Can a COVID-19 vaccine live up to Americans' expectations? A conjoint analysis of how vaccine characteristics influence vaccination intentions

Factors influencing individual vaccine preferences for COVID-19 in the Sunyani Municipality, Ghana: An observational study using discrete choice experiment analysis

Background and Aims

There has been hesitancy among people with regard to accepting vaccines, especially that of coronavirus disease-2019 (COVID-19). This hesitancy is aggravated by the different vaccine alternatives available and what one considers before choosing a particular vaccine. The aim of this article was to investigate some driving factors that can influence an individual's COVID-19 vaccine preference in the presence of other alternatives, using some specific vaccine characteristics.

Methods

Discrete choice questionnaire was designed using the attributes and their corresponding levels to collect data on participants' preference for a COVID vaccine over a period of 12 Weeks in Sunyani, Ghana, with the help of an observational study design. A total of 150 participants receiving Covid-19 vaccines at the University of Energy and Natural Resources Hospital were systematically selected and interviewed. Factors considered included: Efficacy of the vaccine, credibility of the manufacturing company, side effects of the vaccine, and availability of the vaccine. Data was analyzed using the conditional probit of the discrete choice experiment (DCE).

Results

Results from the study using the conditional probit of the discrete choice experiment (DCE) showed efficacy, side effects, and availability as significant attributes for preference. However, there was no preference with respect to the credibility of the manufacturing company. In addition, vaccine availability was not a dis-utility in comparison to the alternatives that are readily available. This disutility was however higher among males than females.

Conclusion

From the study, most respondents preferred a COVID-19 vaccine that is highly efficacious or a vaccine with milder side effect or a vaccine that may not necessarily be readily available. It was also observed that dis-utility is higher among males when it comes to vaccine not being readily available than females as the odds of a female choosing a vaccine that is readily available is much higher compared to their males counterparts.

Which factors drive the choice of the French-speaking Quebec population towards a COVID-19 vaccination programme: A discrete-choice experiment

OBJECTIVES

The aims of this study were to elicit preferences about the coronavirus disease 2019 (COVID-19) vaccine campaign in the general French-speaking adult Quebec population and to highlight the characteristics of the vaccine campaign that were of major importance.

METHODS

A discrete-choice experiment (DCE) was conducted between April and June 2021, in Quebec, Canada. A quota sampling method by age, gender and educational level was used to achieve a representative sample of the French-speaking adult population. The choice-based exercise was described by seven attributes within a vaccine campaign scenario. A mixed logit (MXL) model and a latent class logit (LCL) model were used to derive utility values. Age, gender, educational level, income and fear of COVID-19 were included as independent variables in the LCL.

RESULTS

A total of 1883 respondents were included for analysis, yielding 22,586 choices. From these choices, 3425 (15.16%) were refusals. In addition, 1159 (61.55%) individuals always accepted any of the vaccination campaigns, while 92 individuals (4.89%) always refused vaccine alternatives. According to the MXL, relative weight importance of attributes was effectiveness (32.50%), risk of side effects (24.76%), level of scientific evidence (22.51%), number of shots (15.73%), priority population (3.60%), type of vaccine (0.61%), and vaccination location (0.28%). Four classes were derived from the LCL model and attributes were more or less important according to them. Class 1 (19.8%) was more concerned about the effectiveness (27.99%), safety (24.22%) and the number of shots (21.82%), class 2 (55.3%) wanted a highly effective vaccine (40.16%) and class 3 (17.6%) gave high value to the scientific evidence (42.00%). Class 4 preferences (7.4%) were more balanced, with each attribute having a relative weight ranging from 1.84% (type of vaccine) to 21.32% (risk of side effects). Membership posterior probabilities to latent classes were found to be predicted by individual factors such as gender, annual income or fear of COVID-19.

CONCLUSIONS

Vaccination acceptance relies on multiple factors. This study allowed assessment of vaccination-specific issues through a choice-based exercise and description of factors influencing this choice by segmenting the sample and drawing profiles of individuals. Moreover, besides effectiveness and safety, a major point of this study was to show the importance given by the general population to the level of scientific evidence surrounding vaccines.

PATIENT OR PUBLIC CONTRIBUTION

A small group of citizens was involved in the conception, design and interpretation of data. Participants of the DCE were all from the general population.

Economic evaluation of vaccination against COVID-19: A systematic review

Background and Aims

Coronavirus has burdened considerable expenditures on the different health systems. Vaccination programs, the critical solution against pandemic diseases, are known as safe and effective interventions to prevent and control epidemics. We aimed to perform a systematic review to provide economic evidence of the value of different types of vaccines available to combat the Covid-19 to all health policymakers worldwide.

Methods

Electronic searches conducted on Medline/PubMed, Cochrane Library, Web of Science, Scopus, Embase, and other economic evaluation databases. Related and published articles searched up to March 2022 by using keywords such as "Vaccination," "Covid-19," "Cost-benefit," "Cost-utility," "Cost-effectiveness," "Economic Assessment," and "Economic evaluation." Followed by choosing the most suitable articles according to inclusion and exclusion criteria, data captured and the results extracted. The quality assessment of the articles performed by the checklist of CHEERS 2022. Finally, 13 articles included in the review.

Results

All messenger RNA vaccines were dominant with approximately 70% coverage against no vaccination in the primary vaccination program except in one study that looked at booster effects. From a payer's perspective, a dollar invested in a vaccine would be less profitable than from a societal perspective. Therefore, primary mass vaccination can be considered a cost-effective intervention in primary vaccination to save more lives and produce more positive externalities. However, the cost-benefit ratio for all vaccines increases when statistical lifetime value and global economic and educational disadvantages are considered.

Conclusion

The COVID-19 primary vaccination programs in regional outbreaks, from a long-term perspective, will demonstrate substantial cost-effectiveness. It is suggested that due to the positive externalities of vaccination, primary mass vaccination, with the help of COVAX-19TM, could be considered a reliable way to combat viral epidemics compared to the loss of individual lives and economic and educational disturbances around the world.

Preferences of COVID-19 Vaccines in the General Population in Belgrade, Serbia: A Qualitative Study

Few countries provided multiple COVID-19 vaccines for their citizens right from the start of mass immunization. In Serbia, four vaccines were available. Circumstances in which people had several options to choose from are unique. The purpose of this study was to identify motivators behind COVID-19 vaccination and the choice of COVID-19 vaccine among people who were immunized against COVID-19. Qualitative interviews with 35 vaccinated people aged > 18 years were conducted in May 2021 at the Institute of Public Health of Serbia, a reference institution for vaccination. Interviews were audio-recorded, transcribed and data were analyzed using qualitative content analysis. Four topics emerged: 1) Decision to receive COVID-19 vaccine; 2) Sources of information about the vaccine; 3) Choice of the COVID-19 vaccine and 4) Anti-vaccination sentiment around the vaccinated people. Participants were classified in two groups: those who were determined to receive the vaccine and those who were hesitant. People who were hesitant decided to receive the vaccine after reviewing the information collected from various sources, especially physicians. Although some participants accepted any vaccine regardless of their characteristics, there were others who had explicit preferences. These preferences stemmed mainly from their beliefs about particular vaccine's efficacy and safety, COVID-19 status (previous infection), living or lifestyle circumstances (residence or travel abroad), doctor's recommendation (underlying health status) or trust in expertise of that particular manufacturer's country of origin. Opting for appropriate vaccine was motivated by reasons specific to various individuals, which enabled them to make choices in line with their preferences and values.

