Vaccinating across the aisle: using co-partisan source cues to encourage COVID-19 vaccine uptake in the ideological right.

Overcoming the COVID-19 pandemic in the United States will require most Americans to vaccinate against the disease. However, considerable research suggests that a significant proportion of Americans intend to forego vaccination, putting pandemic recovery at risk. Republicans are one of the largest groups of COVID-19 vaccine hesitant individuals. Therefore, identifying strategies to reduce vaccine hesitancy within this group is vital to ending the pandemic. In this study, we investigate the effectiveness of messages from co-partisan sources in reducing vaccine hesitancy. In a large (N = 3000) and demographically representative survey, we find that exposing "Middle-of-the-Road" partisans to pro-vaccine messages from co-partisan source cues reduces vaccine hesitancy. However, for those who identify as "Strong" or "Weak" partisans, we find no statistically significant differences in vaccination intentions when exposed to pro-vaccine messages from co-partisan sources. We conclude by discussing how our findings are helpful for vaccine communication efforts.

"The CDC Won't Let Me Be": The Opinion Dynamics of Support for CDC Regulatory Authority.

CONTEXT: The CDC's ability to respond to communicable disease threats has recently met significant political and legal opposition. The authors unpack the influence of political ideology on support for CDC authority, and they experimentally assess whether highlighting ideology's role in responding to health threats might bolster CDC support. METHODS: The authors fielded a demographically representative online survey experiment to 5,483 US adults. They assessed the sociopolitical correlates of CDC attitudes via multivariate regression analyses limited to a study-wide treatment group. Additionally, they tested the effectiveness of their experimental treatments via multivariate models that interact indicators of stimulus exposure with political ideology. FINDINGS: Although most Americans support the CDC's role in responding to health crises, self-identified conservatives are significantly less likely to do so. This effect holds when accounting for respondents' limited government and anti-expert attitudes, which the authors replicated in nationally representative data. Encouragingly, though, emphasizing the CDC's role in combating the spread of COVID-19 is associated with significantly stronger levels of support on the ideological right. CONCLUSIONS: Efforts to communicate the CDC's importance in responding to health threats can help bridge existing ideological divides and might create an incentive for policy makers to codify the agency's regulatory powers.

How Localized Outbreaks and Changes in Media Coverage Affect Zika Attitudes in National and Local Contexts.

Public opinion researchers often find changing attitudes about pressing public health issues to be a difficult task and even when attitudes do change, behaviors often do not. However, salient real-world events have the ability to bring public health crises to the fore in unique ways. To assess the impact of localized public health events on individuals' self-reported behavior, this paper examines Floridians' intentions to take preventative measures against the Zika virus before and after the first locally transmit- ted case of Zika emerged in Florida. We find that local and national media coverage of Zika increased significantly following its first transmission in the U.S. Critically, we also find that Floridians surveyed after this increase in media coverage were more likely to pay attention to Zika-related news, and self-report intentions to take protective action against the virus. These results suggest that behavioral intentions can shift as health threats become more proximate.

Which foreign vaccine should the government purchase in a pandemic? Evidence from a survey experiment in the United States.

BACKGROUND: For many countries confronting a future pandemic, the initial vaccines available will come from abroad. Public hesitancy to receive these foreign vaccines is important, as it may create an incentive for governments to forego procuring them for public use. We investigate the influence of the vaccine's country of origin on public support for government procurement during the early stages of a pandemic and examine whether endorsements from the WHO can mitigate such biases. METHODS: In the summer of 2023, we carried out a survey experiment of 1,110 U.S. residents where we asked respondents to rate their support for vaccine purchasing policies for 20 hypothetical vaccines (13,320 evaluations). We varied the vaccine's country of origin and its endorsement status from the WHO, while also randomizing other vaccine attributes. RESULTS: Compared to foreign vaccines from countries Americans see favorable (e.g., Germany, the United Kingdom), those originating from less favorable countries (e.g., China, Russia), garnered lower support for government procurement. Our causal mediation analysis indicates that this country-of-origin effect is primarily driven by participants' sentiments toward the vaccine. Surprisingly, WHO endorsement does little to mitigate the effect of the vaccine's country of origin. These findings are consistent across various sample subsets and considerations of vaccine quality. CONCLUSION: Our study advances previous work on vaccine country-of-origin effects by assessing its impact on policy preferences for procuring initial vaccines from overseas (as opposed to uptake intentions), identifying a mechanism by which vaccine favoritism occurs, and documenting that neither personal disease susceptibility nor vaccine quality fully mitigates country of origin effects. We conclude by discussing why the study of "vaccine diplomacy" ought to not only include interstate dynamics governing vaccine purchasing and availability but also consider vaccine-producing countries' more general reputations.

Investigating how historical legacies of militarized violence can motivate COVID-19 vaccine hesitancy: Evidence from global dyadic survey.

