Factors influencing Covid-19 vaccine acceptance across subgroups in the United States: Evidence from a conjoint experiment

Context dependent preferences in prestige bias learning about vaccination in rural Namibian pastoralists

Extensive work in the social sciences suggests that vaccination decisions are subject to incentives, biases, and social learning processes, including prestige bias transmission. High status figures, like doctors and public health officials, can be effective messengers for vaccination information and uptake under certain conditions. In communities where there is significant medical mistrust and less interaction with markets and formal medical systems, prestige bias social learning may operate through different channels. Here, we examine the role of prestige bias on vaccine decisions in two ethnic groups (Himba and Herero) with varying levels of market integration and experiences with formal healthcare systems. Participants completed a ranking task, comparing the influence of four prestigious individuals on vaccine decisions and a survey on medical mistrust. Using Plackett-Luce models, we compare the influence of location, ethnic affiliation, and other covariates on rankings. A multi-level model compared the influence of those within and outside one's ethnic group, as well as specialist (doctor/healer) and generalist (chief/governor) prestige figures. Results indicate changes in the rank of prestigious individuals across the rural-urban gradient. Our results demonstrate significant variability in prestige-biased social learning about vaccine decision making. Medical mistrust did not impact rankings. Contrary to previous work, we find that whether a prestigious individual is locally prominent is more important than their expertise in the relevant domain (health and healing). These findings emphasize the need for more context-specific studies of prestige bias, which can improve our understanding of healthcare decision-making and guide public health messaging across diverse contexts.

Public and health care provider attitudes, understanding, and behaviors regarding emergency use authorizations: a scoping literature review

BACKGROUND

Under Sect. 564 of the Federal Food, Drug, and Cosmetic Act, when the US Department of Health and Human Services Secretary issues a declaration based on one of four types of determinations, FDA may authorize an unapproved product or unapproved uses of an approved product for emergency use. It is unclear how much the public and health care providers understand about emergency use authorizations and how that understanding influences perceptions or behavioral intentions. The current study aimed to explore consumer and health care provider perceptions of emergency use authorizations and how promotion of emergency use authorizations has been investigated in the literature.

METHODS

We conducted a scoping review via PubMed, Embase, Web of Science, and CINAHL for original research published in English from January 1, 2012, through November 10, 2022. We conducted surveillance of the literature through March 2023.

RESULTS

We identified 13 studies reported in 14 publications that addressed public and health care provider attitudes, understanding, and behaviors with regard to products authorized under an emergency use authorization. We did not identify any articles describing research regarding the promotion of emergency use authorization products. Findings suggest gaps in understanding of emergency use authorizations, both for the public and health care providers. Findings also suggest the public and health care providers have concerns about safety or the lack of full FDA approval that may contribute to decreased willingness to receive treatments and vaccines under an emergency use authorization.

CONCLUSIONS

Future research should explore how emergency use authorizations have been promoted and how that promotion impacts public and health care provider perceptions.

Risk compensation after COVID-19 vaccination: Evidence from vaccine rollout by exact birth date in South Korea

We utilize the phased rollout of COVID-19 vaccines by exact birth date in South Korea as a natural experiment for testing risk compensation. People may resume face-to-face social activities following vaccination because they perceive lower risk of infection. Applying a regression discontinuity design based on birth date cutoffs for vaccine eligibility, we find no evidence of risk-compensating behaviors, as measured by large, high-frequency data from credit card and airline companies as well as survey data. We find some evidence of self-selection into vaccine take-up based on perception toward vaccine effectiveness and side effects, but the treatment effects do not differ between compliers and never-takers.

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.

Association between Gross National Income per capita and COVID-19 vaccination coverage: a global ecological study

BACKGROUND

Coronavirus 2019 (COVID-19) pandemic has claimed over six million lives and infected more than 650 million people globally. Public health agencies have deployed several strategies, including rolling out vaccination campaigns to curb the pandemic, yet a significant proportion of the global population has not received the COVID-19 vaccine. We assessed differences in COVID-19 vaccination coverage by Gross National Income (GNI) per capita of WHO members (i.e., countries, areas, and territories, n = 192) and by WHO member regions (n = 6).

METHODS

Using an ecological study design, we analyzed publicly available data from the WHO website merged with the World Bank's GNI per capita data. We included a total of 192 WHO members and six WHO regions in the analysis. We utilized negative binomial regression to assess the associations between the GNI per capita and COVID-19 vaccination coverage (cumulative number of persons fully vaccinated and/or received at least one dose of the vaccine per 100 population), and ANOVA test to assess the differences in vaccination coverage per WHO regions.

RESULTS

Low GNI per capita WHO members had significantly lower full vaccination coverage (aRR 0.30, 95% CI 0.22-0.40) compared to high GNI per capita WHO members. These members were also 66% less likely to receive at least one dose of the vaccine (aRR 0.34, 0.26-0.44) relative to high GNI per capita WHO members. Africa region had a significantly lower fully vaccination coverage (aRR 0.71, 95% CI 0.36-0.54) and received at least one dose of the COVID-19 vaccine (aRR 0.78, 95% CI 0.62-0.99) than Europe region. Conversely, the Western Pacific region had significantly higher fully vaccination coverage (aRR 1.40 95% CI 1.12-1.74) and received at least one dose of COVID-19 vaccines (aRR 1.40 95% CI 1.14-1.73) relative to European region.

CONCLUSION

WHO members with low GNI per capita and the African region reported significantly lower COVID-19 vaccination coverage than those with high GNI per capita or other regions. Efforts to strengthen and promote COVID-19 vaccination in low-income WHO countries and African region should be scaled up.

"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.

Evolution of preferences for COVID-19 vaccine throughout the pandemic - The choice experiment approach

In this study, we employ a choice experiment to study individual preferences for COVID-19 vaccines in the US. A unique characteristic of the microdata (N = 5671) is that the survey was conducted in five distinct waves from October 2020 to October 2021. Because of this dynamic feature, it is possible to control for evolving pandemic conditions such as the number of COVID-19 active cases, vaccination uptake, and the frequency of Google searches related to the vaccines. Furthermore, we employ a hybrid choice model to incorporate respondents' attitudes related to their perceived vulnerability to diseases, as well as their perceived health status. The hybrid choice model was extended to incorporate latent classes as well as random effects. We find that the rate of vaccinated individuals in the population actually increases the probability of vaccine hesitancy, and therefore may discourage people to get vaccinated. This may be evidence of free-riding behavior. On the other hand, the number of COVID-19 cases has a positive effect on the probability of getting vaccinated, suggesting that individuals react to the pandemic conditions by taking some protective measures. Google trend data do not seem to have a straightforward effect on the vaccination demand, but it increases consumers' willingness to pay for several vaccine characteristics. With respect to the analyzed attitudes, we find that perceived uninfectability is a significant driver of vaccine hesitancy, probably related to the frequent "natural immunity" argument. In turn, germ aversion has a positive effect on the probability of getting vaccinated as well as on the marginal willingness to pay. Finally, health status has a limited effect on whether the individual will decide to vaccinate or not.