What drives the vaccination intention against COVID-19? Application of EPPM, TAM, and theories of risk assessment

Vaccines are widely used to fight against COVID-19. However, COVID-19 vaccine hesitancy appears as some individuals are concerned with COVID-19 vaccines. This study investigates the vaccination intention against COVID-19 in China with the Extended Parallel Process Model (EPPM), Technology Acceptance Model (TAM), and theories of risk information assessment. Results showed that the formation mechanism of vaccination intention could be considered a psychological process, as subjective knowledge was a primary influence on correspondents' weighting of both the potentially positive (usefulness) and negative effects (threat) of vaccination. This unequal consideration then resulted in different levels of fear arousal between subjects. Driven by usefulness/threat perception and fear, people conducted different decision strategies, so-called analytical assessment, and experiential assessment to make vaccination decision. In addition to the direct effects of experiential assessment on vaccination intention, two decision strategies and fear arousal also affected people's vaccination intention through the mediation role of vaccination attitude. For policymakers and stakeholders, this study provides a knowledge base for confidence-building, and emotional guidance concerning against COVID-19 vaccination.

COVID-19 vaccination preferences during a pause in Johnson & Johnson vaccine administration

In April 2021, the US paused Janssen (J&J) COVID-19 vaccination because of reported blood clots post vaccination. This paper explores how vaccine decision-making--receiving a J&J vaccine right away vs waiting for a Pfizer vaccine--changed during the pause. In an opt-in internet-based survey April 2021 with 915 participants, 37 % were not vaccinated. Of these, 18 % would accept a J&J vaccine, 5 % would wait 1 month for a Pfizer vaccine, 25 % would wait 3 months, and 52 % would not want any vaccine. Among the unvaccinated, 56 % had heard of blood clots; 61 % of these did not want any vaccine, compared to 41 % of those who had not heard of blood clots. Moreover, among those vaccine hesitant in general, 11 % would still obtain a J&J vaccine if offered right away. These findings may suggest spillover of brand-specific adverse event concerns to the vaccine product as a whole.

"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.

When to be vaccinated? What to consider? Modelling decision-making and time preference for COVID-19 vaccine through a conjoint experiment

How do citizens choose COVID-19 vaccines, and when do they wish to be vaccinated? A choice-based conjoint experiment was conducted in Hong Kong to examine factors that shape citizens' preference toward COVID-19 vaccines and their time preference to be vaccinated, which is overlooked in extant literature. Results suggest people are most concerned about vaccines' efficacy and severe side-effects, and that cash incentives are not useful in enhancing vaccine appeal. The majority of respondents show low intention for immediate vaccination, and many of them want to delay their vaccination. Further analysis shows that their time preference is shaped more by respondent characteristics than vaccine attributes. In particular, confidence in the vaccine, trust in government, and working in high-risk professions are associated with earlier timing for vaccine uptake. Meanwhile, forced COVID testing would delay vaccination. The findings offer a novel view in understanding how people decide whether and when to receive new vaccines, which have pivotal implications for a head start of any mass vaccination programs.

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.

Estimation of Intangible Costs for Factors Associated with Oral Antiviral Drugs for COVID-19 Treatment: A Conjoint Analysis in Japan

INTRODUCTION

During the recent coronavirus disease 2019 (COVID-19) pandemic, preferences for factors associated with vaccines have been evaluated. Three oral antiviral drugs have been approved in Japan for patients with mild-to-moderate I COVID-19 symptoms. Although preferences for the drugs may also depend on various factors, these have not been fully evaluated.

METHODS

A conjoint analysis was performed based on an online survey in August 2022 to estimate the intangible costs of factors associated with oral antiviral drugs for COVID-19. Respondents were individuals aged 20-69 across Japan. The attributes included the company (Japanese/foreign) that developed the drug, formulation and size of the drug, frequency of administration per day, number of tablets/capsules per dose, number of days until no longer infectious to others, and out-of-pocket expenses. A logistic regression model was applied to estimate the utility of each level for each attribute. The intangible costs were calculated by comparing the utility to the out-of-pocket attribute.

RESULTS

Responses were collected from 11,303 participants. The difference between levels was the largest for companies that developed a drug; the intangible costs were JPY 5390 higher for the foreign company than for the Japanese company. The next largest difference was in the number of days until one is no longer infectious. For the same formulation, the intangible cost was lower for small sizes than large sizes. For similar-sized tablets and capsules, the intangible cost was lower for tablets than capsules. These tendencies were similar regardless of COVID-19 infection history and the presence of risk factors for severe COVID-19 in the respondents.

CONCLUSION

Intangible costs for factors associated with oral antiviral drugs among the Japanese population were estimated. The results may change as the number of people with a history of COVID-19 infection increases and significant progress is made regarding treatments.

The use of Health Belief Model (HBM) to explain factors underlying people to take the COVID-19 vaccine in Indonesia

BACKGROUND

SARS-COV-2 (COVID-19) has severely impacted people's health worldwide. Vaccines are one of the health measures taken to reduce the impact of COVID-19, but recent reports have revealed that some people are reluctant to be vaccinated against COVID-19. Understanding the factors underlying an individual's decision to take the COVID-19 vaccine is critical to designing an immunisation programme. This study examines factors that influence the intention to take a COVID-19 vaccine using the modified Health Belief Model (HBM) framework and analysing demographic factors.

METHOD

A cross-sectional online survey was conducted from 10 January to 20 January 2021. Five hundred thirty-seven respondents above 17 years old and residing in Indonesia voluntarily completed an online survey. Survey questions addressed sociodemographic factors; perception of susceptibility, severity, benefits and barriers; cues to action; and intention to take the COVID-19 vaccine. A Structural Equation Modelling (SEM) approach with SmartPLS software was used to analyse the measurements and model construct.

FINDINGS

The results showed that the perception of susceptibility, severity, benefits and barriers, as well as cues to action, predicted people's intention to take a COVID-19 vaccine. Model structure explained a large proportion of variance in people's intention to be vaccinated against COVID-19 (R2 = 66.8 %). Some demographic factors affected the key variables of the HBM. People with low and middle income negatively influence feeling severity, beneficial and barrier in intending to take vaccine. Other demographic factors such as sex, age, marriage and living areas did not affect the components of the HBM, except for females influencing severity and people living in urban areas associated with benefits variable. These findings imply that COVID-19 vaccination programmes should focus on providing accurate information about the severity of COVID-19 and the benefits of taking the vaccine. Building people's confidence in their ability to eliminate barriers to taking the vaccine and involving family members and community and religious leaders will increase COVID-19 vaccine uptake.

CONCLUSION

Despite limitations to the study, such as respondent demographics that are unrepresentative of the wider Indonesian population, inadequate survey timing and an exclusive focus on vaccine intention as the outcome variable, the present study contributes to explaining individuals' intentions to take a COVID-19 vaccine in a Eastern country context. This study is valuable to providing public health policy recommendations that focus on effectively designing immunisation programme interventions.

