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

COVID-19 Vaccine Preferences in General Populations in Canada, Germany, the United Kingdom, and the United States: Discrete Choice Experiment

BACKGROUND

Despite strong evidence supporting COVID-19 vaccine efficacy and safety, a proportion of the population remains hesitant to receive immunization. Discrete choice experiments (DCEs) can help assess preferences and decision-making drivers.

OBJECTIVE

We aim to (1) elicit preferences for COVID-19 vaccines in Canada, Germany, the United Kingdom, and the United States; (2) understand which vaccine attributes people there value; and (3) gain insight into the choices that different population subgroups make regarding COVID-19 vaccines.

METHODS

Participants in the 2019nCoV-408 study were aged ≥18 years; self-reported antivaccinationists were excluded. A DCE with a series of 2 hypothetical vaccine options was embedded into a survey to determine participant treatment preferences (primary objective). Survey questions covered vaccine preference, previous COVID-19 experiences, and demographics, which were summarized using descriptive statistics to understand the study participants' backgrounds. In the DCE, participants were provided choice pairs: 1 set with and 1 without an "opt-out" option. Each participant viewed 11 unique vaccine profiles. Vaccine attributes consisted of type (messenger RNA or protein), level of protection against any or severe COVID-19, risk of side effects (common and serious), and potential coadministration of COVID-19 and influenza vaccines. Attribute level selections were included for protection and safety (degree of effectiveness and side effect risk, respectively). Participants were stratified by vaccination status (unvaccinated, or partially or fully vaccinated) and disease risk group (high-risk or non-high-risk). A conditional logit model was used to analyze DCE data to estimate preferences of vaccine attributes, with the percentage relative importance calculated to allow for its ranking. Each model was run twice to account for sets with and without the opt-out options.

RESULTS

The mean age of participants (N=2000) was 48 (SD 18.8) years, and 51.25% (1025/2000) were male. The DCE revealed that the most important COVID-19 vaccine attributes were protection against severe COVID-19 or any severity of COVID-19 and common side effects. Protection against severe COVID-19 was the most important attribute for fully vaccinated participants, which significantly differed from the unvaccinated or partially vaccinated subgroup (relative importance 34.8% vs 30.6%; P=.049). Avoiding serious vaccine side effects was a significantly higher priority for the unvaccinated or partially versus fully vaccinated subgroup (relative importance 10.7% vs 8.2%; P=.044). Attributes with significant differences in the relative importance between the high-risk versus non-high-risk subgroups were protection against severe COVID-19 (38.2% vs 31.5%; P<.000), avoiding common vaccine side effects (12% vs 20.5%; P<.000), and avoiding serious vaccine side effects (9.7% vs 7.5%; P=.002).

CONCLUSIONS

This DCE identified COVID-19 vaccine attributes, such as protection against severe COVID-19, that may influence preference and drive choice and can inform vaccine strategies. The high ranking of common and serious vaccine side effects suggests that, when the efficacy of 2 vaccines is comparable, safety is a key decision-making factor.

Preferences for COVID-19 Vaccines: Systematic Literature Review of Discrete Choice Experiments

BACKGROUND

Vaccination can be viewed as comprising the most important defensive barriers to protect susceptible groups from infection. However, vaccine hesitancy for COVID-19 is widespread worldwide.

OBJECTIVE

We aimed to systematically review studies eliciting the COVID-19 vaccine preference using discrete choice experiments.

METHODS

A literature search was conducted in PubMed, Embase, Web of Science, Scopus, and CINAHL Plus platforms in April 2023. Search terms included discrete choice experiments, COVID-19, and vaccines and related synonyms. Descriptive statistics were used to summarize the study characteristics. Subgroup analyses were performed by factors such as high-income countries and low- and middle-income countries and study period (before, during, and after the pandemic wave). Quality appraisal was performed using the 5-item Purpose, Respondents, Explanation, Findings, and Significance checklist.

RESULTS

The search yield a total of 623 records, and 47 studies with 53 data points were finally included. Attributes were grouped into 4 categories: outcome, process, cost, and others. The vaccine effectiveness (21/53, 40%) and safety (7/53, 13%) were the most frequently reported and important attributes. Subgroup analyses showed that vaccine effectiveness was the most important attribute, although the preference varied by subgroups. Compared to high-income countries (3/29, 10%), a higher proportion of low- and middle-income countries (4/24, 17%) prioritized safety. As the pandemic progressed, the duration of protection (2/24, 8%) during the pandemic wave and COVID-19 mortality risk (5/25, 20%) after the pandemic wave emerged as 2 of the most important attributes.

CONCLUSIONS

Our review revealed the critical role of vaccine effectiveness and safety in COVID-19 vaccine preference. However, it should be noticed that preference heterogeneity was observed across subpopulations and may change over time.

TRIAL REGISTRATION

PROSPERO CRD42023422720; https://tinyurl.com/2etf7ny7.

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.

Jumping the Queue:Willingness to Pay for Faster Access to COVID-19 Vaccines in Seven European Countries

INTRODUCTION

Given the initial shortage of vaccines to protect against coronavirus disease 2019 (COVID-19), many countries set up priority lists, implying that large parts of the population had to wait. We therefore elicited the willingness to pay (WTP) for access to two hypothetical COVID-19 vaccines.