Racial residential segregation and COVID-19 vaccine uptake: an analysis of Georgia USA county-level data

BACKGROUND

Foundational literature demonstrates that racial residential segregation results in poorer health outcomes for Black people than white people due to a variety of social determinants of health. COVID-19 vaccine uptake is important for better health outcomes, regardless of race. The COVID-19 pandemic has elevated concerns about racial health disparities but with little discussion of racial residential segregation as a predictor of disparate health outcomes. This paper investigates the relationship between racial residential segregation and COVID-19 vaccine uptake using county level data from the State of Georgia (USA).

METHODS

Using publicly available data, regression analysis is conducted for 138 of the 159 counties in Georgia USA, using a dissimilarity index that describes county level differences in racial residential segregation. The primary independent variable is Black-white differences in vaccine uptake at the county level. The analytic methods focus on a spatial analysis to support information for county level health departments as the basis for health policy and resource allocation.

RESULTS

Constructing a variable of the difference in vaccination rates between Black and white residents we find that Black-white differences in COVID-19 vaccination are most notable in the 69 most segregated of the 159 counties in Georgia. A ten-point lower segregation index is associated with an improvement in the Black-white vaccination gap of 1.5 percentage points (95% CI -0.31, -0.00). Income inequality and access to health care resources, such as access to a primary care physician, also predict Black-white differences in vaccination rates at the county level. Suggested mapping approaches of publicly available data at a state county level, provides a resource for local policy makers to address future challenges for epidemic and pandemic situations.

CONCLUSION

County level and geospatial data analysis can inform policy makers addressing the impact of racial residential segregation on local health outcomes, even for pandemic and epidemic issues.

Fears and misconceptions toward COVID-19 vaccination among Syrian population: A cross-sectional study

Background and Aims

Despite the significant milestone of vaccine discovery, the spread of misinformation and pseudoscientific claims has resulted in an increasing number of people refusing vaccination in Syria. In this study, we aimed to explore fears and misconceptions towards COVID-19 vaccines among the Syrian population.

Methods

We conducted a nationwide cross-sectional study between January and May 2022, using a convenience sample of 10,006 participants aged at least 18 years and living in Syria. We administered a validated online/paper questionnaire and conducted face-to-face interviews. We used SPSS software (version 26) for statistical analysis, assessing our data using frequency and χ 2 tests, with p < 0.05 considered statistically significant.

Results

The majority of the participants were female 6048 (60.4%), university degree holders 7304 (73%), and from urban areas 8015 (80.1%). Approximately half of the participants 5021 (50.2%) belonged to the medical sector (49% had concerns about the vaccine). Females, university degree holders, and participants with a history of symptomatic COVID-19 were more likely to have fears about the vaccines. The main concerns about the vaccines were the rapid development, fears of blood clots, and common side effects. The prevalence of some misconceptions was relatively high, such as the belief that the vaccine is an experiment or a secret plan to reduce the population. Reliable sources are crucial to fight misleading information on social media.

Conclusion

COVID-19 vaccine is key to controlling the spread, but acceptance rate is critical. High variability in vaccine acceptance and high vaccine hesitancy can affect the efforts to terminate the COVID-19 pandemic. Addressing the barriers associated with the acceptance of COVID-19 vaccination will be the cornerstone to achieving maximum vaccination coverage. It is important to consider the reasons for refusing the COVID-19 vaccine when interpreting the results of any study on vaccine attitudes among the Syrian population.

Knowledge and identity antecedents of COVID-19 vaccine status: a study of South Carolina residents

Introduction

Despite over three years of learning about SARS-CoV-2 and extensive work to develop vaccines, vaccination rates remain suboptimal, thereby preventing our society from reaching herd immunity.

Purpose

Extant literature on vaccine hesitancy led us to hypothesize that specific socio/political variables may be contributing to low vaccination rates, particularly in South Carolina.

Methods

By use of Qualtrics surveys, we collected data from people across all counties in South Carolina regarding vaccine status, plans to vaccinate, and a host of demographics.

Results

Findings revealed that those less likely to be vaccinated against COVID-19 tended to be younger, female, republican. Interestingly, COVID-19 knowledge did not appear to differ between vaccination status groups, although COVID-19 vaccine and general vaccine knowledge did differ.

Conclusions

Our results suggest that while understanding of COVID-19 was relatively similar across groups, targeted and tailored interventions aimed at enhancing the public's general and COVID-19-specific vaccine knowledge may aid efforts to reach herd immunity.

Explaining the gender gap in COVID-19 vaccination attitudes

BACKGROUND

Women have been significantly more likely than men to express hesitancy toward COVID-19 vaccination and, to a lesser extent, to refuse vaccination altogether. This gender gap is puzzling because women have been more likely to perceive higher risks from COVID-19, to approve more restrictive measures to fight the pandemic and to be more compliant with such measures.

METHODS

This article studies the gender gap in COVID-19 vaccination attitudes using two nationally representative surveys of public opinion fielded in February 2021 and May 2021 in 27 European countries. The data are analyzed using generalized additive models and multivariate logistic regression.

RESULTS

The data analyses show that hypotheses about (i) pregnancy, fertility and breastfeeding concerns, (ii) higher trust in Internet and social networks as sources of medical information, (iii) lower trust in health authorities and (iv) lower perceived risks of getting infected with COVID-19 cannot account for the gender gap in vaccine hesitancy. One explanation that receives support from the data is that women are more likely to believe that COVID-19 vaccines are unsafe and ineffective and this leads them to perceive the net benefits of vaccination as lower than the associated risks.

CONCLUSIONS

The gender gap in COVID-19 vaccine hesitancy results to a large extent from women perceiving higher risks than benefits of the vaccines. While accounting for this and other factors decreases the gap in vaccine hesitancy, it does not eliminate it completely, which suggests further research is needed.

Family size and vaccination among older individuals: The case of COVID-19 vaccine

While vaccination is generally considered efficient in protecting against transmissible diseases, the compliance is not complete in many countries. In this study, we investigate how an individual-specific factor - family size - affects the probability of getting vaccinated against COVID-19. To answer this research question, we focus on individuals above 50 years of age, who are at a higher risk of developing severe symptoms. The analysis uses the Survey of Health, Ageing and Retirement in Europe Corona wave, conducted in the summer of 2021. To identify the effect of family size on vaccination, we exploit an exogenous variation in the probability of having more than two children, due to the sex composition of two firstborns. We document that a larger family size increases the probability of receiving the COVID-19 vaccine among older individuals. This impact is economically and statistically significant. We propose several potential mechanisms behind this result and document that family size can be related to the higher probability of being exposed to the disease. This effect can be by knowing someone who tested positive for COVID-19 or had symptoms similar to it, and by network size and frequency of contact with children, before the outbreak of COVID-19.