Exploring the artificial intelligence "Trust paradox": Evidence from a survey experiment in the United States

Advances in Artificial Intelligence (AI) are poised to transform society, national defense, and the economy by increasing efficiency, precision, and safety. Yet, widespread adoption within society depends on public trust and willingness to use AI-enabled technologies. In this study, we propose the possibility of an AI "trust paradox," in which individuals' willingness to use AI-enabled technologies exceeds their level of trust in these capabilities. We conduct a two-part study to explore the trust paradox. First, we conduct a conjoint analysis, varying different attributes of AI-enabled technologies in different domains-including armed drones, general surgery, police surveillance, self-driving cars, and social media content moderation-to evaluate whether and under what conditions a trust paradox may exist. Second, we use causal mediation analysis in the context of a second survey experiment to help explain why individuals use AI-enabled technologies that they do not trust. We find strong support for the trust paradox, particularly in the area of AI-enabled police surveillance, where the levels of support for its use are both higher than other domains but also significantly exceed trust. We unpack these findings to show that several underlying beliefs help account for public attitudes of support, including the fear of missing out, optimism that future versions of the technology will be more trustworthy, a belief that the benefits of AI-enabled technologies outweigh the risks, and calculation that AI-enabled technologies yield efficiency gains. Our findings have important implications for the integration of AI-enabled technologies in multiple settings.

Visual policy narrative messaging improves COVID-19 vaccine uptake

In the face of vaccine hesitancy, public health officials are seeking more effective risk communication approaches to increase vaccination rates. We test the influence of visual policy narratives on COVID-19 vaccination behavior through a panel survey experiment conducted in early 2021 (n = 3,900) and then 8 weeks later (n = 2,268). We examine the effects of three visual policy narrative messages that test the narrative mechanism of character selection (yourself, your circle, and your community) and a nonnarrative control on COVID-19 vaccine behavior. Visual risk messages that use narratives positively influence COVID-19 vaccination through serial mediation of affective response to the messages and motivation to get the COVID-19 vaccination. Additionally, character selection matters, as messages focusing on protecting others (i.e. your circle and your community) perform stronger than those of yourself. Political ideology moderated some of the effects, with conservative respondents in the nonnarrative control condition having a higher probability of vaccination in comparison to the protect yourself condition. Taken together, these results suggest that public health officials should use narrative-based visual communication messages that emphasize communal benefits of vaccinations.

The political component of COVID-19 vaccine choice: Results from a conjoint experiment

OBJECTIVES

Prior research highlights the role of efficacy, vaccine safety, and availability in vaccine hesitancy. Research is needed to better understand the political driving forces behind COVID-19 vaccine uptake. We examine the effects of the origin of a vaccine, and approval status within the EU on vaccine choice. We also test if these effects differ by party affiliation among Hungarians.

STUDY DESIGN

We use a conjoint experimental design to assess multiple causal relationships. Respondents choose between two hypothetical vaccine profiles randomly generated from 10 attributes. The data were gathered from an online panel in September 2022. We applied a quota for vaccination status and party preference. Three hundred twenty-four respondents evaluated 3888 randomly generated vaccine profiles.

METHODS

We analyse the data using an OLS estimator with standard errors clustered by respondents. To further nuance our results, we test for task, profile, and treatment heterogeneity effects.

RESULTS

By origin, respondents prefer German (MM 0.55; 95% CI 0.52-0.58) and Hungarian (0.55; 0.52-0.59) vaccines over US (0.49; 0.45-0.52) and Chinese vaccines (0.44; 0.41-0.47). By approval status, vaccines approved by the EU (0.55, 0.52-0.57) or pending authorization (0.5, 0.48-0.53) are preferred over unauthorised ones (0.45, 0.43-0.47). Both effects are conditional on party affiliation. Government voters especially prefer Hungarian vaccines (0.6; 0.55-0.65) over others.

CONCLUSIONS

The complexity of vaccination decisions calls for the usage of information shortcuts. Our findings demonstrate a strong political component that motivates vaccine choice. We demonstrate that politics and ideology have broken into fields of individual-level decisions such as health.

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.

Strengthening polio vaccine demand in Ghana: Understanding the factors influencing uptake of the vaccine and the effectiveness of different message frames

BACKGROUND

Ghana has experienced recent polio outbreaks. Behavioral insights can be used to understand behavior and create demand for the polio vaccine.

METHODS

This cross-sectional study is based on an interactive mobile phone survey that explored factors influencing the uptake of the polio vaccine among Ghanaian mothers with children younger than five years old. The survey also explores the mothers' intention to vaccinate their children in the future as well as an experiment with short polio vaccine voice message nudges to identify the most effective message frames in encouraging vaccination. The study sample was drawn from volunteers from a mobile service platform. Linear probability model regressions with Ordinary Least Squares (OLS) estimates were used to analyze the data.

RESULTS

In total, data from 708 caregivers was assessed. Out of the sample, 35% (n = 250) had not vaccinated their children against polio, around 8% (n = 53) of respondents stated they did not plan to do so, while 28% expressed intent to do so during the next polio vaccination campaign. Higher vaccination of children against polio, i.e. better uptake of the polio vaccine, appeared to be associated with children's caregivers knowing that polio causes paralysis (with a coefficient of 0.13 (95% CI: 0.02, 0.24), i.e. 13% more likely than not to have their child vaccinated). Higher vaccine uptake also appeared to be associated with the perception that the polio vaccine is safe (with a coefficient of 0.11 (95% CI: 0.01, 0.22), i.e. 11% more likely than not to have their child vaccinated). Another factor in increasing vaccine uptake is whether caregivers receive support from healthcare workers with a coefficient of 0.11 (95% CI: 0.02, 0.20), i.e. 11% more likely than not to have their child vaccinated. Crucially, difficulty accessing the polio vaccine appeared to be associate with a negative change in vaccine uptake (with a coefficient of -0.16 (95% CI: -0.23, -0.08), i.e. 16% less likely to have their child vaccinated). Satisfaction with the information provided by vaccinators was also associated with better vaccine uptake (with a coefficient of 0.12 (95% CI: 0.05, 0.20) i.e. 12% more likely than not to have their child vaccinated); and having seen or heard something negative about the polio vaccine with a coefficient of 0.10 (95% CI: 0.03, 0.17), i.e. 10% more likely than not to have their child vaccinated. The social norms message frame was statistically significant with a coefficient of 0.06 (95% CI: -0.004, 012).

CONCLUSION

The findings from this study suggest that most women with children under the age of 5 appear to have vaccinated their children against polio. Many more caregivers express an intention to vaccinate their children, never having done so before. The behavior and the intention to vaccinate are both driven by a number of factors that must be addressed to create demand for the polio vaccine. Targeted message frames appeared to be statistically significant drivers of vaccine uptake. However, more research is required to understand how they impact vaccine behavior and future intention for vaccination.

Vaccination or NPI? A conjoint analysis of German citizens' preferences in the context of the COVID-19 pandemic

This research uses discrete choice-based conjoint analysis that elicits the preference structure of German citizens when it comes to their timely intention to vaccinate. The focus is on the trade-offs between pharmaceuticals (vaccine) and "non-pharmaceutical interventions" (NPIs) such as lock-downs and social distancing measures, as well as the value of voluntary versus mandatory compliance to the citizens. Our results highlight three critical insights: (a) value of waiting: at 70% effective vaccine, 1/3 of citizens still would prefer to be vaccinated in the next 6 months rather than immediately; (b) costs of NPI constraints: an effective vaccine may come as a solution to compensate for the costs induced by invasive NPI imposed for an extended period; (c) freedom of choice: voluntary compliance is preferred by citizens over imposed measures whether it relates to vaccination choice, lock-down measures, or work location choice during the pandemic. Backing up those findings in monetary value, a quick shot of a 100% effective vaccination is estimated to be worth in the range of 11,400€. Still, the value of the shot quickly falls to no value when effectiveness drops below 50. At the same time, the cost of imposing protective rules lies in the range of 1500-2500€, depending on the rule analyzed. In comparison, the burden of extra complete lock-down and social distancing is about 775€ per citizen per month. As most current vaccines are being proven to have high efficacy, a strategy that selects the most effective vaccine candidates while emphasizing how the vaccine may stop the pain of lasting lock-downs will be appropriate to nudge the population towards vaccination. Control measures that are too restrictive may be welfare-deteriorating, but enough NPI measures must be recommended as long as vaccination adoption is not sufficiently large.

