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.

Correlates of support for international vaccine solidarity during the COVID-19 pandemic: Cross-sectional survey evidence from Germany.

During the COVID-19 pandemic, many residents of high-income countries (HICs) were eligible for COVID-19 vaccine boosters, while many residents of lower-income countries (LICs) had not yet received a first dose. HICs made some efforts to contribute to COVID-19 vaccination efforts in LICs, but these efforts were limited in scale. A new literature discusses the normative importance of an international redistribution of vaccines. Our analysis contributes an empirical perspective on the willingness of citizens in a HIC to contribute to such efforts (which we term international vaccine solidarity). We analyse the levels and predictors of international vaccine solidarity. We surveyed a representative sample of German adults (n = 2019) who participated in a two-wave YouGov online survey (w1: Sep 13-21, 2021 and w2: Oct 4-13, 2021). International vaccine solidarity is measured by asking respondents preferences for sharing vaccine supplies internationally versus using that supply as boosters for the domestic population. We examine a set of pre-registered hypotheses. Almost half of the respondents in our sample (48%) prioritize giving doses to citizens in less developed countries. A third of respondents (33%) prefer to use available doses as boosters domestically, and a fifth of respondents (19%) did not report a preference. In line with our hypotheses, respondents higher in cosmopolitanism and empathy, and those who support domestic redistribution exhibit more support for international dose-sharing. Older respondents (who might be more at risk) do not consistently show less support for vaccine solidarity. These results help us to get a better understanding of the way citizens' form preferences about a mechanism that redistributes medical supplies internationally during a global crisis.

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.

Stamping the vaccine passport? Public support for lifting COVID-19 related restrictions for vaccinated citizens in France, Germany, and Sweden.

During theCOVID-19pandemic,manycountries implementedrestrictionsto limit the spread of the SARS-CoV-2 virus (e.g. travel restrictions and lockdowns).One path to loosening restrictions is to do so selectively only for vaccinated individuals (e.g. by implementing vaccine passports domestically or as a prerequisite for international travel).Setting different rules based on people's vaccination statusis howevera contentious issue among health policy experts, government officials, and the public. Our analysis focuses on the levels and correlates of public support for the lifting of restrictions for the vaccinatedin April 2021, i.e. at a time when restrictions were in place and aselective lifting of these restrictions just for the vaccinatedwas debated in Europe.We use representative quota samples of the populations of France (N = 1,752), Germany (N = 1,759), and Sweden (N = 1,754). We find that a slight plurality support lifting restrictions for the vaccinated in France and Germany but not in Sweden. Vaccine hesitancy emerges as strong predictor of opposition to such a policy. Additionally, individuals who are already vaccinated (in France and Germany) and who are higher in risk-seeking express more support for the lifting of restrictions for the vaccinated. We discuss implications for the debate on vaccine passports.

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.

Shifting medical guidelines: Compliance and spillover effects for revised antibiotic recommendations.

RATIONALE: Experts have recently argued that guidelines to take the full course of antibiotics are due for revision, instead recommending that patients stop when they feel better. It is unknown how communicating revised guidelines from medical experts about how long to take a course of antibiotics will affect beliefs, behavior, and trust in guidelines more generally. OBJECTIVE: This study seeks to understand how revisions to long standing advice impacts the beliefs, behavior, and trust toward such guidelines from medical experts. METHOD: In a pre-registered experiment, we use a national sample of UK participants (N = 1,263) to test the effects of a message that reverses the prior full-course guideline (versus a status quo message to take the full course). We also test a secondary intervention that emphasizes that medical guidance and evidence may change over time. RESULTS: Early stoppage messages significantly shifted personal beliefs and perceived expert consensus about early stoppage (a shift of 16%, 95% CI: 13.8% to 17.9%, p <.001) and behavioral intent (a shift of 19%, 95% CI: 15.3 to 21.8%, p < .001) in the intended direction. Yet, the new guideline also slightly decreased acceptance of uncertainty about future guidelines (a decrease of 2%, 95% CI: 0.2% to 3.1%, p = .022) and general intention to comply with other guidelines in the future (a decrease of 6%, 95% CI: 2.6% to 8.4%, p < .001); it did not affect perceptions of medical researchers' or doctors' credibility or respondents' epistemic efficacy. Prior belief about early stoppage did not moderate receptivity to messages. Notably, though, we also find receptivity to early stoppage messages was contingent on deference to experts. We find no effect of a secondary intervention that emphasizes that medical guidance and evidence may change over time. CONCLUSIONS: Overall, our findings suggest the (U.K.) public is likely to accept new guidelines that change long standing advice to take a full course of antibiotics. While respondents show wariness about further future revisions, these data do not show that changing guidelines undermines trust in the experts that produce them.

Not Just Asking Questions: Effects of Implicit and Explicit Conspiracy Information About Vaccines and Genetic Modification.

While conspiracy ideation has attracted overdue attention from social scientists in recent years, little work focuses on how different pro-conspiracy messages affect the take-up of conspiracy beliefs. In this study, we compare the effect of explicit and implicit conspiracy cues on the adoption of conspiracy beliefs. We also examine whether corrective information can undo conspiracy cues, and whether there are differences in the effectiveness of corrective information based on whether a respondent received an explicit or implicit conspiracy cue. We examine these questions using a real-world but low-salience conspiracy theory concerning Zika, GM mosquitoes, and vaccines. Using a preregistered experiment (N = 1018: https://osf.io/hj2pw/), we find that both explicit and implicit conspiracy cues increase conspiracy beliefs, but in both cases corrections are generally effective. We also find reception of an explicit conspiracy cue and its correction is conditional on feelings toward the media and pharmaceutical companies. Finally, we find that examining open-ended conspiracy belief items reveals similar patterns, but with a few key differences. These findings have implications for how news media cover controversial public health issues going forward.

Numeracy and the Persuasive Effect of Policy Information and Party Cues.

Numeric political appeals represent a prevalent but overlooked domain of public opinion research. When can quantitative information change political attitudes, and is this change trumped by partisan effects? We analyze how numeracy-or individual differences in citizens' ability to process and apply numeric policy information-moderates the effectiveness of numeric political appeals on a moderately salient policy issue. Results show that those low in numeracy exhibit a strong party-cue effect, treating numeric information in a superficial and heuristic fashion. Conversely, those high in numeracy are persuaded by numeric information, even when it is sponsored by the opposing party, overcoming the party-cue effect. Our results make clear that overlooking numeric ability when analyzing quantitative political appeals can mask significant persuasion effects, and we build on recent work advancing the understanding of individual differences in public opinion.