Resistance to COVID-19 vaccination and the social contract: evidence from Italy

Confronted with stalled vaccination efforts against COVID-19, many governments embraced mandates and other measures to incentivize vaccination that excluded the unvaccinated from aspects of social and economic life. Even still, many citizens remained unvaccinated. We advance a social contract framework for understanding who remains unvaccinated and why. We leverage both observational and individual-level survey evidence from Italy to study the relationship between vaccination status and social context, social trust, political partisanship, and adherence to core institutional structures such as the rule of law and collective commitments. We find that attitudes toward the rule of law and collective commitments outside the domain of vaccination are strongly associated with compliance with vaccine mandates and incentives. Partisanship also corresponds with vaccine behaviors, as supporters of parties whose leaders criticized aggressive policies to incentivize or mandate vaccination and emphasized individual liberty are least likely to comply. Our findings suggest appeals emphasizing individual benefits may be more effective than appeals emphasizing collective responsibility.

Determinants of COVID-19 vaccine fatigue

There is growing concern that Coronavirus Disease 2019 (COVID-19) vaccine fatigue will be a major obstacle in maintaining immunity in the general population. In this study, we assessed vaccine acceptance in future scenarios in two conjoint experiments, investigating determinants such as new vaccines, communication, costs/incentives and legal rules. The experiments were embedded in an online survey (n = 6,357 participants) conducted in two European countries (Austria and Italy). Our results suggest that vaccination campaigns should be tailored to subgroups based on their vaccination status. Among the unvaccinated, campaign messages conveying community spirit had a positive effect (0.343, confidence interval (CI) 0.019-0.666), whereas offering positive incentives, such as a cash reward (0.722, CI 0.429-1.014) or voucher (0.670, CI 0.373-0.967), was pivotal to the decision-making of those vaccinated once or twice. Among the triple vaccinated, vaccination readiness increased when adapted vaccines were offered (0.279, CI 0.182-0.377), but costs (-0.795, CI -0.935 to -0.654) and medical dissensus (-0.161, CI -0.293 to -0.030) reduced their likelihood to get vaccinated. We conclude that failing to mobilize the triple vaccinated is likely to result in booster vaccination rates falling short of expectations. For long-term success, measures fostering institutional trust should be considered. These results provide guidance to those responsible for future COVID-19 vaccination campaigns.

Factors related to COVID-19 vaccine hesitancy among middle-income and low-income adults in the USA

BACKGROUND

Vaccine hesitancy has been an ongoing challenge in campaigns, especially the rapid development and approval of the COVID-19 vaccines. The goal of this study was to understand the characteristics, perceptions and beliefs of COVID-19 vaccination prior to its widespread rollout among middle-income and low-income US adults.

METHODS

Using a national sample of 2101 adults who completed an online assessment in 2021, this study examines the association of demographics, attitudes and behaviours related to COVID-19 vaccination intentions. Adaptive least absolute shrinkage and selection operator models were used to select these specific covariate and participant responses. Poststratification weights were generated using raking procedures and applied to improve generalisability.

RESULTS AND CONCLUSION

Vaccine acceptance was high at 76% with 66.9% reporting intent to receive the COVID-19 vaccine when available. Only 8.8% of vaccine supporters screened positive for COVID-19-related stress compared with 9.3% among the vaccine hesitant. However, there were more people with vaccine hesitancy who screened positive for poor mental health and alcohol and substance misuse. The three main vaccine concerns were side effects (50.4%), safety (29.7%) and mistrust of vaccine distribution (14.8%).Factors influencing vaccine acceptance included age, education, children, region, mental health and social support, threat perception, opinion of governmental response, risk exposure and prevention activities and rejecting COVID-19 vaccine concerns. The results indicated acceptance was more strongly associated with beliefs and attitudes about the vaccine than sociodemographics, which are noteworthy and may lead to targeted interventions to increase COVID-19 vaccine acceptance among subgroups who are vaccine hesitant.

How socio-institutional contexts and cultural worldviews relate to COVID-19 acceptance rates: A representative study in Italy

RATIONALE

Despite its importance to counter the COVID-19 pandemic, vaccination has raised hesitation in large segments of the population. This hesitation makes it important to understand the mechanisms underlying vaccine acceptance. To this end, the study adopts the Semiotic Cultural Psychology Theory, holding that social behaviors - and therefore, vaccination acceptance - depend on the cultural meanings in terms of which people interpret the social world.

OBJECTIVE

The study aims at estimating the impact a) of the way people interpret the socio-institutional context of the pandemic and b) of the underlying cultural worldviews on vaccine acceptance. More particularly, the study tested the three following hypotheses. a) The meanings grounding the interpretation of the socio-institutional framework - that is, trust in institutions and political values - are an antecedent of vaccination acceptance. b) The impact of these meanings is moderated by the cultural worldviews (operationalized as symbolic universes). And c), the magnitude of the symbolic universes' moderator effect depends on the uncertainty to which the respondent is exposed. The exposure to uncertainty was estimated in terms of socioeconomic status - the lower the status, the high the exposure to uncertainty.

METHODS

An Italian representative sample (N = 3020) completed a questionnaire, measuring vaccination acceptance, the meanings attributed to the socio-institutional context - that is, political values and trust in institutions - and symbolic universes.

RESULTS

The findings were consistent with the hypotheses. a) Structural equation modelling proved that vaccine acceptance was predicted by trust in institutions. b) Multigroup analysis revealed that symbolic universes moderated the correlation between trust in institutions and vaccine acceptance. And c), the moderation effect of symbolic universes proved to occur only in the segment of lower socio-economic status (i.e., the group exposed to higher uncertainty).

CONCLUSIONS

Vaccination acceptance is not only a medical issue; it is also dependent upon the rationalization of the socio-institutional context. Implications for the promotion of vaccination acceptance are discussed.

Understanding the psychological antecedents of COVID-19 vaccine acceptance among Black Americans: implications for vaccine communication

BACKGROUND

Guided by the 5C (confidence, complacency, constraints, calculation, and collective responsibility) model of vaccination behavior, we examine the psychological antecedents of COVID-19 vaccine acceptance (i.e. attitudes and intentions toward COVID-19 vaccination) among Black Americans, a group disproportionately affected by the coronavirus pandemic.

METHOD

We conducted a national survey of Black Americans (N = 1,497) in February/March 2021.

RESULTS

We found that, among the five psychological antecedents, three (confidence, calculation - or extensive information searching, and collective responsibility) significantly predicted attitudes toward COVID-19 vaccination and had indirect effects on vaccination intentions through vaccination attitudes. Two antecedents (confidence and collective responsibility) also directly predicted vaccination intentions. Our analysis suggests that a partially mediated model produced better fit than a fully mediated model.

CONCLUSIONS

Developing culturally tailored interventions for Black Americans that build confidence in COVID-19 vaccines, highlight collective responsibility, and attend to Black Americans' information sources is key to boosting Black Americans' COVID-19 vaccine acceptance. Future research is needed to understand how historical and ongoing racism affects the psychological antecedents of COVID-19 vaccine acceptance among Black Americans.