Loss-framing of information and pre-vaccination consultation improve COVID-19 vaccine acceptance: A survey experiment

Backgrounds

Vaccination remains one of the most effective ways to protect populations from COVID-19 infection, severe conditions, and death. This study aims to examine whether the gain/loss-framing of information, provision of subsidized pre-vaccination physician consultation, and cash incentives can improve COVID-19 acceptance amongst adults.

Methods

A survey experiment was conducted within a broader cross-sectional survey of people aged 18-64 years in Hong Kong, China. The participants were randomly assigned to one of the eight groups derived from full-factorial design of the three strategies with stratification by age and sex. The vaccine acceptance rate was compared between people with and without any of the strategies. The heterogeneous effects of these strategies were identified for those with different perceptions of the pandemics and vaccine in multiple logistic regressions.

Results

The survey experiment collected 1,000 valid responses. It found that loss-framed information and provision of subsidized physician consultation to assess suitability to be vaccinated, can improve vaccine acceptance, while cash incentives did not make a difference. The improvement effect of loss-framing information and physician consultation is stronger among those with higher perceived infection risk and severity of condition, as well as unvaccinated people with lower confidence in vaccine safety.

Conclusions

The findings indicated that individualized loss-framing messages and equitable provision of subsidized pre-vaccination physician consultations can be incorporated in efforts to promote vaccine acceptance and vaccination roll-out speed. However, it remains inconclusive whether and how universal cash incentives may be deployed to support vaccination promotion.

Taking a Shot: The Impact of Information Frames and Channels on Vaccination Willingness in a Pandemic

The reluctance of people to receive safe and recommended available vaccines is a well-documented public health challenge. As information and communication technologies evolve, this challenge gets more complex and even harder to manage during complex public health situations. In this experimental study, we examine the relationship between vaccine information frames (with scientific information vs. without scientific information) and channels (through government vs. religious organizations) and vaccination willingness in the U.S. in the context of a pandemic. Additionally, we evaluate the interaction between vaccine skepticism, vaccine information frames, and vaccine information channels on vaccination willingness. This experimental study uses data from Amazon Mechanical Turk (MTURK) to evaluate the relationships between vaccine skepticism, vaccine information frames, and channels on vaccination willingness. We find that contrary to our hypothesis, a vaccine advisory framed with scientific information decreases people's vaccination willingness compared to one framed without scientific information. Additionally, the impact of framing on vaccination willingness is conditioned on participants' skepticism-participants who hold skepticism toward the vaccine but received information framed with scientific information score significantly higher in vaccination willingness compared to participants who do not hold skepticism toward a vaccine. The results suggest that the factors impacting vaccination willingness are complex and nuanced. Thus, policymakers should be more strategic with the delivery of vaccination information, especially during complex health crises.

"I won't be a guinea pig": Rethinking public health communication and vaccine hesitancy in the context of COVID-19

At the beginning of 2021, when Canada started distribution of COVID-19 vaccines, the unprecedented scope and severity of the pandemic led to very high levels of public awareness and attention, with Canadians actively seeking information. We argue that while there was continuous public health communication about COVID-19 and the newly available vaccines, these messages did not address the specific anxieties elicited by the novel vaccines, even as vaccination guidelines changed. Instead, public health messages about COVID-19 vaccines resembled those aimed at reducing vaccine hesitancy for routine immunization and did not sufficiently address the constant changes to COVID-19 vaccine recommendations. In a context of heightened public concern and significant public attention, it is crucial for communicators to acknowledge that hesitancy is vaccine-specific, and that novel diseases and new vaccines produce specific concerns. Long-term strategies should address the novelty of the technology and of the risk, thoroughly explain the reasons for shifting vaccination guidelines, and leverage trusted sources, such as community leaders. Further, as COVID-19 vaccines become less effective against some of the more recent variants of the virus, vaccine messaging needs to be tailored to evolve with shifting realities to not lose productive gains in the COVID-19 vaccination campaign to date.

Biochemical and histopathological evaluation of ChAdOx1-S and BBIBP-CorV vaccination in normal and streptozotocin-induced diabetic Wistar rats

Infection with Covid-19 has been associated with some medical complications namely diabetes, thrombosis, and hepatic and renal dysfunction among others. This situation has created some concern about the use of relevant vaccines which might cause similar complications. In that regard, we planned to evaluate the impact of two of the relevant vaccines namely ChAdOx1-S and BBIBP-CorV on some of the blood biochemical factors and also on liver and kidneys functions following the immunization of healthy and streptozotocin-induced diabetic rats. Evaluation of the level of neutralizing antibody among the rats indicated that immunization with ChAdOx1-S induced a higher level of neutralizing antibody among both the healthy and diabetic rats compared to the BBIBP-CorV vaccine. Furthermore, the neutralizing antibody levels against both types of vaccines were significantly lower in diabetic rats than in healthy ones. On the other hand, no alterations were observed in the rats' sera biochemical factors, coagulation values and histopathological images of the liver and kidneys. Altogether these data besides of confirming the effectiveness of both vaccines, indicate that both vaccines have no hazardous side effects on rats and probably humans though clinical investigations are required to validate our present data.

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.

Cueing quality: Unpacking country-of-origin effects on intentions to vaccinate against COVID-19 in Taiwan

While existing studies have reported and recognized country-of-origin effects on the intentions to vaccinate against COVID-19 among individual citizens in some countries, the causal mechanism behind such effects to inform public health policymakers remain unexplored. Adding up a quality cue explanation for such effects to the existing literature, the authors argue that individual consumers are less willing to get a vaccine designed and manufactured by a country with a significantly lower quality perception than other countries. A survey experiment that recruited a nationally representative sample of Taiwanese adults (n = 1951) between December 13, 2020 and January 11, 2021 was designed and conducted to test the argument. We find that all else equal, Taiwanese respondents were on average less likely to express stronger willingness to take a vaccine from China than from the US, Germany, and Taiwan. Furthermore, even when the intrinsic quality of the vaccine was held constant by the experimental design, respondents still had a significantly lower quality perception of the vaccine from China, both in terms of perceived protection and severe side effects. Further evidence from casual mediation analyses shows that about 33% and 11% of the total average causal effects of the "China" country-of-origin label on vaccine uptake intention were respectively mediated through the perceived efficacy of protection and perceived risk of experiencing severe side effects. We conclude that quality cue constitutes one of many casual mechanisms behind widely reported country-of-origin effects on intention to vaccinate against COVID-19.

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.

The Correlates & Public Health Consequences of Prospective Vaccine Hesitancy among Individuals Who Received COVID-19 Vaccine Boosters in the U.S

Supplemental “booster” vaccines may prove vital in combating variant waves of endemic COVID-19. Given relatively low levels of booster vaccine uptake, Americans’ willingness to receive a second booster shot is unclear. In a demographically representative survey of N = 3950 US adults (limited to a “boosted” subsample of N = 1551 who had not yet received a second booster), 49% [95% CI: 47, 51] of Americans report having received an initial booster shot, while just 34% [33, 36] report that they would be “very likely” to do so again. Concerns about missing work to vaccinate (−10%; B = 0.53, p = 0.05) and being unconvinced that additional boosters will be necessary (−47%; B = 2.24, p < 0.01) are significantly and negatively associated with being very likely to receive a second COVID-19 booster. These findings can help inform discussions about policies aimed at increasing vaccine uptake in the U.S., and broaden researchers’ understanding of vaccine reluctance among those who might otherwise hold positive views toward vaccination.

