The design of Study 2.

We examine the relationships between the perception of the scientific consensus regarding vaccines, and vaccine attitudes and intentions (N total = 2,362) in the context of COVID-19 disease. Based on the correlational evidence found (Study 1), perceived scientific consensus and vaccine attitudes are closely related. This association was stronger among people who trust (vs. distrust) scientists; however, political ideology did not moderate these effects. The experimental evidence (Studies 2–3) indicates that consensus messaging influences the perception of consensus; nonetheless, the effects on vaccine attitudes or intentions were non-significant. Furthermore, message aiming at reducing psychological reactance was similarly ineffective in changing attitudes as traditional consensus message.