BACKGROUND: In almost all countries, COVID-19 vaccines available for public use are produced outside of that country. Consistent with recent social science research, we hypothesize that legacies of violent conflict from vaccine-producing against vaccine-consuming countries may motivate vaccine hesitancy among people in targeted countries that purchase vaccines produced by the erstwhile aggressor. METHODS: Our analyses draw on data from the Correlates of War project and a large, representative survey of 18,291 adults that asked respondents in 16 countries to self-report their attitudes toward COVID-19 vaccines originating from 12 potential vaccine-producing countries in December 2020 (184 country-pairs, 208,422 ratings). For the main analysis, we used random-effect linear probability models and turned to Bayesian Model Averaging to probe the robustness of the main findings. RESULTS: We demonstrate that elevated levels of historical violence between vaccine-producing and vaccine-consuming countries are associated with increased negative feelings toward a COVID-19 vaccine produced by the vaccine producer. CONCLUSION: Global vaccine hesitancy may result, at least in part, from public perceptions of historical conflict between vaccine-producing and vaccine-consuming countries. These results can help public health practitioners better preempt and adjust for cross-national vaccine resistance.

Imperfect messengers? An analysis of vaccine confidence among primary care physicians.

BACKGROUND: Growing narratives emphasize using primary care physicians as leaders in efforts to promote COVID-19 vaccination among the vaccine hesitant. Critically however, little is known about vaccine confidence among primary care physicians themselves. The objective of this study was to assess both physician confidence that in general, vaccines are safe, effective, and important, as well as physician confidence in each COVID-19 vaccine in the United States. METHODS: We rely on data from a national survey of primary care physicians conducted from May 14-May 25, 2021. We assess the influence of demographic, social, and political factors on physician beliefs that in general, vaccines are safe, effective, and important, as well as physician confidence in the safety of the Moderna, Pfizer, and Johnson & Johnson COVID-19 vaccines. RESULTS: 10.1% of primary care physicians do not agree that, in general, vaccines are safe, 9.3% do not agree they are effective, and 8.3% do not agree they are important. While 68.7% of physicians were 'very confident' in the safety of the Moderna vaccine and 72.7% were 'very confident' in the safety of the Pfizer vaccine, only 32.1% of physicians were 'very confident' in the safety of the Johnson & Johnson COVID-19 vaccine. CONCLUSION: A troubling proportion of primary care physicians lack high levels of vaccine confidence. These physicians may not be well positioned to actively promote COVID-19 vaccination even as political and media narratives push physicians to lead this effort. Interventions aimed at improving vaccine confidence among some physicians may be needed so that all physicians can fulfill needed roles as trusted vaccine communicators.

Quantifying the effect of Wakefield et al. (1998) on skepticism about MMR vaccine safety in the U.S.

BACKGROUND: Efforts to trace the rise of childhood vaccine safety concerns in the US often suggest Andrew Wakefield and colleagues' retracted 1998 Lancet study (AW98)-which alleged that the MMR vaccine can cause children to develop autism-as a primary cause of US vaccine skepticism. However, a lack of public opinion data on MMR safety collected before/after AW98's publication obscures whether anecdotal accounts are indicative of a potentially-causal effect. METHODS: We address this problem using a regression discontinuity framework to study change in monthly MMR injury claims (N = 74,850; from 1990-2019) from the Vaccine Adverse Events Reporting System (VAERS) to proxy concern about vaccine safety. Additionally, we suggest a potential mechanism for the effect of AW98 on vaccine skepticism, via automated sentiment analyses of MMR-related news stories (N = 674; from 1996-2000) in major television and newspaper outlets. RESULTS: AW98 led to an immediate increase of about 70 MMR injury claims cases per month, averaging across six estimation strategies (meta-analytic effect = 70.44 [52.19, 88.75], p < 0.01). Preliminary evidence suggests that the volume of negative media attention to MMR increased in the weeks following AW98's publication, across four estimation strategies (meta-analytic effect = 9.59% [3.66, 15.51], p < 0.01). CONCLUSIONS: Vaccine skepticism increased following the publication of AW98, which was potentially made possible by increased negative media coverage of MMR. SIGNIFICANCE: Childhood vaccine skepticism presents an important challenge to widespread vaccine uptake, and undermines support for pro-vaccine health policies. In addition to advancing our understanding of the previously-obscured origins of US vaccine skepticism, our work cautions that high-profile media attention to inaccurate scientific studies can undermine public confidence in vaccines. We conclude by offering several recommendations that researchers and health communicators might consider to detect and address future threats to vaccine confidence.

Applications & critical reflections on the VANMaN taxonomy.

The VANMaN model provides social scientists with a parsimonious framework for understanding and addressing a wide range of fraudulent health claims, and their behavioral consequences. In this commentary, I demonstrate VANMaN's ability to generate testable corrective health communication messages by applying it to an emerging conspiracy theory; the idea that tick-borne illnesses are the result of failed military bio-terrorism research. I then offer critical reflections on VANMaN that social scientists ought to keep in mind when consulting the model. First, I discuss the possibility that VANMaN may have difficulty taxonomizing certain fraudulent claims that originate from well-intentioned sources. Second, I consider the possibility that some actors might exploit this taxonomy to further advance fraudulent claims. I conclude by noting that, while VANMaN is both intuitive and generative, it should nevertheless be seen as a "living" taxonomy; subject to adaptation in response to new public health challenges.