The intersection of gender and race in older adults' decision to receive COVID-19 vaccines

COVID-19 vaccines are essential public health tools for protecting older adults, who are at high risk of severe outcomes associated with COVID-19. Little is known, however, about how older adults approach the decision to receive a COVID-19 vaccine. We hypothesized that intersections between gender and race may provide unique insight into the decision-making process and the factors that lead to vaccine uptake among hesitant individuals. We performed in-depth interviews with 24 older adults who had been vaccinated against COVID-19 and used the framework approach with an intersectional lens to analyze data. Two typologies emerged: eager compliers did not question the need to vaccinate, whereas hesitant compliers were skeptical of the vaccine and underwent a thorough decision-making process prior to vaccination. For eager compliers, the vaccine offered protection from a disease that posed a serious threat, and few risks were perceived. In contrast, hesitant compliers perceived risks associated with the vaccine product or mistrusted the infrastructure that led to rapid vaccine development. Hesitancy was greater among Black participants, and only Black participants reported mistrust in vaccine infrastructure. At the intersection of gender and race, a 'White male effect' was observed, whereby White men perceived the fewest risks associated with the vaccine, and Black women were the most fearful of serious side effects. Nearly all hesitant compliers ultimately got vaccinated due to the threat of COVID-19. Convenient access through vaccine clinics in senior's buildings was pivotal for hesitant compliers and external and internal influences had differential impacts by race and gender. Emphasizing the risk of COVID-19, convenient and accessible opportunities for vaccination, and messages that are targeted to specific groups are likely to increase vaccine uptake among older adults.

Knowledge and willingness to receive a COVID-19 vaccine: a survey from Anhui Province, China

OBJECTIVES

Vaccinations can prevent COVID-19 and control its spread quickly and efficiently. This study aimed to investigate knowledge and willingness of geriatric care facility staff to receive a COVID-19 vaccine, and to provide a basis for the government to promote the COVID-19 vaccine and guide people to get vaccinated.

STUDY DESIGN

A cross-sectional study.

METHODS

Data on characteristics of the participants, knowledge about the COVID-19 vaccine, and willingness to get vaccinated for COVID-19 were collected through an online survey from May 19 to June 18, 2021. Statistical analyses were conducted with ANOVA, chi-square, logistic regression.

RESULTS

The survey illustrated that the highest score of COVID-19 vaccine knowledge was 50, the lowest 20, and the average 44.22. It also demonstrated that 91.3% of the participants had a good knowledge of COVID-19 vaccine, and that 97.3% participants were willing to receive the COVID-19 vaccine. The results showed that geriatric care facility staff had varied level of the COVID-19 vaccine knowledge depending upon their age, educational background, and other factors, and correspondingly, their willingness to receive COVID-19 vaccine was affected by their knowledge level of COVID-19 vaccine.

CONCLUSIONS

In general, the participants, the staff of geriatric care facilities in Anhui Province, had good mastery of the COVID-19 vaccine, and they were willing to get vaccinated. However, there still existed a few participants with poor knowledge, who were unwilling to get vaccinated against COVID-19. Government can guide people to accept vaccination by enhancing publicity about the effects and adverse reactions of COVID-19 vaccines.

How do COVID-19 vaccine mandates affect attitudes toward the vaccine and participation in mandate-affected activities? Evidence from the United States

The spread of COVID-19 has prompted many governments, schools, and companies to institute vaccine mandates. Proponents suggest that mandates will enhance public health and increase vaccination rates. Critics suggest that evidence of mandates' effectiveness is unclear and warn that mandates risk increasing societal inequalities if unvaccinated minority groups opt out of educational, commercial, and social activities where mandates are required. We conduct an original survey experiment on a nationally representative sample of 1,245 Americans to examine the efficacy and effect of COVID-19 mandates. Our findings suggest that mandates are unlikely to change vaccination behavior overall. Further, they may increase the likelihood that sizable percentages of the population opt out of activities where vaccines are mandated. We conclude that mandates that do go into effect should be accompanied by persuasive communications targeted to specific information needs and identities.

Exploring COVID-19 Vaccine Hesitancy Amongst Black Americans: Contributing Factors and Motivators

PURPOSE

To determine reasons for hesitancy towards COVID-19 vaccination and motivators to increase COVID-19 vaccine uptake among Black Americans.

DESIGN

Mixed-methods.

SETTING

Individual interviews in March-April 2021.

PARTICIPANTS

Black adults (20-79 years) who attended a church in Boston, MA and identified as "vaccine hesitant" (n = 18).

METHODS

Individual in-depth Zoom interviews to elicit participant views on vaccines in general, specific reasons for COVID-19 vaccine hesitancy, and trusted sources of information. Participants were also asked about possible motivators that could increase COVID-19 vaccine uptake. Transcripts were de-identified and analyzed for major themes using an inductive approach.

RESULTS

Analysis included 18 complete interviews. Lack of trust in the government, healthcare, or pharmaceutical companies (n = 18), rushed development (n = 14), fear of side effects (n = 12), history of medical mistreatment (n = 12), and a perception of low risk of disease (n = 9) were the top-cited reasons for COVID-19 vaccine hesitancy. Motivators likely to increase COVID-19 vaccine uptake included more data (n = 17), friends and family getting vaccinated (not celebrities) (n = 11), and increased opportunities that come along with being vaccinated (n = 8).

CONCLUSION

There were many reasons for COVID-19 vaccine hesitancy, as reported by participants who were all Black Americans in the Boston area. The public health challenge of increasing vaccine uptake in the Black community is nuanced and intervention efforts may be more successful if delivered by trusted members of the community and tailored to the needs of individuals.

Parental refusal and hesitancy of vaccinating children against COVID-19: Findings from a nationally representative sample of parents in the U.S

The uptake rate of COVID-19 vaccines among children remains low in the U.S. This study aims to 1) identify sociodemographic and behavioral factors influencing parental refusal of vaccinating children, and 2) quantify the relative importance of vaccine characteristics in parental hesitancy of vaccinating children. An online survey was conducted from October to November 2021 among a probability-based, representative sample of 1456 parents with children under age 18. The survey included a discrete choice experiment asking parents to choose between two hypothetical COVID-19 vaccine alternatives with varying levels of characteristics in 10 hypothetical scenarios. Logistic regressions were used to estimate parental refusal (refused to choose any vaccine alternatives in all hypothetical scenarios) and random parameter logit regressions were used to estimate parental hesitancy (choice of vaccine alternatives depended on vaccine characteristics) of vaccinating children. About 20% parents refused to vaccinate children. The refusal is predicted by parents' sociodemographic characteristics, political orientation, vaccination status, and parents' and children's previous exposure with COVID-19. Among parents who were willing to consider vaccinating children, the most important vaccine characteristics are risk of severe side effects (31.2% relative importance) and effectiveness (30.7%), followed by protection duration (22.6%), local coverage (9.4%), and hospitalization rate of unvaccinated children (6.1%). Our findings imply that policymakers and public health professionals could develop outreach programs at community level to encourage specific subgroups and focus on vaccination depoliticization. Effectively communicating the low risk of severe side effects and high effectiveness of the vaccines may relieve some of the parental hesitancy.