Misinformation, Anticipated Regret, and Vaccine-Related Behaviors

A national survey (N = 1025) conducted in August 2021 reveals that Americans' belief in misinformation about COVID-19 was negatively associated with vaccine acceptance. Importantly, the more participants believe in misinformation, the less anticipated regret they experience for not getting vaccinated. Reduced anticipated regret is associated with lower levels of vaccination intention and vaccine acceptance. To counteract the negative impact of misinformation, this study reveals the potential of an under-researched emotion in overcoming vaccine hesitancy.

The citizen preferences-positive externality trade-off: A survey study of COVID-19 vaccine deployment in Japan

Objective

Medicine is a scarce resource and a public good that benefits others by bettering patients’ health. COVID-19 vaccines in shortage are, 1) a scarce resource and 2) a public good with the positive externality of building herd immunity. These features are expected to drive citizens’ attitudes in opposite directions, exclusionist and inclusionist, respectively. Scarcity would drive citizens’ exclusionism, while the positive externality might mitigate exclusionism.

Setting and design

We recruited 15,000 Japanese adults and asked them to rank, in the context of a COVID-19 vaccine shortage, the deservingness of hypothetical vaccine recipients who differed according to 1) citizenship status, 2) visa type and duration of stay (if foreign), 3) occupation, 4) age, 5) whether they lived with a child, and 6) whether they lived with an elderly individual. Citizenship options were Japanese, Chinese, Taiwanese, South Korean, American, or European. The occupations were healthcare, education, other employed, self-employed, or not employed. The 6 attributes were randomly combined, and respondents were shown 3 hypothetical vaccine recipients: one was Japanese, and the others were foreigners.

Treatments

First, through a conjoint design, we created hypothetical vaccine recipients whose attributes were randomized except for the benchmark citizenship, Japanese national. Second, we randomly presented two scenarios for vaccination payments: 1) billed at cost or 2) fully subsidized by the government.

Results

1) Whether the vaccines were billed at cost or fully subsidized did not affect the rankings of deservingness. 2) Japanese citizenship was prioritized. 3) The penalty for being a foreigner was higher for individuals from nations with which Japan has geopolitical tensions. 4) Working in health or education reduced the penalty on foreigners, indicating that the positive externality related to occupation amplifies the positive externality associated with vaccination and mitigates exclusionist attitudes.

Conclusions

The positive occupational externalities that amplify the positive externality of vaccination substantially allay the foreigner penalty.

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.

South African University Staff and Students’ Perspectives, Preferences, and Drivers of Hesitancy Regarding COVID-19 Vaccines: A Multi-Methods Study

COVID-19 vaccine hesitancy poses a threat to the success of vaccination programmes currently being implemented. Concerns regarding vaccine effectiveness and vaccine-related adverse events are potential barriers to vaccination; however, it remains unclear whether tailored messaging and vaccination programmes can influence uptake. Understanding the preferences of key groups, including students, could guide the implementation of youth-targeted COVID-19 vaccination programmes, ensuring optimal uptake. This study examined university staff and students’ perspectives, preferences, and drivers of hesitancy regarding COVID-19 vaccines. A multi-methods approach was used—an online convenience sample survey and discrete choice experiment (DCE)—targeting staff and students at the University of KwaZulu-Natal, South Africa. The survey and DCE were available for staff and students, and data were collected from 18 November to 24 December 2021. The survey captured demographic characteristics as well as attitudes and perspectives of COVID-19 and available vaccines using modified Likert rating questions adapted from previously used tools. The DCE was embedded within the survey tool and varied critical COVID-19 vaccine programme characteristics to calculate relative utilities (preferences) and determine trade-offs. A total of 1836 staff and students participated in the study (541 staff, 1262 students, 33 undisclosed). A total of 1145 (62%) respondents reported that they had been vaccinated against COVID-19. Vaccination against COVID-19 was less prevalent among students compared with staff (79% of staff vs. 57% of students). The vaccine’s effectiveness (22%), and its safety (21%), ranked as the two dominant reasons for not getting vaccinated. These concerns were also evident from the DCE, with staff and students being significantly influenced by vaccine effectiveness, with participants preferring highly effective vaccines (90% effective) as compared with those listed as being 70% or 50% effective (β = −3.72, 95% CI = −4.39 to −3.04); this characteristic had the strongest effect on preferences of any attribute. The frequency of vaccination doses was also found to have a significant effect on preferences with participants deriving less utility from choice alternatives requiring two initial vaccine doses compared with one dose (β = −1.00, 95% CI = −1.42 to −0.58) or annual boosters compared with none (β = −2.35, 95% CI = −2.85 to −1.86). Notably, an incentive of ZAR 350 (USD 23.28) did have a positive utility (β = 1.14, 95% CI = 0.76 to 1.53) as compared with no incentive. Given the slow take-up of vaccination among youth in South Africa, this study offers valuable insights into the factors that drive hesitancy among this population. Concerns have been raised around the safety and effectiveness of vaccines, although there remains a predilection for efficient services. Respondents were not enthusiastic about the prospect of having to take boosters, and this has played out in the roll-out data. Financial incentives may increase both the uptake of the initial dose of vaccines and see a more favourable response to subsequent boosters. Universities should consider tailored messaging regarding vaccine effectiveness and facilitate access to vaccines, to align services with the stated preferences of staff and students.

Acceptance and willingness to purchase a hypothetical COVID-19 vaccine in a region under Shariah law: A cross-sectional study in Aceh, Indonesia

Vaccines are urgently needed to control the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to determine the acceptance of and willingness to purchase a hypothetical COVID-19 vaccine in the general population of Aceh, a holistic Shariah law implementation province in Indonesia. An online cross-sectional study was conducted using a quota sampling technique between 1 to 24 September 2021. To determine hypothetical vaccine acceptance, respondents were asked if they were willing to accept vaccines with combinations of either 50% or 95% effectiveness and either 5% or 20% risk of adverse effects. Willingness to purchase was assessed by asking whether the participants would pay for such vaccines at certain price points. Logistic regression analysis was used to assess the associated determinants. Out of 377 respondents included in the final analysis, 86.5% were willing to accept a COVID-19 vaccine with 95% effectiveness and 5% adverse effects. The acceptance rate dropped to 45.1% if the risk of adverse effects was 20%. Vaccines with 50% effectiveness and 5% adverse effects were acceptable to 42.2% but the acceptance went down to 17.2% if the risk of adverse effects increased to 20%. Multivariate analysis found that men were twice as likely to accept a vaccine with 95% effectiveness and 5% adverse effects compared to females (aOR: 2.01; 95% CI 1.05-3.86). We found that 156/377 (41.3%) of respondents were willing to purchase a COVID-19 vaccine and of these participants 71.1% were willing to pay between Indonesian Rupiah (IDR) 50,000-150,000 (US$ 3.33-10.00). In conclusion, the acceptance rate of a hypothetical COVID-19 vaccine varied based on effectiveness and the risk of adverse effects.