The pervasiveness and policy consequences of medical folk wisdom in the U.S.

Medical folk wisdom (MFW) refers to widely held, but factually inaccurate, beliefs about disease, immunity, pregnancy, and other medically-relevant topics. Examples include the idea that fasting when feverish ("starving a fever") can increase the pace of recovery, or that showering after sex can prevent pregnancy. The pervasiveness of MFW, and whether or not it-like other forms of medically-relevant misinformation-shapes Americans' health behaviors and policy preferences is an important and under-studied question. We begin this research by proposing and validating a novel measure of MFW; including a short-form scale suitable for administration in public opinion surveys. We find that nearly all Americans-irrespective of socio-economic status, political orientation, and educational background-endorse at least some aspects of MFW. Concerningly, and consistent with the idea that folk wisdom challenges scientific expertise, we additionally find that those highest in MFW tend to place less value on medical expertise and the role experts play in shaping health policy. However, this skepticism does not appear to translate to peoples' health actions, as MFW appears to have an inconsistent effect on public participation in healthy behaviors.

Explaining science funding attitudes in the United States: The case for science interest.

While most Americans recognize the importance of funding scientific research, many are satisfied with status quo funding, and only a minority see a need for increased federal support. This poses a potential challenge to scientists' abilities to address complex policy problems, like climate change. Previous correlational research suggests that public opposition to science funding is (at least in part) the result of low levels of knowledge about the basics of science. Leveraging panel data from two nationally representative studies (2008-2014), I show that people who become more interested in science over time but not those who become more knowledgable are more likely to favor increasing public support for scientific research. These results hold when controlling for other known correlates of science funding attitudes (e.g. political ideology, religiosity). I conclude by discussing the potential benefits of prioritizing science communication and science education efforts to increase public science interest.

Parent psychology and the decision to delay childhood vaccination.

OBJECTIVE: The study of vaccine hesitancy identifies parental decisions to delay childhood vaccinations as an important public health issue, with consequences for immunization rates, the pursuit of nonmedical exemptions in states, and disease outbreaks. While prior work has explored the demographic and social underpinnings of parental decisions to delay childhood vaccinations, little is known about how the psychological dispositions of parents are associated with this choice. We analyze public opinion data to assess the role of psychological factors in reported parental decisions to delay childhood vaccination. RATIONALE: We anticipate that parents with certain psychological characteristics will be more likely to delay childhood vaccination. Specifically, we explore the roles of conspiratorial thinking, dispositions towards needle sensitivity, and moral purity; expecting that parents with high levels of any of these characteristics will be more likely to delay vaccinating their children. METHOD: In an original survey of 4010 American parents weighted to population benchmarks, we asked parents about delay-related vaccination behavior, demographic questions, and several psychological batteries. We then developed a vaccination delay scale and modeled delay as a function of conspiratorial thinking, needle sensitivity, moral purity, and relevant demographic controls. We then re-specified our models to look specifically at the predictors of delaying HPV vaccination, which has a low uptake rate in the United States. RESULTS: Controlling for other common predictors of hesitant behavior, we find that parents with high levels of conspiratorial thinking and needle sensitivity are more likely to report pursuing alternative vaccination schedules. When analyzing the specific decision by parents to delay HPV vaccination, we find that tendencies towards moral purity and, in turn, sexual deviance are also associated with vaccine seeking behavior. CONCLUSION: Parental decisions to delay childhood vaccinations are an important public health concern that are associated with conspiratorial thinking and needle sensitivity.

Knowing less but presuming more: Dunning-Kruger effects and the endorsement of anti-vaccine policy attitudes.

OBJECTIVE: Although the benefits of vaccines are widely recognized by medical experts, public opinion about vaccination policies is mixed. We analyze public opinion about vaccination policies to assess whether Dunning-Kruger effects can help to explain anti-vaccination policy attitudes. RATIONALE: People low in autism awareness - that is, the knowledge of basic facts and dismissal of misinformation about autism - should be the most likely to think that they are better informed than medical experts about the causes of autism (a Dunning-Kruger effect). This "overconfidence" should be associated with decreased support for mandatory vaccination policies and skepticism about the role that medical professionals play in the policymaking process. METHOD: In an original survey of U.S. adults (N = 1310), we modeled self-reported overconfidence as a function of responses to a knowledge test about the causes of autism, and the endorsement of misinformation about a link between vaccines and autism. We then modeled anti-vaccination policy support and attitudes toward the role that experts play in the policymaking process as a function of overconfidence and the autism awareness indicators while controlling for potential confounding factors. RESULTS: More than a third of respondents in our sample thought that they knew as much or more than doctors (36%) and scientists (34%) about the causes of autism. Our analysis indicates that this overconfidence is highest among those with low levels of knowledge about the causes of autism and those with high levels of misinformation endorsement. Further, our results suggest that this overconfidence is associated with opposition to mandatory vaccination policy. Overconfidence is also associated with increased support for the role that non-experts (e.g., celebrities) play in the policymaking process. CONCLUSION: Dunning-Kruger effects can help to explain public opposition to vaccination policies and should be carefully considered in future research on anti-vaccine policy attitudes.