Promoting COVID-19 vaccine confidence through public responses to misinformation: The joint influence of message source and message content

Objective: During the pandemic healthcare professionals and political leaders routinely used traditional and new media outlets to publicly respond to COVID-19 myths and inaccuracies. We examine how variations in the sources and messaging strategies of these public statements affect respondents’ beliefs about the safety of COVID-19 vaccines. Methods: We analyzed the results of an experiment embedded within a multi-wave survey deployed to US and UK respondents in January–February 2022 to examine these effects. We employ a test-retest between-subjects experimental protocol with a control group. Respondents were randomly assigned to one of four experimental conditions reflecting discrete pairings of message source (political authorities vs. healthcare professionals) and messaging strategy (debunking misinformation vs. discrediting mis-informants) or a control condition. We use linear regression to compare the effects of exposure to treatment conditions on changes in respondent beliefs about the potential risks associated with COVID-19 vaccination. Results: In the UK sample, we observe a statistically significant decrease in beliefs about the risks of COVID-19 vaccines among respondents exposed to debunking messages by healthcare professionals. We observe a similar relationship in the US sample, but the effect was weaker and not significant. Identical messages from political authorities had no effect on respondents’ beliefs about vaccine risks in either sample. Discrediting messages critical of mis-informants likewise had no influence on respondent beliefs, regardless of the actor to which they were attributed. Political ideology moderated the influence of debunking statements by healthcare professionals on respondent vaccine attitudes in the US sample, such that the treatment was more effective among liberals and moderates than among conservatives. Conclusions: Brief exposure to public statements refuting anti-vaccine misinformation can help promote vaccine confidence among some populations. The results underscore the joint importance of message source and messaging strategy in determining the effectiveness of responses to misinformation.