Public Preferences for Policies to Promote COVID-19 Vaccination Uptake: A Discrete Choice Experiment in The Netherlands

OBJECTIVES

The COVID-19 pandemic forms an unprecedented public health, economic, and social crisis. Uptake of vaccination is critical for controlling the pandemic. Nevertheless, vaccination hesitancy is considerable, requiring policies to promote uptake. We investigate Dutch citizens' preferences for policies that aim to promote vaccination through facilitating choice of vaccination, profiling it as the norm, making vaccination more attractive through rewards, or punishing people who reject vaccination.

METHODS

We conducted a discrete choice experiment in which 747 respondents were asked to choose between policies to promote vaccination uptake and their impacts on the number of deaths, people with permanent health problems, households with income loss, and a tax increase.

RESULTS

Respondents generally had a negative preference for policies that promote vaccination. They particularly disliked policies that punish those who reject the vaccine and were more favorable toward policies that reward vaccination, such as awarding additional rights to vaccinated individuals through vaccination passports. Respondents who reject vaccination were in general much more negative about the policy options than respondents who consider accepting the vaccine. Nevertheless, vaccination passports are supported by both respondents who accept the vaccine, those who reject vaccination, and those who are unsure about vaccination.

CONCLUSIONS

This study provides concrete directions for governments attempting to increase the vaccination uptake in ways that are supported by the public. Our results could encourage policy makers to focus on policy options that make vaccination easier and reward people who take the vaccine, as especially the implementation of vaccination passports was supported.

To vaccinate or not: The relationship between conscientiousness and individual attitudes toward vaccination in real-life contexts

Despite the availability of a safe and effective vaccine being well-recognized as a critical tool to end the COVID-19 pandemic, many individuals remain vaccine hesitant for various reasons. In the literature, one well-established finding is that skeptical attitudes towards vaccination are higher amongst individuals low in conscientiousness. However, no research is available to corroborate whether the relationship between conscientiousness and intention to vaccinate has force in real life. The present research investigated whether, in addition to self-reported conscientiousness, objectively observable index of conscientiousness behaviors is related to individual perception of vaccination. Based on self-reported data, Study 1 fully replicated prior findings that higher levels of conscientiousness are associated with more positive attitudes towards vaccination in a Chinese student sample. Using the time of arrival for an appointment as a proxy measure for conscientiousness behaviors, Study 2 revealed that non-student adults who arrived early to appointments showed stronger COVID-vaccine uptake intentions than those who arrived late to appointments. Moving beyond vaccination intention to actual behavior, Study 3 found that the arrival punctuality rates of vaccinated participants were higher than those of unvaccinated participants. Overall, our research highlights the important role of conscientiousness-related traits in individuals' COVID-19 vaccination attitudes and behavior.

Personal and contextual determinants of COVID-19 vaccination intention: a vignette study

BACKGROUND

This vignette study explores which factors contribute to higher COVID-19 vaccination intentions.

METHODS

Between the 4^th-11 January 2021, we recruited 15,901 Belgian citizens (M_age = 50.11 years, range 18-100) through convenience sampling to participate in a vignette study. In each vignette, we manipulated contextual determinants consisting of different factors. Each participant rated six vignettes in terms of the outcomes 'vaccination intention' and 'recommendation to others.' Finally, we explored the benefits of tailored communication by examining whether these ratings depended upon citizens' initial motives for vaccination.

RESULTS

Participants are most likely to accept a vaccine when they expect no or only small side effects, when the vaccine offers a 95% protection, and when people can no longer infect others (p < 0.001). The possibility to receive the vaccine at home or at the GP's office, highlighting that most citizens are willing to get vaccinated, and emphasizing the protective benefits for others yielded additional positive effects (p < 0.001). Results showed that tailored communication has a small but significant effect, especially for individuals high on distrust-based amotivation (p < 0.01).

CONCLUSION

In addition to vaccine characteristics, there is room for policymakers to respond to those determinants that fall under their control and can thus be highlighted within communication campaigns.

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.

COVID-19 vaccine hesitancy and vaccine passports: a cross-sectional conjoint experiment in Japan

OBJECTIVES

While the development of vaccines against the Novel Coronavirus (COVID-19) brought hope of establishing herd immunity and ending the global pandemic, vaccine hesitancy can hinder the progress towards herd immunity. In this study, by analysing the data collected when citizens undergo public health restrictions due to the pandemic, we assess the determinants of vaccine hesitancy, reasons for hesitation and potential effectiveness of vaccine passports used to relax public health restrictions on mitigating vaccine hesitancy.

DESIGN

Cross-sectional study, longitudinal study and conjoint experimental design.

SETTING

An online survey conducted in Japan in July 2021.

PARTICIPANTS

A demographically representative sample of 5000 Japanese adults aged 20-74.

PRIMARY OUTCOME MEASURES

COVID-19 vaccination intention RESULTS: We found that about 30% of respondents did not intend to get vaccinated or had not yet decided, with major reasons for vaccine hesitancy relating to concerns about the safety and side effects of the vaccine. In line with previous findings, younger age, lower socioeconomic status, and psychological and behavioural factors such as weaker COVID-19 fear were associated with vaccine hesitancy. Easing of public health restrictions such as travel, wearing face masks and dining out at night was associated with an increase in vaccine acceptance by 4%-10%. Moreover, we found that more than 90% of respondents who intended to get vaccinated actually received it while smaller proportions among those undecided and unwilling to get vaccinated did so.

CONCLUSION

With a major concern about vaccine safety and side effects, interventions to mitigate against these may help to reduce vaccine hesitancy. Moreover, when citizens are imposed with restrictions, vaccine passports that increase their freedom may be helpful to increase vaccination rates.

Preference analysis on the online learning attributes among senior high school students during the COVID-19 pandemic: A conjoint analysis approach

The COVID-19 pandemic has resulted in the shift from face-to-face to fully online learning. The purpose of this study was to evaluate the preference of senior high school students on online learning attributes during the COVID-19 pandemic by utilizing a conjoint analysis approach. Six attributes which consist of delivery type, assigned tasks, evaluation, virtual laboratory, interface layout, and delivery platform were simultaneously analyzed through orthogonal design. A total of 1189 senior high school students were collected via purposive sampling approach through the social media platform. The respondents voluntarily participated and answered 29 stimuli with 2 holdouts generated by using SPSS 25 utilizing a 7-point Likert scale. The results indicated that evaluation was found to be the most significant attribute and followed by virtual laboratory, delivery type, and delivery platform. Interestingly, multiple choice evaluation, not requiring virtual laboratories, mixed delivery type (synchronous with recorded lectures), and MS Teams as delivery platform were considered as the keys for the preference. This study is the first study that utilized a conjoint approach to analyze the senior high school students' preference on the online learning attributes during the COVID-19 pandemic. Finally, the conjoint approach can be applied and extended to evaluate the online learning attributes globally by utilizing the attributes and design created in this study.

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.

Assessing the impact of novelty and conformity on hesitancy towards COVID-19 vaccines using mRNA technology

Background

Public hesitancy towards Covid-19 vaccines remains a major hurdle for mass vaccination programs today. While mRNA vaccines are more efficacious than conventional vaccines, it is unknown how much the novelty of this technology increases hesitancy.

Methods

We quantify this “novelty penalty” in a large online experiment with 35,173 adults in nine countries. Subjects were randomly selected and assigned to one of two vaccine groups (conventional or mRNA), and one of five hypothetical inoculation rate groups (0%, 20%, 40%, 60%, or 80%). Subjects reported their willingness to accept the Covid-19 vaccine on a five-point Likert scale.