METHODS

Respondents were asked how much they would be willing to pay to get an immediate COVID-19 vaccination rather than waiting for one through the public system. We report data collected in January/February 2021 from the European COVID Survey (ECOS) comprising representative samples of the population in Denmark, France, Germany, Italy, Portugal, the Netherlands, and the UK (N = 7068).

RESULTS

In total, 73% (68.5%) of respondents were willing to pay for immediate access to a 100% (60%) effective vaccine, ranging from 66.4% (59.4%) in the Netherlands to 83.3% (81.1%) in Portugal. We found a mean WTP of 54.36 euros (median 37 euros) for immediate access to the 100% effective COVID-19 vaccine and 43.83 euros (median 31 euros) for the 60% effective vaccine. The vaccines' effectiveness, respondents' age, country of residence, income, health state and well-being were significant determinants of WTP. Willingness to be vaccinated (WTV) was also strongly associated with WTP, with lower WTV being associated with lower WTP. A higher perceived risk of infection, higher health risk, more trust in the safety of vaccines, and higher expected waiting time for the free vaccination were all associated with a higher WTP.

CONCLUSION

We find that most respondents would have been willing to pay for faster access to COVID vaccines (jumping the queue), suggesting welfare gains from quicker access to these vaccines. This is an important result in light of potential future outbreaks and vaccines.

Prevalence and factors related to COVID-19 vaccine hesitancy and unwillingness in Canada: A systematic review and meta-analysis

This systematic review and meta-analysis examined the prevalence and factors associated with vaccine hesitancy and vaccine unwillingness in Canada. Eleven databases were searched in March 2022. The pooled prevalence of coronavirus disease 2019 (COVID-19) vaccine hesitancy and unwillingness was estimated. Subgroup analyses and meta-regressions were performed. Out of 667 studies screened, 86 full-text articles were reviewed, and 30 were included in the systematic review. Twenty-four articles were included in the meta-analysis; 12 for the pooled prevalence of vaccine hesitancy (42.3% [95% CI, 33.7%-51.0%]) and 12 for vaccine unwillingness (20.1% [95% CI, 15.2%-24.9%]). Vaccine hesitancy was higher in females (18.3% [95% CI, 12.4%-24.2%]) than males (13.9% [95% CI, 9.0%-18.8%]), and in rural (16.3% [95% CI, 12.9%-19.7%]) versus urban areas (14.1% [95%CI, 9.9%-18.3%]). Vaccine unwillingness was higher in females (19.9% [95% CI, 11.0%-24.8%]) compared with males (13.6% [95% CI, 8.0%-19.2%]), non-White individuals (21.7% [95% CI, 16.2%-27.3%]) than White individuals (14.8% [95% CI, 11.0%-18.5%]), and secondary or less (24.2% [95% CI, 18.8%-29.6%]) versus postsecondary education (15.9% [95% CI, 11.6%-20.2%]). Factors related to racial disparities, gender, education level, and age are discussed.

Public Preferences and Willingness to Pay for a COVID-19 Vaccine in Iran: A Discrete Choice Experiment

BACKGROUND AND OBJECTIVE

The coronavirus disease 2019 (COVID-19) pandemic is a major international threat and vaccination is the most robust strategy to terminate this crisis. It is helpful for policymakers to be aware of community preferences about vaccines. The present study aims to investigate the public's preferences and willingness to pay for the COVID-19 vaccine in Iran.

METHODS

This research is a cross-sectional study performed using a discrete choice experiment for a sample of the public population of several provinces of Iran in 2021. The samples were divided into two groups: one group expressed their preferences regarding the vaccine's attributes, and another group expressed their preferences regarding prioritizing individuals to get the vaccine. The discrete choice experiment design included five attributes including effectiveness, risk of severe complications, price, location of vaccine production, and duration of protection related to preferences for vaccine selection and six attributes including age, underlying diseases, employment in the healthcare sector, the rate of virus spread, the necessary job, and cost to the community related to preferences for prioritizing individuals to get the vaccine. A total of 715 individuals completed the questionnaire. The conditional logit regression model was used to analyze the discrete choice experiment data. Willingness to pay for each attribute was also calculated.

RESULTS

The willingness to pay for the COVID-19 vaccine with 90% (70%) efficacy, the risk of severe complications for 1 (5) person per one million people, imported (domestic) vaccine, and 24-month (12-month) duration of protection attributes was about US$71 (US$37). The preference for vaccination for respondents was enhanced by increasing the efficacy and the duration of vaccine protection and decreasing complications and costs. The likelihood of prioritizing individuals to get a vaccination was increased for a person with an underlying disease, employment in the healthcare sector, the necessary job for the community, the high potential for virus spread in the community, and the high cost of death to the community. The age variable was not statistically significant for prioritizing individuals to get the vaccine.

CONCLUSIONS

In the setting of the COVID-19 vaccination program, the public's preferences identified in this study should be considered. The obtained results provide useful information for policymakers to identify individual and social values for an appropriate vaccination strategy.