The relative effects of determinants on Chinese adults’ decision for influenza vaccination choice: What is the effect of priming?

Motivators and Demotivators for COVID-19 Vaccination Based on Co-Occurrence Networks of Verbal Reasons for Vaccination Acceptance and Resistance: Repetitive Cross-Sectional Surveys and Network Analysis

BACKGROUND

Vaccine hesitancy is complex and multifaced. People may accept or reject a vaccine due to multiple and interconnected reasons, with some reasons being more salient in influencing vaccine acceptance or resistance and hence the most important intervention targets for addressing vaccine hesitancy.

OBJECTIVE

This study was aimed at assessing the connections and relative importance of motivators and demotivators for COVID-19 vaccination in Hong Kong based on co-occurrence networks of verbal reasons for vaccination acceptance and resistance from repetitive cross-sectional surveys.

METHODS

We conducted a series of random digit dialing telephone surveys to examine COVID-19 vaccine hesitancy among general Hong Kong adults between March 2021 and July 2022. A total of 5559 and 982 participants provided verbal reasons for accepting and resisting (rejecting or hesitating) a COVID-19 vaccine, respectively. The verbal reasons were initially coded to generate categories of motivators and demotivators for COVID-19 vaccination using a bottom-up approach. Then, all the generated codes were mapped onto the 5C model of vaccine hesitancy. On the basis of the identified reasons, we conducted a co-occurrence network analysis to understand how motivating or demotivating reasons were comentioned to shape people's vaccination decisions. Each reason's eigenvector centrality was calculated to quantify their relative importance in the network. Analyses were also stratified by age group.

RESULTS

The co-occurrence network analysis found that the perception of personal risk to the disease (egicentrality=0.80) and the social responsibility to protect others (egicentrality=0.58) were the most important comentioned reasons that motivate COVID-19 vaccination, while lack of vaccine confidence (egicentrality=0.89) and complacency (perceived low disease risk and low importance of vaccination; egicentrality=0.45) were the most important comentioned reasons that demotivate COVID-19 vaccination. For older people aged ≥65 years, protecting others was a more important motivator (egicentrality=0.57), while the concern about poor health status was a more important demotivator (egicentrality=0.42); for young people aged 18 to 24 years, recovering life normalcy (egicentrality=0.20) and vaccine mandates (egicentrality=0.26) were the more important motivators, while complacency (egicentrality=0.77) was a more important demotivator for COVID-19 vaccination uptake.

CONCLUSIONS

When disease risk is perceived to be high, promoting social responsibility to protect others is more important for boosting vaccination acceptance. However, when disease risk is perceived to be low and complacency exists, fostering confidence in vaccines to address vaccine hesitancy becomes more important. Interventions for promoting vaccination acceptance and reducing vaccine hesitancy should be tailored by age.

Parental preference for influenza vaccine for children in China: a discrete choice experiment

OBJECTIVES

To investigate what factors affect parents' influenza vaccination preference for their children and whether there exists preference heterogeneity among respondents in China.

DESIGN

Cross-sectional study. A discrete choice experiment was conducted. Five attributes were identified based on literature review and qualitative interviews, including protection rate, duration of vaccine-induced protection, risk of serious side effects, location of manufacturer and out-of-pocket cost.

SETTING

Multistage sampling design was used. According to geographical location and the level of economic development, 10 provinces in China were selected, and the survey was conducted at community healthcare centres or stations.

PARTICIPANTS

Parents with at least one child aged between 6 months and 5 years old were recruited and the survey was conducted via a face-to-face interview in 2019. In total, 600 parents completed the survey, and 449 who passed the internal consistency test were included in the main analysis.

MAIN OUTCOMES AND MEASURES

A mixed logit model was used to estimate factors affecting parents' preference to vaccinate their children. In addition, sociodemographic characteristics were included to explore the preference heterogeneity.

RESULTS

In general, respondents preferred to vaccinate their children. All attributes were statistically significant and among them, the risk of severe side effects was the most important attribute, followed by the protection rate and duration of vaccine-induced protection. Contrary to our initial expectation, respondents have a stronger preference for the domestic than the imported vaccine. Some preference heterogeneity among parents was also found and in particular, parents who were older, or highly educated placed a higher weight on a higher protection rate.