Results

The novelty of the mRNA vaccine technology reduces the odds of a higher level of vaccine acceptance by 14.2% (odds ratio 0.858; p < 0.001). On the other hand, we find that social conformity reduces vaccine hesitancy. At a 0% inoculation rate, 31.7% report that they are “very likely” to get a mRNA vaccine while at a 20% inoculation rate, willingness jumps to 49.6%.

Conclusions

The novelty of the mRNA vaccine increases hesitancy, but social conformity reduces it. A small group of early adopters can provide momentum for vaccination.

Vaccine hesitancy is a delay in acceptance or refusal of vaccines despite these being available. The hesitancy of the general public towards Covid-19 vaccines remains a challenge for mass vaccination programs. While Covid-19 vaccines using mRNA technology are more effective than vaccines produced using conventional technology, it is unknown how the novelty of the mRNA technology affects vaccine hesitancy among members of the public. Here, we surveyed over 35,000 adults from nine countries and found that the new mRNA vaccine technology leads to greater vaccine hesitancy. However, people are much more willing to accept the vaccine if at least 20% of the population has already received it. These findings show that while the novelty of the mRNA vaccine increases hesitancy, this hesitancy can be reduced by the presence of a small group of early adopters.

Leong et al. surveyed more than 35,000 participants in nine countries to assess the impact of novelty and conformity on mRNA Covid-19 vaccine hesitancy. They show that the use of mRNA vaccine technology increases the odds of vaccine hesitancy significantly while social conformity reduces it.

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.

Facilitating free and paid vaccine acceptance in Malaysia: effectiveness of vaccine and fear of COVID-19

Purpose

This study aims to examine how demographic and psychological predictors of free and paid vaccine acceptance operate within an infectious environment. The psychological predictors were derived from the protection motivation theory (PMT), including the appraised effectiveness of vaccine in containing the pandemic and the fear of COVID-19.

Design/methodology/approach

A representative data set that consists of responses from 2,850 Malaysians was used in this study. Multi-level modelling was used to analyse the data.

Findings

Results indicated that the acceptance of free and paid vaccination did not differ by region. This suggests that the effects of the included psychological predictors on vaccine acceptance are independent from the environment. Malaysians are more likely to endorse both free and paid vaccination when it is perceived as effective in controlling the pandemic. When the vaccine is deemed as an effective preventive of COVID-19, Malaysians tend to seek free vaccination. Although fear of COVID-19 did significantly predict the endorsement of vaccination, it is a weaker predictor than the perceived effectiveness of vaccine.

Originality/value

This research used a large representative data set and the PMT framework in addressing vaccine acceptance in Malaysia.

Qualitative examination of the attitudes of healthcare workers in Turkey regarding COVID-19 vaccines

PURPOSE

The attitudes of healthcare workers toward COVID-19 vaccines ensure that health services are able to run without interruption and potentially have a role in the messaging about vaccination that they convey to the public. Hence, healthcare workers' attitudes ultimately have a significant role in controlling the pandemic. This study aimed to qualitatively investigate the attitudes of healthcare workers in Turkey in relation to COVID-19 vaccines.

METHODS

The study used the phenomenological approach. The sample consisted of 36 healthcare workers who were employed during the COVID-19 pandemic. Data were collected online using focus group interviews. A total of four focus group interviews were conducted.

FINDINGS

Following analysis of the data, the attitudes of healthcare workers in Turkey toward the COVID-19 vaccine were divided into three themes: "influencing factors," "priority group" and "trust."

CONCLUSIONS

Vaccination was found to create negative emotions among some of the healthcare workers. Their opinions about the COVID-19 vaccines were affected by the negative emotions and burnout they experienced during the pandemic. In addition, they saw the vaccination process as impacted by contraindications and uncertainty about the duration of the protection, the balance of the benefits and harm of the vaccines, and by vaccine myths and prejudices about the country where the vaccine was developed. Healthcare professionals expressed the need for trust to be established in the whole vaccination process. They suggested that different vaccine options should be offered, that the appointment and process notification system for vaccination should be improved, that evidence-based information about vaccines should be provided and that a safe environment should be created.

PRACTICE IMPLICATIONS

Vaccine hesitancy can be addressed by careful attention to the application of vaccination programs, correct and effective use of social media, transparent, and precise management of political processes, and the provision of evidence-based information about the vaccines.

The path towards herd immunity: Predicting COVID-19 vaccination uptake through results from a stated choice study across six continents

Despite unprecedented progress in developing COVID-19 vaccines, global vaccination levels needed to reach herd immunity remain a distant target, while new variants keep emerging. Obtaining near universal vaccine uptake relies on understanding and addressing vaccine resistance. Simple questions about vaccine acceptance however ignore that the vaccines being offered vary across countries and even population subgroups, and differ in terms of efficacy and side effects. By using advanced discrete choice models estimated on stated choice data collected in 18 countries/territories across six continents, we show a substantial influence of vaccine characteristics. Uptake increases if more efficacious vaccines (95% vs 60%) are offered (mean across study areas = 3.9%, range of 0.6%-8.1%) or if vaccines offer at least 12 months of protection (mean across study areas = 2.4%, range of 0.2%-5.8%), while an increase in severe side effects (from 0.001% to 0.01%) leads to reduced uptake (mean = -1.3%, range of -0.2% to -3.9%). Additionally, a large share of individuals (mean = 55.2%, range of 28%-75.8%) would delay vaccination by 3 months to obtain a more efficacious (95% vs 60%) vaccine, where this increases further if the low efficacy vaccine has a higher risk (0.01% instead of 0.001%) of severe side effects (mean = 65.9%, range of 41.4%-86.5%). Our work highlights that careful consideration of which vaccines to offer can be beneficial. In support of this, we provide an interactive tool to predict uptake in a country as a function of the vaccines being deployed, and also depending on the levels of infectiousness and severity of circulating variants of COVID-19.

Communication about vaccine efficacy and COVID-19 vaccine choice: Evidence from a survey experiment in the United States

While mass vaccination campaigns against COVID-19 have inoculated almost 200 million Americans and billions more worldwide, significant pockets of vaccine hesitancy remain. Research has firmly established that vaccine efficacy is an important driver of public vaccine acceptance and choice. However, current vaccines offer widely varying levels of protection against different adverse health outcomes of COVID-19. This study employs an experiment embedded on a survey of 1,194 US adults in June 2021 to examine how communications about vaccine efficacy affect vaccine choice. The experiment manipulated how vaccine efficacy was defined across four treatments: (1) protection against symptomatic infection; (2) protection against severe illness; (3) protection against hospitalization/death; (4) efficacy data on all three metrics. The control group received no efficacy information. Subjects were asked to choose between a pair of vaccines-a one-dose viral vector vaccine or two-dose mRNA vaccine-whose efficacy data varied across the four experimental treatment groups. Efficacy data for each vaccine on each dimension were adapted from clinical trial data on the Johnson & Johnson/Janssen and Pfizer/BioNTech vaccines. Among all respondents, only modest preference gaps between the two vaccines emerged in the control group and when the two vaccines' roughly equivalent efficacy data against hospitalization and death were reported. Strong preferences for a two-dose mRNA vaccine emerged in treatments where its higher efficacy against symptomatic or severe illness was reported, as well as in the treatment where data on all three efficacy criteria were reported. Unvaccinated respondents preferred a one-dose viral vector vaccine when only efficacy data against hospitalization or death was presented. Black and Latino respondents were significantly more likely to choose the one-shot viral vector vaccine in the combined efficacy treatment than were whites. Results speak to the importance of understanding how communications about vaccine efficacy affect public preferences in an era of increasing uncertainty about efficacy against variants.