Cross-sectional assessment of predictors for COVID-19 vaccine uptake: an online survey in Greece

Objective

To estimate the percentage of the general population vaccinated against the COVID-19 and to investigate the factors associated with COVID-19 vaccine uptake.

Material and methods

We conducted an online cross-sectional study in Greece during August 2021. We included individuals over 18 years of age. Independent variables included socio-demographic data of the participants and attitudes towards COVID-19 vaccination and pandemic. Our outcome variable was COVID-19 vaccination status, measured through "yes/no" answers.

Results

Most participants had been vaccinated against the COVID-19 (87.8%). Multivariate analysis identified that increased age and a higher level of education were associated with an increased likelihood of COVID-19 vaccination. Also, participants working in health services, participants without a previous COVID-19 diagnóstico, and those with previous seasonal influenza vaccination history had a greater probability to take a COVID-19 vaccine. Additionally, increased self-perceived severity of COVID-19, knowledge regarding COVID-19, and trust in COVID-19 vaccines and scientists were associated with COVID-19 vaccine uptake. On the other hand, the likelihood of vaccination was lower for participants who were more concerned about the side effects of COVID-19 vaccination.

Conclusions

Understanding the factors affecting individuals' decision to take a COVID-19 vaccine is essential to improve the COVID-19 vaccination coverage rate. Policymakers and scientists should scale up their efforts to increase the COVID-19 vaccination rate among specific population groups such as young people, people with a low level of education, etc.

Vaccine nationalism among the public: A cross-country experimental evidence of own-country bias towards COVID-19 vaccination

What types of vaccines are citizens most likely to accept? We argue that citizens' identification with their nation may lead them to prefer vaccines developed and produced within their national borders, to the exclusion and/or detriment of vaccines from other nations. We administered a conjoint experiment requesting 15,000 adult citizens across 14 individual countries from around the world to assess 450,000 profiles of vaccines that randomly varied on seven attributes. Beyond vaccine fundamentals such as efficacy rate, number of doses, and duration of the protection, we find that citizens systematically favor vaccines developed and produced in their own country of residence. The extent of preference in favor of vaccines developed and produced within the national borders is particularly large among citizens who identify more strongly with their nation, suggesting nationalism plays a role in explaining the bias in favor of vaccines developed and produced locally. This public opinion bias on vaccine preferences has significant theoretical and practical implications.

Propolis efficacy on SARS-COV viruses: a review on antimicrobial activities and molecular simulations

This current study review provides a brief review of a natural bee product known as propolis and its relevance toward combating SARS-CoV viruses. Propolis has been utilized in medicinal products for centuries due to its excellent biological properties. These include anti-oxidant, immunomodulatory, anti-inflammatory, anti-viral, anti-fungal, and bactericidal activities. Furthermore, studies on molecular simulations show that flavonoids in propolis may reduce viral replication. While further research is needed to validate this theory, it has been observed that COVID-19 patients receiving propolis show earlier viral clearance, enhanced symptom recovery, quicker discharge from hospitals, and a reduced mortality rate relative to other patients. As a result, it appears that propolis could probably be useful in the treatment of SARS-CoV-2-infected patients. Therefore, this review sought to explore the natural properties of propolis and further evaluated past studies that investigated propolis as an alternative product for the treatment of COVID-19 symptoms. In addition, the review also highlights the possible mode of propolis action as well as molecular simulations of propolis compounds that may interact with the SARS-CoV-2 virus. The activity of propolis compounds in decreasing the impact of COVID-19-related comorbidities, the possible roles of such compounds as COVID-19 vaccine adjuvants, and the use of nutraceuticals in COVID-19 treatment, instead of pharmaceuticals, has also been discussed.

Attitude and Acceptance of COVID-19 Vaccine in Parents and Adolescents: A Nationwide Survey

PURPOSE

Coronavirus disease 2019 (COVID-19) vaccines are currently authorized for emergency use in adolescents aged 12-17 years; however, there is concern and uncertainty regarding the safety and necessity of COVID-19 vaccination. A survey was carried out to assess the attitudes and acceptance towards vaccination in adolescents.

METHODS

A nationwide web-based survey was conducted among adolescents aged 12-17 years and their parents between June 29 and July 8, 2021 on a platform provided by the Ministry of Education.

RESULTS

A total of 341,326 parents and 272,914 adolescents participated in this study. Intention for vaccination was 69.1% for adolescents, and 72.2% of parents reported they would recommend vaccination for their child. Among adolescents, perception of safety (odds ratio [OR] 4.09, 95% confidence interval [CI] 3.95-4.22), effectiveness (OR 2.24, 95% CI 2.17-2.32), and risk-benefit (OR 1.75, 95% CI 1.72-1.78) had the highest impact on intention for vaccination. Also, perceived risk (OR 1.14, 95% CI 1.12-1.17), severity (OR 1.12, 95% CI 1.10-1.13) for COVID-19 infection, self-health perception (OR 1.12, 95%, CI 1.10-1.14) and recent vaccination of childhood vaccines (OR 1.25, 95% CI 1.19-1.32) were related to intention for COVID-19 vaccination. On the other hand, self-perceived knowledge (OR 0.96, 95% 0.95-0.98) was related to vaccine hesitancy. Gender or school district did not influence intention for COVID-19 vaccination in adolescents.

DISCUSSION

Decisions on COVID-19 vaccination for adolescents should be a shared process between adolescents, parents, and physicians based on updated information on safety and effectiveness.

Young adult preference analysis on the attributes of COVID-19 vaccine in the Philippines: A conjoint analysis approach

Objective

Vaccines are utilized to prevent the severity of illnesses like the COVID-19 virus. Currently, there are a lot of COVID-19 vaccines available in the market like Pfizer, Moderna, AstraZeneca, Johnson and Johnson, and Sinovac. This research aimed to analyze the preference on the existing vaccine attributes of COVID-19.

Study design

Specifically, this study considered 7 attributes such as cost, brand, recommendations, efficacy, side effects, vaccine type, and dose.

Methods

A conjoint analysis with orthogonal design was utilized and 865 respondents were participated.

Results

The result showed that consumers considered brand as the highest attribute, specifically Pfizer and Moderna among other brands. Moreover, the efficacy of 90% and higher were the preferred vaccine with 1 in 100 patient side effects reported. It was seen that safety and effectiveness is the priority in choosing a COVID-19 vaccine. Interestingly, the knowledge and understanding of the COVID-19 vaccine was found to drive consumer's preference for the vaccines available.

Conclusions

The findings of this study could be utilized by the government to increase the willingness to be vaccinated. Lastly, the result of this study would pave a way to promote herd immunity to help fight the COVID-19 pandemic worldwide.

Coronavirus vaccine hesitancy among unvaccinated Austrians: Assessing underlying motivations and the effectiveness of interventions based on a cross-sectional survey with two embedded conjoint experiments

Background

To date, Austria is among the countries with the lowest coronavirus vaccination rates in Western Europe. It has announced the introduction of a general vaccine mandate but is experiencing an increasing societal polarization over this issue. We, therefore, aimed to provide evidence on the underlying motivations of vaccine hesitancy and evaluate what kinds of interventions - information, incentives, and rules - might increase vaccination readiness.

