When experts matter: Variations in consensus messaging for vaccine and genetically modified organism safety.

Does consensus messaging about contested science issues influence perceptions of consensus and/or personal beliefs? This question remains open, particularly for topics other than climate change and samples outside the United States. In a Spanish national sample (N = 5087), we use preregistered survey experiments to examine differential efficacy of variations in consensus messaging for vaccines and genetically modified organisms. We find that no variation of consensus messaging influences vaccine beliefs. For genetically modified organisms, about which misperceptions are particularly prevalent in our sample, we find that scientific consensus messaging increases perception of consensus and personal belief that genetically modified organisms are safe, and decreases support for a ban. Increasing degree of consensus did not have consistent effects. Although individual differences (e.g. a conspiratorial worldview) predict these genetically modified organism beliefs, they do not undercut consensus message effects. While we observe relatively modest effect sizes, consensus messaging may be able to improve the accuracy of beliefs about some contentious topics.

Vaccine attributes and vaccine uptake in Hungary: evidence from a conjoint experiment.

BACKGROUND: In an ongoing public health crisis, the question of why some people are unwilling to take vaccines with particular attributes is an especially pertinent one, since low rates of vaccination mean that it will take longer for many nations to exit the coronavirus disease 2019 (COVID-19) pandemic. METHODS: In this article, we conduct a pre-registered conjoint experiment in Hungary (N = 2512), where respondents were asked about their attitudes towards hypothetical COVID-19 vaccines whose characteristics varied across a number of attributes. RESULTS: Results indicate that vaccine attributes matter for the likelihood of uptake when it comes to the prevalence of severe side effects, efficacy and country of origin. Moreover, we find that our pre-treatment measure of institutional trust moderates the effect of our treatment, as differences in vaccine attributes are larger for those with robust levels of institutional trust compared to those with weaker levels. CONCLUSION: Our findings suggest that institutional trust matters when it comes to understanding the relationship between vaccine attributes and likelihood of uptake.

Partisanship and anti-elite worldviews as correlates of science and health beliefs in the multi-party system of Spain.

In a national sample of 5087 Spaniards, we examine the prevalence of 10 specific misperceptions over five separate science and health domains (climate change, 5G technology, genetically modified foods, vaccines, and homeopathy). We find that misperceptions about genetically modified foods and general health risks of 5G technology are particularly widespread. While we find that partisan affiliation is not strongly associated with any of the misperceptions aside from climate change, we find that two distinct dimensions of an anti-elite worldview-anti-expert and conspiratorial mindsets-are better overall predictors of having science and health misperceptions in the Spanish context. These findings help extend our understanding of polarization around science beyond the most common contexts (e.g. the United States) and support recent work suggesting anti-elite sentiments are among the most important predictors of factual misperceptions.

Which vaccine attributes foster vaccine uptake? A cross-country conjoint experiment.

Why do people prefer one particular COVID-19 vaccine over another? We conducted a pre-registered conjoint experiment (n = 5,432) in France, Germany, and Sweden in which respondents rated the favorability of and chose between pairs of hypothetical COVID-19 vaccines. Differences in effectiveness and the prevalence of side-effects had the largest effects on vaccine preferences. Factors with smaller effects include country of origin (respondents are less favorable to vaccines of Chinese and Russian origin), and vaccine technology (respondents exhibited a small preference for hypothetical mRNA vaccines). The general public also exhibits sensitivity to additional factors (e.g. how expensive the vaccines are). Our data show that vaccine attributes are more important for vaccine preferences among those with higher vaccine favorability and higher risk tolerance. In our conjoint design, vaccine attributes-including effectiveness and side-effect prevalence-appear to have more muted effects among the most vaccine hesitant respondents. The prevalence of side-effects, effectiveness, country of origin and vaccine technology (e.g., mRNA vaccines) determine vaccine acceptance, but they matter little among the vaccine hesitant. Vaccine hesitant people do not find a vaccine more attractive even if it has the most favorable attributes. While the communication of vaccine attributes is important, it is unlikely to convince those who are most vaccine hesitant to get vaccinated.