CONCLUSION

Vaccination safety and vaccine effectiveness are the two most important characteristics that influenced parents' decision to vaccinate against influenza for their children in China. Results from this study will facilitate future policy implementations to improve vaccination uptake rates.

Parental Preferences of Influenza Vaccination for Children in China: A National Survey with a Discrete Choice Experiment

The influenza vaccination coverage among children is low in China. We aimed to conduct a nationwide survey to quantify parental preferences and willingness to pay (WTP) for influenza vaccination for their children. Parents with children aged six months to 18 years from six provinces in China were investigated by a discrete choice experiment regarding six influenza vaccination attributes. Mixed logit models were used to estimate the relative importance of vaccine attributes and parents’ WTP. Interaction analysis and subgroup analysis were conducted to explore preference heterogeneity. A total of 1206 parents were included in the analysis. Parents reported vaccine effectiveness as the most important vaccine attribute. The mode of vaccine administration had no significant impact on parents’ preferences. Parents aged over 30 years with higher education or income levels were more likely to prefer no influenza vaccination for their children. The largest marginal WTP (CNY 802.57) for vaccination and the largest increase in vaccine uptake (41.85%) occurred with improved vaccine effectiveness from 30% to 80%. Parents from central regions or mid-latitude areas had a relatively lower WTP than those from other regions. No significant difference in the relative importance of vaccine attributes were observed among parents from various regions of China.

Priming with social benefit information of vaccination to increase acceptance of COVID-19 vaccines

Vaccine hesitancy can be heightened due to increasing negative reports about vaccines. Emphasizing the social benefits of vaccination may shift individual attention from individual to social benefit of vaccination and hence promote prosocial vaccination. In six rounds of a population-based survey conducted over one major community epidemic of coronavirus disease 2019 (COVID-19) in Hong Kong from June to November 2020, we manipulated the question asking about acceptance of a COVID-19 vaccine with or without emphasizing the social benefit of vaccination against COVID-19 (prosocial priming) and monitored the changes of vaccine confidence by news media sentiment on vaccines. Population-weighted percentages of accepting COVID-19 vaccines by priming condition and vaccine confidence were compared across survey rounds. Logit regression models assessed the main effect of prosocial priming and the modification effects of vaccine confidence and perceived personal risk from COVID-19 on acceptance of COVID-19 vaccines. We found that prosocial priming significantly increased acceptance of COVID-19 vaccines across all survey rounds except for Round 3 when incidence of COVID-19 reached a peak. Vaccine confidence significantly declined in Round 6 when news media sentiment on vaccines became predominantly negative. The effect of prosocial priming on promoting vaccine acceptance was significantly greater in participants with low vaccine confidence and those perceiving the severity of COVID-19 to be mild/very mild. Our study suggests that packaging vaccination against COVID-19 as a prosocial behaviour can help overcome low vaccine confidence and promote prosocial vaccination particularly when disease incidence temporarily declines and the public perceive low severity of COVID-19.

Immediate and informative feedback during a pandemic: Using stated preference analysis to predict vaccine uptake rates

In response to an emerging pandemic, there is urgent need for information regarding individual evaluation of risk and preferences toward mitigation strategies such as vaccinations. However, with social distancing policies and financial stress during an outbreak, traditional robust survey methodologies of face-to-face, probabilistic sampling, may not be feasible to deploy quickly, especially in developing countries. We recommend a protocol that calls for a sensitive survey design, acceptance of a web-based approach and adjustments for uncertainty of respondents, to deliver urgently needed information to policymakers as the public health crisis unfolds, rather than in its aftermath. This information is critical to tailor comprehensive vaccination campaigns that reach critical immunity thresholds. We apply our recommendations in a regional study of 16 Latin American countries in the month following index cases of COVID-19. We use a split-sample, contingent valuation approach to evaluate the effects of cost, duration of immunity and effectiveness of the vaccine. Our results show that cost and duration of immunity are significant factors in the decision to vaccinate, while the degree of effectiveness is insignificant, unless the vaccine is 100% effective. Income as well as perceived risk and severity of the virus are important determinants also.