Method

We conducted a cross-sectional survey with a sample of 1,543 unvaccinated Austrian residents in October 2021, including two embedded conjoint experiments.

Findings

We screened 8,190 individuals to recruit the sample matching the Austrian micro-census. In experiment 1, easing rather than tightening of societal restrictions, a fixed monetary reward compared to a lottery and physicians' recommendations were associated with significantly higher intentions to get vaccinated. In experiment 2, standard approval by European or national authorities and simple information had a significant positive effect on vaccination propensity. Among the unvaccinated, fear of side effects, beliefs that comorbidities or the desire to have children would not allow vaccination, the assumption that the own immune system would provide sufficient protection, conspirational thinking (e.g., the refusal to participate in a 'large genetic experiment'), low trust in societal institutions, and spiritual beliefs were very common.

Interpretation

While many unvaccinated showed a low propensity to become vaccinated, we identified a cluster of 195 (23% of the participants without missing values) that could potentially be reached by information and incentives, including people with heightened comorbidity rates or a desire for children.

Funding

Vienna Science and Technology Fund.

Factors Associated with COVID-19 Vaccine Acceptance in Morocco: Applying the Health Belief Model

To identify factors that influenced Moroccans’ intention to get a COVID-19 vaccine, a cross-sectional survey among a Moroccan sample was conducted based on Health Belief Model constructs. Participants’ sociodemographic characteristics, perceived susceptibility, perceived severity, perceived barriers, perceived benefits, self-efficacy, cues to action, and intention to receive vaccine data were collected and analyzed using a structural equation model (SEM). The survey was completed by 3800 individuals; 57.2% were men, 44.5% were aged 30 to 44, and 44.6% were married. After controlling for confounders, being a woman and having a chronic disease were associated with higher acceptance of the COVID-19 vaccine. The strongest predictor for the intention of receiving a vaccine was participants who were married. Most of the HBM constructs were shown to be significantly associated with vaccine acceptance. Susceptibility and Benefits were the strongest predictors of acceptance of the COVID-19 vaccine (standardized path coefficient, SPC = 0.23), followed by Severity (SPC = 0.22). Conversely, given the negative correlation between barriers and intention (SPC = −0.08), it is necessary to maintain a high level of transparency regarding the vaccines’ safety. Our study provides guidance for an implementation of vaccination strategies, intending to bolster the overall COVID-19 immunization program.

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.

Understanding the influence of political orientation, social network, and economic recovery on COVID-19 vaccine uptake among Americans

The COVID-19 pandemic poses unprecedented risks to the well-being of Americans. To control the pandemic, a sufficient proportion of the population needs to be vaccinated promptly. Despite the proven efficacy and widespread availability, vaccine distribution and administration rates remain low. Thus, it is important to understand the public behavior of COVID-19 vaccination. This study aims to identify determinants at multiple levels that promote or inhibit one's vaccine uptake. We combine individual-level data from a national survey conducted in the summer of 2021 with corresponding state-level indicators. Findings of multilevel logistic regression show that political orientation, social network, and economic recovery altogether have significant influence. We articulate that individual decision to take the vaccine are a function of their personal characteristics and are also rooted in their home state's political, public health, and economic contexts. These findings contribute to the literature and have policy implications. Knowledge of the profiles among people who take/refuse the vaccine provides essential information to leverage certain factors and maximize vaccine uptake to mitigate the pandemic's devastating impact.

People’s perceptions of, willingness-to-take preventive remedies and their willingness-to-vaccinate during times of heightened health threats

Pandemics, such as the current SARS-CoV-2 pandemic, represents a health threat to humans worldwide. During times of heightened health risks, the public’s perceptions, and acceptance of evidence-based preventive measures, such as vaccines, is of high relevance. Moreover, people might seek other preventive remedies to protect themselves from getting infected (e.g., herbal remedies, nutritional supplements). A recent study on consumers’ preference for naturalness showed that people put more weight on perceived naturalness of a preventive remedy compared to a curative one. This result was attributed to the increased focus on perceived effectiveness as opposed to perceived risk. This raises the question whether the current pandemic would shift people’s perceptions from prevention to curing and thus, exhibit a preference for synthetic remedies because they are seen as more effective. The present online experiment (conducted in April 2021) investigated people’s perceptions of vaccines and remedies within the context of the current SARS-CoV-2 pandemic. A 2x2 between-subject design with type of remedy (natural vs. synthetic) and salience of SARS-CoV-2 pandemic (high vs. low) was conducted in Switzerland in spring 2021 (N = 452). The data did not provide evidence of a curative mindset for preventive remedies, as the participants exhibited a clear preference for the natural remedy compared to the synthetic remedy. Our study stresses the importance of understanding people’s mindsets on how to protect themselves from infection with a virus during an ongoing pandemic to tackle misinformation and vaccine hesitancy.

Public preferences and willingness to accept a hypothetical vaccine to prevent a pandemic in Japan: a conjoint analysis

OBJECTIVES

Understanding public vaccine acceptability is critical to preparing for future pandemics. This research investigated Japanese individuals' willingness to be vaccinated against a hypothetical infectious disease.

METHODS

A conjoint analysis was conducted with a general public panel via an Internet survey agency. Vaccine efficacy, vaccine safety, duration of immunity, and price were chosen as analysis attributes. Each respondent chose from 12 hypothetical scenarios using an online panel.

RESULTS

From the 2,155 complete responses, 51,720 results were extracted and analyzed. Higher efficacy, lifetime immunity duration, and fear of the pandemic positively affected willingness to be vaccinated, while higher vaccination price and higher toxicity had negative effects. The number of infected individuals and deaths had no significant impact. A total of 69.2% of the study population reported being willing to receive a vaccine with 100% efficacy, lifetime immunity, and low toxicity and free of charge.

CONCLUSIONS

This study assessed the preferences for vaccines against infectious diseases with the potential to become pandemics during the COVID-19 pandemic in Japan. This result can influence vaccine-related policy and pandemic preparedness and help governments consider public intention to prepare health communication campaigns that encourage vaccination.

Perceived facilitators and barriers to intentions of receiving the COVID-19 vaccines among elderly Chinese adults

Elderly adults hold different beliefs regarding vaccination and are at higher risks for COVID-19 related illnesses and deaths. The current study aims to explore elderly (aged 65 or above) Chinese adults’ intentions to get vaccinated against COVID-19 and the facilitators and barriers to vaccination intentions. We conducted in-depth interviews with 35 elderly adults in China through the lens of the integrative model of behavioral prediction. The results identified a number of facilitators, including convenience (both individual and collective), psychological and physiological wellbeing, collective wellbeing, supportive normative referents, and trust in the government, and some barriers, including vaccine ineffectiveness, side effects, safety, unsupportive normative referents, and the accessibility, affordability, and availability of COVID-19 vaccines. In addition, the results revealed participants’ decision-making process: collective wellbeing and trust in the government overrode perceived barriers and perceived individual-level risks, which eventually overwhelmingly led to a high level of intentions to get vaccinated. Practical implications related to vaccine promotion and trust in the government were discussed.

