccinated decreased around the time of the authorization of the first COVID-19 vaccines before it increased again. In the composition of people who refused vaccination or were undecided, notable differences were found for age, gender, and, most importantly, trust in health authorities as information sources before, around, and after the authorization of the vaccines. We conclude that the importance of trust-inducing communication in the early phase of a vaccination campaign cannot be overstated.