Vaccine preferences driving vaccine-decision making of different target groups: a systematic review of choice-based experiments

BACKGROUND

Choice-based experiments have been increasingly used to elicit preferences for vaccines and vaccination programs. This study aims to systematically identify and examine choice-based experiments assessing (differences in) vaccine preferences of vaccinees, representatives and health advisors.

METHODS

Five electronic databases were searched on choice-based conjoint analysis studies or discrete choice experiments capturing vaccine preferences of children, adolescents, parents, adults and healthcare professionals for attributes of vaccines or vaccine settings up to September 2020. Data was extracted using a standardized form covering all important aspects of choice experiments. A quality assessment was used to assess the validity of studies. Attributes were categorized into outcome, process, cost and other. The importance of attributes was assessed by the frequency of reporting and statistical significance. Results were compared between high-quality studies and lower-quality studies.

RESULTS

A total of 42 studies were included, with the majority conducted in high-income countries after 2010 (resp. n = 34 and n = 37). Preferences of representatives were studied in nearly half of the studies (47.6%), followed by vaccinees (35.7%) and health advisors (9.5%). Sixteen high-quality studies passed the quality assessment. Outcome- and cost- related attributes such as vaccine effectiveness, vaccine risk, cost and protection duration were most often statistically significant across both target groups, with vaccine effectiveness being the most important. Risks associated with vaccination, such as side effects, were more often statistically significant in studies targeting vaccinees, while cost-related attributes were more often statistically significant in studies of representatives. Process-related attributes such as vaccine accessibility and time were least important across both target groups.

CONCLUSION

To our knowledge, this is the first systematic review in which vaccine preferences of different target groups were assessed and compared. The same attributes were most important for vaccine decisions of vaccinees and representatives, with only minor differences in level of evidence for vaccine risk and cost. Future research on vaccine preferences of health advisors and/or among target groups in low-resource settings would give insight into the generalizability of current findings.

Preference of influenza vaccination among the elderly population in Shaanxi province, China

The influenza vaccination uptake rate is low in China. In the current study, we aimed to explore the preferences of influenza vaccination among the Chinese elderly. A discrete choice experiment design was performed to assess their preferences toward five influenza vaccination attributes, including vaccine effectiveness, duration of protection, severe adverse effects, vaccination cost, and vaccination recommendation source. A total of 144 participants aged over 60 years from three cities of Shaanxi province in China were surveyed. A mixed logit model was employed to analyze the data. The elderly population were found to prefer influenza vaccination with a longer duration of protection, followed by lower severe adverse effects, higher vaccine effectiveness, and recommended by healthcare providers. The vaccination cost was the least important attribute. The most considerable marginal willingness to pay for vaccination (CNY220.90) and the highest vaccination choice probability (83.70%) occurred when the duration of protection extended from 3 to 12 months. The present study's findings would inform decision-makers on implementing appropriate interventions for the increase of influenza vaccination coverage among the elderly in China.

Parental Vaccine Preferences for Their Children in China: A Discrete Choice Experiment

Vaccination is one of the most cost-effective health investments to prevent and control communicable diseases. Improving the vaccination rate of children is important for all nations, and for China in particular since the advent of the two-child policy. This study aims to elicit the stated preference of parents for vaccination following recent vaccine-related incidents in China. Potential preference heterogeneity was also explored among respondents. Methods: A discrete choice experiment was developed to elicit parental preferences regarding the key features of vaccines in 2019. The study recruited a national sample of parents from 10 provinces who had at least one child aged between 6 months and 5 years old. A conditional logit model and a mixed logit model were used to estimate parental preference. Results: A total of 598 parents completed the questionnaire; among them, 428 respondents who passed the rational tests were analyzed. All attributes except for the severity of diseases prevented by vaccines were statistically significant. The risk of severe side effects and protection rates were the two most important factors explaining parents’ decisions about vaccination. The results of the mixed logit model with interactions indicate that fathers or rural parents were more likely to vaccinate their children, and children whose health was not good were also more likely to be vaccinated. In addition, parents who were not more than 30 years old had a stronger preference for efficiency, and well-educated parents preferred imported vaccines with the lowest risk of severe side effects. Conclusion: When deciding about vaccinations for their children, parents in China are mostly driven by vaccination safety and vaccine effectiveness and were not affected by the severity of diseases. These findings will be useful for increasing the acceptability of vaccination in China.