Factors Associated with COVID-19 Vaccine Hesitancy among Visible Minority Groups from a Global Context: A Scoping Review

Vaccine hesitancy is one of the top ten greatest threats to global health. During the COVID-19 era, vaccine hesitancy poses substantial risks, especially in visible minorities, who are disproportionately affected by the pandemic. Although evidence of vaccine hesitancy exists, there is minimal focus on visible minorities and the reasons for hesitancy in this group are unclear. Identifying these populations and their reasons for vaccine hesitancy is crucial in improving vaccine uptake and curbing the spread of COVID-19. This scoping review follows a modified version of the Arksey and O'Malley strategy. Using comprehensive search strategies, advanced searches were conducted on Medline, CINAHL, and PubMed databases to acquire relevant articles. Full-text reviews using inclusion and exclusion criteria were performed to extract themes of vaccine hesitancy. Themes were grouped into factors using thematic qualitative analysis and were objectively confirmed by principal component analysis (PCA). To complement both analyses, a word cloud of titles and abstracts for the final articles was generated. This study included 71 articles. Themes were grouped into 8 factors and the top 3 recurring factors were safety and effectiveness of the vaccine, mistrust, and socioeconomic characteristics. Shedding light on these factors could help mitigate health inequities and increase overall vaccine uptake worldwide through interventions and policies targeted at these factors. Ultimately, this would help achieve global herd immunity.

Frames that matter: Increasing the willingness to get the Covid-19 vaccines

Herd immunity against Covid-19 demands a high rate of vaccination, which may be challenging to meet given vaccine hesitancy in the U.S. How can Americans' willingness to get vaccinated be increased? Using a survey experiment, we apply seven framing treatments to a representative sample of 1642 U.S. residents that test ways to increase willingness: expert and political figure endorsements, demonstrations of receiving the vaccine, information about the vaccine's approval process, and information underscoring the pandemic's devastating economic impact. We find the approval process and the economy treatments increase the odds of higher vaccination willingness by 42% (p = 0.068) and 46% (p = 0.060), respectively. Additionally, we find suggestive evidence that the effectiveness of a message depends on whether a respondent finds the message/messenger credible. The study advances the understanding of vaccine hesitancy by demonstrating effective public health messaging strategy can facilitate greater acceptance of vaccination.

COVID-19 Vaccine Hesitancy among Italian University Students: A Cross-Sectional Survey during the First Months of the Vaccination Campaign

Achieving high levels of vaccination coverage against COVID-19 may be hindered by vaccine hesitancy. We quantified over time the prevalence of COVID-19 vaccine hesitancy among university students, investigated its determinants, and analyzed student attitudes, risk perceptions and compliance with preventive measures. The survey was administered online from 1 March to 30 June 2021. A multivariable logistic regression model was built to identify predictors of hesitancy. Overall, we collected 5369 questionnaires that were grouped into three survey periods (March, April-May, and May-June). The response rate ranged from 81.2% to 76.4%, whereas vaccine hesitancy ranged from 22% to 29%. Multivariable analysis showed that April-May participants had higher odds of hesitancy than March respondents. Other positive predictors were being male, not being a healthcare student, having a lower academic level, and not disclosing a political position. Conversely, higher levels of perceived COVID-19 severity, concern for the emergency, confidence in vaccine safety and effectiveness, and self-reported adherence to mask wearing indoors and outdoors were negatively associated with hesitancy. We found that vaccine hesitancy changed over time and in relation to several factors. Strategies aimed at increasing the students' awareness and engagement, restoring confidence in health authorities, and limiting disinformation around the vaccines should be devised.

Trends in COVID-19 vaccination intent from pre- to post-COVID-19 vaccine distribution and their associations with the 5C psychological antecedents of vaccination by sex and age in Japan

Vaccine hesitancy regarding the coronavirus disease 2019 (COVID-19) vaccine is widespread during the COVID-19 pandemic. Many recent studies have reported that the confidence of the vaccination and perceived risk were associated with vaccination intent, yet few studies have focused on other psychological factors. This study aimed to clarify the trends in COVID-19 vaccination intent and to identify the association between the 5C psychological antecedents and COVID-19 vaccination intent by sex and age in Japan. This was a longitudinal study conducted through an Internet-based survey from January 2021 to April 2021 before and after vaccine distribution in Japan, including 2,655 participants recruited by quota sampling. Participants were asked to indicate how likely they were to get vaccinated against COVID-19. In the second survey, the participants responded to questions regarding the 5C psychological antecedents: confidence, complacency, constraints (structural and psychological barriers), calculation (engagement in extensive information searching), and collective responsibility (willingness to protect others). Multiple logistic regression analysis was performed to clarify the association between the 5C psychological antecedents and COVID-19 vaccination intent in the second wave survey. COVID-19 vaccination intent improved from 62.1% to 72.4% after vaccine distribution, but no significant difference was found in young men. Confidence and collective responsibility were positively associated with vaccination intent, and calculation was negatively associated among all generations. COVID-19 vaccination intent may be affected not only by confidence and constraints but also by calculation and collective responsibility, and further research is needed.

Quantifying healthcare and welfare sector workers' preferences around COVID-19 vaccination: a cross-sectional, single-profile discrete-choice experiment in France

OBJECTIVES

To analyse preferences around promotion of COVID-19 vaccination among workers in the healthcare and welfare sector in Fance at the start of the vaccination campaign.

DESIGN

Single-profile discrete-choice experiment. Respondents in three random blocks chose between accepting or rejecting eight hypothetical COVID-19 vaccination scenarios.

SETTING

4346 healthcare and welfare sector workers in France, recruited through nation-wide snowball sampling, December 2020 to January 2021.

OUTCOME

The primary outcomes were the effects of attributes' levels on hypothetical acceptance, expressed as ORs relative to the reference level. The secondary outcome was vaccine eagerness as certainty of decision, ranging from -10 to +10.

RESULTS

Among all participants, 61.1% made uniform decisions, including 17.2% always refusing vaccination across all scenarios (serial non-demanders). Among 1691 respondents making variable decisions, a strong negative impact on acceptance was observed with 50% vaccine efficacy (compared with 90% efficacy: OR 0.05, 95% CI 0.04 to 0.06) and the mention of a positive benefit-risk balance (compared with absence of severe and frequent side effects: OR 0.40, 0.34 to 0.46). The highest positive impact was the prospect of safely meeting older people and contributing to epidemic control (compared with no indirect protection: OR 4.10, 3.49 to 4.82 and 2.87, 2.34 to 3.50, respectively). Predicted acceptance was 93.8% for optimised communication on messenger RNA vaccines and 16.0% for vector-based vaccines recommended to ≥55-year-old persons. Vaccine eagerness among serial non-demanders slightly but significantly increased with the prospect of safely meeting older people and epidemic control and reduced with lower vaccine efficacy.