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.

The social gradient in COVID-19 vaccination intentions and the role of solidarity beliefs among adolescents

BACKGROUND

Vaccines against COVID-19 play a prominent role in the policies enacted to combat the pandemic. However, vaccination rates are lowest among adolescents and young adults. Therefore, research on younger individuals is needed to provide a deeper understanding of social disparities and the motives behind vaccination intentions.

METHODS

This study draws on a sample (N = 4079) of German high school students and graduates. Based on cross-sectional data from March to July 2021 and linear regression models, which are conditioned on personality, risk preferences, and trust, the study analyses social disparities (i.e., gender, parental education and migration background) in vaccination intentions.

RESULTS

We do not find heterogeneity by gender. Individuals with low-educated parents and a migration background indicate below-average levels of vaccination intention. Differences in solidarity beliefs entirely explain the heterogeneity between individuals with low-educated parents and those with high-educated parents. While differences in beliefs explain a substantial part of the heterogeneity in vaccination intentions, cultural and monetary resources also constitute an important source of difference in vaccination intentions between individuals with and without a migration background. These results are important because our data indicate higher infection risks among individuals with a migration and low education background. Additionally, individuals from lower social origins and with migration backgrounds report higher levels of perceived burdens associated with COVID-19-related policies. The migration results differ between first- and second-generation migrants and by region of origin.

CONCLUSION

Polarization in solidarity explains social gradients in vaccination intention. A solidarity narrative may not motivate a significant share of young individuals to be vaccinated.

Public Preferences for a COVID-19 Vaccination Program in Quebec: A Discrete Choice Experiment

OBJECTIVES

We aimed to elicit preferences of the French-speaking Quebec population regarding a COVID-19 vaccination program and to characterize individuals with respect to their vaccination behaviors.

METHODS

A discrete choice experiment was conducted in Autumn 2020 via a web-based survey. Its design included seven attributes: vaccine origin, vaccine effectiveness, side effects, protection duration, priority population, waiting time to get vaccinated, and recommender of the vaccine. Utilities were estimated using a mixed-logit model and a latent class logit model.

RESULTS

Our sample included 1599 individuals. From this total, 119 always chose the opt-out option (7.4%). According to the mixed-logit model, the relative weights of attributes were as follows: effectiveness (28.48%), side effects (23.68%), protection duration (17.41%), vaccine origin (12.75%), recommender (11.96%), waiting time to get vaccinated (3.62%), and priority population (2.11%). Five classes were derived from the latent class logit model. Class 1 (9.13%) wanted to get vaccinated as fast as possible and was composed of uncertain and more vulnerable individuals. Class 5 (25.14%) was similar to the full sample, mostly favoring vaccination. Classes 2 (7.69%) and 4 (15.82%) included "vaccine hesitant and demanding" individuals but were different in their sociodemographic profiles. Finally, "anti-vaccine" and other "vaccine hesitant" individuals were in class 3 (42.21%).

CONCLUSIONS

This study showed the vaccine characteristics that are likely to improve vaccine uptake, which may more easily lead to herd immunity. Different profiles of respondents also showed various levels of acceptance toward a COVID-19 vaccination program, which may help to better understand vaccine hesitancy behaviors.

Establishment and Evaluation of Scalable COVID-19 Vaccine Clinics at a Large University

Background

Previous large-scale vaccination clinics have been successful before the coronavirus disease 2019 (COVID-19) pandemic; however, owing to the strict storage requirements and pharmaceutical preparation needed for the COVID-19 vaccines, careful thought and planning were necessary to successfully deploy these clinics immediately after vaccine availability. The focus of this manuscript is to describe the development and implementation of COVID-19 vaccination clinics in a large public university, using professionals from within and outside of its health sciences schools.

Objectives

The primary objective of this project was to (1) implement COVID-19 vaccination clinics for university faculty, staff, students, and community members. Additional objectives of the clinics were to (2) actively incorporate pharmacy, nursing, and medical students into the clinic workflow; (3) promote interprofessional collaboration among faculty and students; and (4) assess patient satisfaction.

Practice description

The School of Pharmacy faculty, in conjunction with the Office of Strategic Initiatives, planned and coordinated COVID-19 vaccination clinics from December 2020 to July 2021. Students and faculty from schools of pharmacy, nursing, and medicine were used. COVID-19 vaccinations were offered to university faculty, staff, and students and community members based on the Centers for Disease Control and Prevention priority groups. The clinic processes were designed such that they could be scaled from 100 to 2,000 participants per day.

Practice innovation

The School of Pharmacy led approach was adjustable depending on the number of patients, continuously monitored and adaptable. The importance of pharmacists as part of the interprofessional health care team was exemplified by faculty and students involved.

Evaluation methods

All patients receiving COVID-19 vaccinations at the clinics were e-mailed anonymous surveys for assessment of the quality of the vaccination encounter after completion of their primary vaccine series.

Results

More than 15,000 COVID-19 vaccinations were provided through the clinics from December 2020 to July 2021. Professional staffing totaled 3352 hours for the 48 clinics. Thirty-eight percent of the vaccinated patients responded to the clinic satisfaction survey with predominately excellent ratings.

Conclusion

COVID-19 vaccination clinics can be successfully planned and implemented in a scalable fashion in a large university setting using an interprofessional team approach.

Listening to vaccine refusers

In bioethics vaccine refusal is often discussed as an instance of free riding on the herd immunity of an infectious disease. However, the social science of vaccine refusal suggests that the reasoning behind refusal to vaccinate more often stems from previous negative experiences in healthcare practice as well as deeply felt distrust of healthcare institutions. Moreover, vaccine refusal often acts like an exit mechanism. Whilst free riding is often met with sanctions, exit, according to Albert Hirschman's theory of exit and voice is most efficiently met by addressing concerns and increasing the quality and number of feedback channels. If the legitimate grievances responsible for vaccine refusal are not heard or addressed by healthcare policy, further polarization of attitudes to vaccines is likely to ensue. Thus, there is a need in the bioethics of vaccine refusal to understand the diverse ethical questions of this inflammable issue in addition to those of individual responsibility to vaccinate.

Factors Affecting Young Adults' Decision Making to Undergo COVID-19 Vaccination: A Patient Preference Study

Young adults are a substantial driver of lagging vaccination against COVID-19 worldwide. We aimed to understand what vaccine or vaccination environment attributes may affect young adults' vaccine inclination. We contacted a convenience sample of 1415 students to recruit a minimum of 150 individuals for a web-based discrete choice experiment. The respondents were asked to choose one of two hypothetical vaccines, defined by six attributes-vaccine efficacy, risk of mild side effects, protection duration, administration route, recommender, and travel time to the vaccination site. Individual preferences were calculated with the Markov chain Monte Carlo hierarchical Bayes estimation. A total of 445 individuals (mean age 24.4 years, 272 (61.1%) women) completed the survey between 22 March and 3 May 2021. Vaccine protection duration (28.3 (95% CI, 27.0-29.6)) and vaccine efficacy in preventing COVID-19 (27.5 (95% CI, 26.3-28.8)) were the most important, followed by the risk of vaccine side effects (17.3 (95% CI, 16.2-18.4)). Individuals reluctant or unsure about vaccination (21.1%) prioritized the potential for mild side effects higher and vaccine efficacy lower than the vaccine-inclined individuals. New vaccination programs that target young adults should emphasize the protection duration, low risk of vaccine side effects, and high efficacy.