Public preference for COVID-19 vaccines in China: A discrete choice experiment

Background

As the coronavirus disease 2019 (COVID‐19) pandemic is sweeping across the globe, there is an urgent need to develop effective vaccines as the most powerful strategy to end the pandemic. This study aimed to examine how factors related to vaccine characteristics, their social normative influence and convenience of vaccination can affect the public's preference for the uptake of the COVID‐19 vaccine in China.

Methods

An online discrete choice experiment (DCE) survey was administered to a sample of China's general population. Participants were asked to make a series of hypothetical choices and estimate their preference for different attributes of the vaccine. A mixed logit regression model was used to analyse the DCE data. Willingness to pay for each attribute was also calculated.

Results

Data of 1236 participants who provided valid responses were included in the analysis. There was strong public preference for high effectiveness of the vaccine, followed by long protective duration, very few adverse events and being manufactured overseas. Price was the least important attribute affecting the public preference in selecting the COVID‐19 vaccine.

Conclusions

The strong public preferences detected in this study should be considered when developing COVID‐19 vaccination programme in China. The results provide useful information for policymakers to identify the individual and social values for a good vaccination strategy.

Patient or Public Contribution

The design of the experimental choices was fully based on interviews and focus group discussions participated by 26 Chinese people with diverse socio‐economic backgrounds. Without their participation, the study would not be possible.

Behavioral Differences in the Preference for Hepatitis B Virus Vaccination: A Discrete Choice Experiment

Understanding behavioral factors differences in the preferences for vaccinations can improve predictions of vaccine uptake rates and identify effective policy interventions to increase the demand for vaccinations. In this study, 353 adults in Shandong province in China were interviewed about their preferences for hepatitis B virus (HBV) vaccination. A discrete choice experiment (DCE) was employed to analyze the preference for HBV vaccinations, and a mixed logit model was used to estimate respondent preferences for vaccination attributes included in the DCE. While the protection rate against hepatitis B (HB), duration of protection, risk of side-effects, and vaccination cost were shown to influence adults’ preferences for HBV vaccination, adults valued “99% hepatitis B protection” above other attributes, followed by “20 years’ protection duration” and “1 in 150,000 risk of side-effects”. Individuals with lower time discount rates, non-overconfidence, or higher risk aversion were more likely to choose a vaccine. Lower risk aversion individuals showed a higher preference for lower risk of side-effects. Lower time discount rate individuals showed a higher preference for longer protection duration. Non-overconfidence individuals showed a higher preference for higher hepatitis B protection and cost. Interventions should be targeted to the behavioral determinants impeding vaccination.

What influenza vaccination programmes are preferred by healthcare personnel? A discrete choice experiment

OBJECTIVES

This study examined the relative importance of factors relating to vaccine characteristics, social normative influence and convenience in access to vaccine for determining decision making for seasonal influenza vaccination (SIV) among healthcare personnel (HCP), aiming to optimize existing influenza vaccination programmes for HCP.

METHODS

A discrete choice experiment (DCE) was conducted in HCP working in public hospitals in Hong Kong. The DCE was designed to examine the relative importance of vaccine characteristics (vaccine efficacy and safety), social normative influence reflected by the proportion of HCP colleagues intending to take SIV, and convenience in access to vaccine indicated by vaccination programme duration, vaccination location, vaccination arrangement procedure and service hours in determining influenza vaccination choice among HCP. Mixed logit regression modelling was conducted to examine the preference weight (β) of factors included in the DCE for determining vaccination choice.

