No Such Thing as a Free-Rider? Understanding Drivers of Childhood and Adult Vaccination through a Multicountry Discrete Choice Experiment

Parental preferences for rotavirus vaccination for their children under 5 years old in China: A discrete choice experiment

Rotavirus vaccination is the most effective means to prevent rotavirus gastroenteritis, but its coverage in China is not ideal. We aimed to explore parental preferences for rotavirus vaccination for their children under 5years old to improve vaccination coverage. A Discrete Choice Experiment was conducted online on 415 parents with at least one child under 5years old in 3 cities. Five attributes including vaccine effectiveness, protection duration, risk of mild side-effects, out-of-pocket costs, and time required for vaccination were identified. Each attribute was set at three levels. Mixed-logit models were used to measure parental preferences and the relative importance of vaccine attributes. The optimal vaccination strategy was also explored. 359 samples were included in the analysis. The impacts of the vaccine attribute levels on vaccine choice were all statistically significant (p < .01), except for 1-hour vaccination time. The risk of mild side-effects was the most important factor influencing vaccination. The time required for vaccination was the least important attribute. The largest increase in vaccination uptake (74.45%) occurred with decreased the vaccine risk of mild side-effects from 1/10 to 1/50. The predicted vaccination uptake of the optimal vaccination scenario was 91.79%. When deciding about vaccination, parents preferred the rotavirus vaccination with lower risk of mild side-effects, higher effectiveness, longer protection duration, 2-hour vaccination time and lower cost. The authorities should support enterprises to develop vaccines with lower side-effects, higher effectiveness and longer protection duration in the future. We call for appropriate government subsidies for the rotavirus vaccine.

A taxonomy of anti-vaccination arguments from a systematic literature review and text modelling

The proliferation of anti-vaccination arguments is a threat to the success of many immunization programmes. Effective rebuttal of contrarian arguments requires an approach that goes beyond addressing flaws in the arguments, by also considering the attitude roots-that is, the underlying psychological attributes driving a person's belief-of opposition to vaccines. Here, through a pre-registered systematic literature review of 152 scientific articles and thematic analysis of anti-vaccination arguments, we developed a hierarchical taxonomy that relates common arguments and themes to 11 attitude roots that explain why an individual might express opposition to vaccination. We further validated our taxonomy on coronavirus disease 2019 anti-vaccination misinformation, through a combination of human coding and machine learning using natural language processing algorithms. Overall, the taxonomy serves as a theoretical framework to link expressed opposition of vaccines to their underlying psychological processes. This enables future work to develop targeted rebuttals and other interventions that address the underlying motives of anti-vaccination arguments.

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.

Effect of ontological insecurity on vaccination behavior against COVID-19: a hospital-based cross-sectional study

OBJECTIVE

Coronavirus disease 2019 (COVID-19) has brought great uncertainty to our society and it may have disrupted people's ontological security. Consequently, this hospital-based study concerns the impact of ontological insecurity on vaccination behavior against COVID-19.

STUDY DESIGN

This cross-sectional study was conducted among hospital inpatients.

METHODS

A questionnaire survey addressing inpatient ontological insecurity and vaccination behavior against COVID-19 was administered in Taizhou, China. A total of 1223 questionnaires were collected; specifically, 1185 of them were credible, for a validity rate of 96.9%.

RESULTS

The score of ontological insecurity was 13.27 ± 7.84, which was higher in participants who did not recommend vaccination for others than those who did (12.95 ± 8.25 vs 14.00 ± 6.78, P = 0.022). There was no difference between the vaccinated and unvaccinated groups (13.22 ± 7.96 vs 13.35 ± 7.67, P = 0.779). Lower ontological insecurity (odds ratio [OR] = 1.40, 95% confidence interval [CI]: 1.08-1.81) and being inoculated with COVID-19 vaccines (OR = 2.17, 95% CI: 1.67-2.82) were significantly associated with recommendation of COVID-19 vaccines to others after adjusting for sex, age, education, and occupation. Associations between low ontological insecurity and recommendations for COVID-19 vaccines were observed in men, adults aged 18-59 years, non-farmers, and vaccine recipients.

CONCLUSIONS

This study suggests that the ontological insecurity of participants affects their behavior of recommending the COVID-19 vaccination to others rather than getting vaccinated themselves. This promotion of vaccination can be considered from the perspective of improving ontological security in China.

Individual factors influencing COVID-19 vaccine acceptance in between and during pandemic waves (July-December 2020)

Background

A year after the start of the COVID-19 outbreak, the global rollout of vaccines gives us hope of ending the pandemic. Lack of vaccine confidence, however, poses a threat to vaccination campaigns. This study aims at identifying individuals’ characteristics that explain vaccine willingness in Flanders (Belgium), while also describing trends over time (July–December 2020).

Methods

The analysis included data of 10 survey waves of the Great Corona Survey, a large-scale online survey that was open to the general public and had 17,722–32,219 respondents per wave. Uni- and multivariable general additive models were fitted to associate vaccine willingness with socio-demographic and behavioral variables, while correcting for temporal and geographical variability.

Results

We found 84.2% of the respondents willing to be vaccinated, i.e., respondents answering that they were definitely (61.2%) or probably (23.0%) willing to get a COVID-19 vaccine, while 9.8% indicated maybe, 3.9% probably not and 2.2% definitely not. In Flanders, vaccine willingness was highest in July 2020 (90.0%), decreased over the summer period to 80.2% and started to increase again from late September, reaching 85.9% at the end of December 2020. Vaccine willingness was significantly associated with respondents’ characteristics: previous survey participation, age, gender, province, educational attainment, household size, financial situation, employment sector, underlying medical conditions, mental well-being, government trust, knowing someone with severe COVID-19 symptoms and compliance with restrictive measures. These variables could explain much, but not all, variation in vaccine willingness.

Conclusions

Both the timing and location of data collection influence vaccine willingness results, emphasizing that comparing data from different regions, countries and/or timepoints should be done with caution. To maximize COVID-19 vaccination coverage, vaccination campaigns should focus on (a combination of) subpopulations: aged 31–50, females, low educational attainment, large households, difficult financial situation, low mental well-being and labourers, unemployed and self-employed citizens.