DISCUSSION

Vaccine promotion towards healthcare and welfare sector workers who hesitate or refuse vaccination should avoid the notion of benefit-risk balance, while collective benefit communication with personal utility can lever acceptance. Vaccines with limited efficacy will unlikely achieve high uptake.

Assessing influenza vaccination success to inform COVID-19 vaccination campaign

Given recent downward trends in daily rates of COVID‐19 vaccinations, it is important to reassess strategies to reach those most vulnerable. The success and efficacy of vaccination campaigns for other respiratory illnesses, such as influenza, may help inform messaging around COVID‐19 vaccinations. This cross‐sectional study examines the individual‐level factors associated with, and the spatial distribution of, predictors of COVID‐19 severity, and uptake of influenza and hepatitis B (as a negative control) vaccines across NYC. Data were obtained from the 2018 Community Health Survey (CHS), including self‐reported influenza and hepatitis B vaccine uptake, diabetes, asthma, hypertension, body mass index (BMI), age, race/ethnicity, educational attainment, borough, and United Hospital Fund (UHF) neighborhood of residence. A CDC‐defined COVID‐19 severity risk score was created with variables available in the CHS, including diabetes, asthma, hypertension, BMI ≥ 30 kg/m², and age ≥65 years old. After adjustment, there was a significant positive association between COVID‐19 severity risk score and influenza vaccine uptake (1: OR_adj = 1.49, 95% CI 1.28–1.73; 2: OR_adj = 1.99; 95% CI: 1.65–2.41; 3+: OR_adj = 2.89; 95% CI: 2.32–3.60, compared to 0). Hepatitis B vaccine uptake was significantly inversely associated with COVID‐19 severity risk score (1: OR_adj = 0.67; 95% CI: 0.57–0.79; 2: OR_adj = 0.54; 95% CI: 0.44–0.66; 3+: OR_adj = 0.45; 95% CI: 0.36–0.56, compared to 0). The influenza vaccination campaign template is effective at reaching those most at risk for serious COVID‐19 and, if implemented, may help reach the most vulnerable that have not yet been vaccinated against COVID‐19.

Determinants of COVID-19 vaccine preference: A survey study in Japan

Objective

Vaccination is a critical measure for containing the COVID-19 pandemic. We survey the determinants that affect the preference for COVID-19 vaccines in Japan, a vaccine hesitant nation.

Setting and design

We conducted a randomized conjoint analysis survey of the preference for vaccines on the Internet by recruiting a nonprobability sample of 15,000 Japanese adults. The survey assigned 5 choice tasks to the respondents. In each task, the respondents evaluated 2 hypothetical COVID-19 vaccines and were asked which they would choose. The vaccine attributes included efficacy, major and minor adverse side effects, country of vaccine development and clinical trial, and vaccine type.

Treatment

The choice task asked the participants to select a vaccine from 2 hypothetical vaccines as an optional vaccine or select a vaccine as mandated one with a probability of 0.5 for each.

Results

Compared to China-developed vaccines, domestically developed or US-developed vaccines raised the choice probability by 37.3 and 27.4 percentage points, respectively. A domestic clinical trial increased the choice probability by 14.8, an increase in efficacy from 50% to 90% increased that by 18.0, and a decrease in the risk of severe adverse side effects from 1 per 10 thousand to 1 per 1 million increased that by 16.9 percentage points, respectively. The vaccine type was irrelevant. Making vaccination compulsory increased the choice probability of China- and Russia-developed vaccines by 0.6 and 0.4, high-risk vaccines by 0.5, and a modestly effective (70%) vaccine by 0.4 percentage points, respectively. General vaccination hesitancy, political positions, demographic characteristics, education, and income were irrelevant.

Conclusions

A domestically developed vaccine with a domestic clinical trial could substantially increase the preference for the vaccine. Making vaccination compulsory could modestly reduce the penalty for a vaccine with adverse side effects, geopolitical, and efficacy concerns, possibly through mitigating free-riding concerns to achieve herd immunity.

•

We implement a randomized conjoint experiment on preference of COVID-19 vaccines.

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We asked 15,000 Japanese adults which to prefer between two hypothetical vaccines.

•

As a treatment, we randomly assigned voluntary and compulsory vaccination scenarios.

•

Domestic development and clinical trial were substantially preferred.

•

Compulsory vaccination modestly raised preference for riskier vaccines.

Factors Affecting Hesitancy to mRNA and Viral Vector COVID-19 Vaccines among College Students in Italy

Vaccine hesitancy (VH) may be significant in jeopardizing efforts to mass containment of COVID-19. A cross-sectional survey was carried out on a sample of 2667 Italian college students, before the COVID-19 vaccines became available for this age group (from 7 May to 31 May 2021). An online survey was created to obtain information about socio-demographic, health-related, and psychological factors linked to mRNA and viral vector COVID-19 vaccines. Statistically significant higher VH (30.4%) and vaccine resistance (12.2%) rates were found for viral vector than mRNA COVID-19 vaccines (7.2% and 1.0%, respectively; p < 0.001). Factors related to viral vector VH were partially different from those related to mRNA VH. Students with greater endorsement on conspiracy statements and negative attitudes toward the vaccine had higher odds of being vaccine-hesitant or -resistant. Students who had received a previous COVID-19 test and who scored higher on the agreeableness personality dimension had lower odds to be vaccine-hesitant or -resistant. The willingness to choose the vaccine was related to the viral vector but not to the mRNA VH. Taking into consideration the factors involved in vaccine hesitancy/resistance in college students could represent a key public health strategy to increase vaccine coverage and reduce viral spreading.

Young Adults' Intentions and Rationales for COVID-19 Vaccination Participation: Evidence from a Student Survey in Ho Chi Minh City, Vietnam

The COVID-19 pandemic, a source of fear and anxiety worldwide, has caused many adverse impacts. Collaborative efforts to end COVID-19 have included extensive research on vaccines. Many vaccination campaigns have been launched in many countries, including Vietnam, to create community immunization. However, citizens' willingness to participate is a prerequisite for effective vaccination programs and other related policies. Among all demographic groups, participation rates among young adults are of interest because they are an important workforce and are a source of high infection risk in the community. In March 2021, a pool of approximately 6000 participants in Ho Chi Minh City were randomly polled using an email-based online survey. The exploratory results of 398 valid observations show that students' perceptions of the dangers of COVID-19 and the importance of vaccination were both relatively high (4.62/5 and 4.74/5, respectively). Furthermore, 83.41 percent of students polled (n = 332) chose vaccination, while 16.59 percent chose hesitation (n = 64) and not to be vaccinated (n = 2). More importantly, our estimated results of the Bayesian regression model (BRM) show that the perceived importance of the vaccine, concerns about the vaccine's side effects, and a lack of access to information are the top three reasons for their reluctance and/or refusal to get vaccinated. These findings are a valuable resource for politicians, researchers, and those interested in COVID-19 vaccinations to devise and execute campaigns to effectively combat this terrifying pandemic.