RESULTS

Vaccination probability increased with increase in vaccine efficacy (β = 0.02 for per 1% increase), vaccination location changing from "designated staff clinic" to "mobile station" (β = 0.37), vaccination arrangement procedure changing from "by appointment" to "by walk-in" (β = 0.99), but decreased with the increase in probability of mild reactions to vaccination (β = -0.05 for per 1% increase).

CONCLUSION

Vaccine safety was judged to be more important than vaccine efficacy for determining vaccination choice. Arranging vaccination service by walk-in and implementing mobile vaccination station should be considered in future SIV programmes to compensate for the effect of perceived low vaccination efficacy and concerns about vaccine safety to promote SIV uptake among HCP.

Acceptance of and preference for COVID-19 vaccination in healthcare workers: a comparative analysis and discrete choice experiment.. [PMID: 0 DOI: 10.1101/2020.04.09.20060103]

Background

A major obstacle to successful coronavirus disease (COVID-19) vaccine rollout is vaccine hesitancy. Acceptance of and preferences for COVID-19 vaccination among healthcare workers (HCWs) is critical, because they are a key target group for vaccination programs, and they are also highly influential to vaccine uptake in the wider population. This study sought to comparatively determine the acceptance of and preference for COVID-19 vaccination among HCWs and the general population.

Methods

An Internet-based, region-stratified discrete-choice experiment was conducted among 352 HCWs and 189 general population respondents recruited in March 2020 from 26 Chinese provinces. We accessed knowledge of disease, attitude towards and acceptance of COVID-19 vaccination. Several attributes (related to COVID-19 disease, COVID-19 vaccination and one social acceptance) were identified as key determinants of vaccine acceptance.

Results

HCWs had a more in-depth understanding of COVID-19 and showed a higher willingness to accept COVID-19 vaccines with lower effectiveness and/or more severe adverse effects compared to the general population. 76.4% of HCWs (vs 72.5% of the general population) expressed willingness to receive vaccination (χ2=2.904, p=0.234). High levels of willingness to accept influenza (65.3%) and pneumococcal (55.7%) vaccination were also seen in HCWs. Future COVID-19 disease incidence (OR: 4.367, 95% CI 3.721–5.126), decisions about vaccination among social contacts of respondents (OR 0.398, 95% CI 0.339–0.467), and infection risk >30% (OR 2.706, 95% CI 1.776–2.425) significantly increased the probability of vaccination acceptance in HCWs.

Conclusion

Multi-component interventions to address the key determinants of hesitancy in both HCWs and in the general population should be considered for COVID-19 vaccination programs.

The influence of a community intervention on influenza vaccination knowledge and behavior among diabetic patients

BACKGROUND

This study was conducted to evaluate the impact of a comprehensive community intervention on cognition and inoculation behaviors of diabetic patients immunized with influenza vaccine.

METHODS

A total of 1538 diabetic patients aged 35 years and above for outpatient visits and follow-up treatments were selected from six community health service centers (three for the experimental group, and the other three for the control group) in Chaoyang District, Beijing. Comprehensive interventions applied to the experimental group include patient intervention and community climate interventions. We compared the total awareness of influenza vaccine knowledge and influenza vaccination rates between the two groups before and after the intervention.

RESULTS

Before the intervention, the total awareness rate of influenza vaccine in the experimental group and the control group was similar (50.6 and 50.2%, respectively. P = 0.171). After the intervention, the awareness rate of influenza vaccine in the experimental group and the control group increased. The amplitude of the increase was similar (70.3 and 70.1%, respectively. P = 0.822,). Before the intervention, there was no significant difference in the influenza vaccination rate between the experimental group and the control group (29.0 and 26.8%, respectively. P = 0.334). After the intervention, the vaccination rate of the experimental group was higher than that of the control group. The difference was statistically significant (The vaccination rate 45.8 and 27.4% for the experimental group and the control group, respectively. P < 0.001).

CONCLUSION

Comprehensive community interventions had a positive effect on vaccination in diabetic patients.

TRIAL REGISTRATION

ChiCTR1900025194, registered in Aug,16th, 2019. Retrospectively registered.