Are vaccination uptake and non-uptake influenced by our emotions? An experimental study on the role of emotional processes and compassion.

OBJECTIVE: This study examined the effects of emotional arousal, emotional competence, emotion regulation (ER), and compassion on COVID-19 and flu vaccination intentions (VI) among the French population. DESIGN: Data were collected online from October to December 2020. Altogether, 451 participants (Mage = 35.8, SD = 16.4) were allocated to four groups. High positive (n = 104) or negative (n = 103) emotional arousal were induced into two groups using pictures and music, and compared against a control group (flu group; n = 116) and a reference group (COVID-19 group; n = 114). All groups completed questionnaires on emotional arousal, ER, emotional competence, compassion, and VI. RESULTS: The findings indicated a significant effect of group on VI, h2=.023, 95% CI [-.002, .09]. The Group*Gender interaction on emotional arousal was non-significant, ηp2=.015, 95%CI [.000, .041]. However, emotional arousal was observed to have a significant main effect on VI, ηp2=.09, 95% CI [.043, .238]. The ER type*Emotional arousal*Gender interaction on ER use was trend, ηp2 = .002, 95% CI [.000, .005]. The emotional competence*ER type interaction on ER use was significant, ηp2 = .028, 95% CI [.011, .049]. Only experiential avoidance mediated the relationship between emotional arousal and VI, p < .018, 95% CI [.015, .18]. CONCLUSION: Emotional arousal impacts VI. High emotional competence only reduces the use of dysfunctional ER strategies.

Predicting the intention to receive the COVID-19 booster vaccine based on the health belief model.

COVID-19 vaccine boosters are recommended because the protection provided by previous doses eventually decreases, posing a threat to immunity. Some people, however, remain hesitant or unwilling to get vaccinated. The present study sought to investigate factors associated with the intention to receive the COVID-19 booster vaccine based on (1) the constructs of the Health Belief Model, and (2) trust in healthcare workers and science. A sample of 165 adults with two doses of the COVID-19 vaccine were recruited using convenience sampling. Data was collected using an online survey from November 2021 to January 2022. The survey included questions about participants' socio-demographic details, health beliefs, trust, history of COVID-19 vaccination, and the intention to receive a third dose of the COVID-19 vaccine. Ordinal logistic regression analysis showed that higher perceived benefits, severity, and trust in healthcare workers, and lower perceived barriers predicted higher willingness to get a third dose of the vaccine whereas perceived susceptibility and trust in science did not. Understanding the factors and health beliefs that underlie vaccine hesitancy are vital when developing effective interventions with the aim of increasing uptake of COVID-19 booster vaccines.

COVID-19 Vaccination and Predictive Factors in Immigrants to Europe: A Systematic Review and Meta-Analysis.

Vaccination plays a pivotal role in the control of infectious disease outbreaks. Hesitancy/refusal of the vaccine by immigrants poses a serious threat to their and society's health. We reviewed studies regarding COVID-19 vaccine uptake in Europe by first-generation immigrants. A systematic review (PROSPERO: CRD42023432142), conducted until 31 October 2023 using Web of Science, PubMed, and Scopus, identified 295 potential articles. Of these, 16 conducted on 2,009,820 immigrants in nine European countries met the eligibility criteria. Most studies were of medium/high quality according to the Newcastle-Ottawa Scale adapted for observational studies. Factors that affected the uptake or hesitancy/refusal to vaccinate, with particular regard to gender, age, and country of origin, were examined. The meta-analysis of eight studies revealed that the pooled estimated prevalence of COVID-19 vaccine uptake in first-generation immigrants was 71.3% (95% CI: 70.0-72.5%), corresponding to 13.3% less than the host country population (95% CI: 10.2-16.4%). Limitations of included studies and this review were deeply discussed, highlighting the need for further research on the effect of acculturation on second-generation immigrants. European governments need to ensure equal availability of COVID-19 and other health-saving vaccines to all immigrants in the future by overcoming cultural barriers, building trust in institutions, and improving communication.

Determinants of COVID-19 vaccination intention in Central and Eastern Europe: A cross-sectional study in Poland, Romania, and Slovenia.

BACKGROUND: Identifying predictors of vaccination intention is critical to developing appropriate programs and campaigns targeting groups reluctant to be vaccinated. This study aimed to identify the determinants of vaccination intention at the beginning of the COVID-19 pandemic in three Central and Eastern European (CEE) countries: Poland, Romania, and Slovenia. METHODS: In this cross-sectional study, a sample of unvaccinated 1723 Poles, Romanians, and Slovenians completed an online survey (April 2021). Questions included measures of vaccination intention, attitudes towards vaccines, conspiracy mindset, preference for a type of vaccine, and trust in information sources. RESULTS: The results showed that mistrust of vaccine benefits and concerns about commercial profiteering negatively predicted vaccination intention. Conversely, trust in information from medical professionals and scientists, official sources, and traditional media was positively related to vaccination intention, while trust in digital media was negatively related to vaccination intention. In addition, preference for mRNA vaccine type was a positive significant predictor of vaccination intention. The differences between countries are discussed. CONCLUSIONS: The study results deliver suggestions for developing appropriate vaccine uptake programs and campaigns that should consider presenting the positive outcomes of vaccines via official sources and traditional media based on scientific evidence and medical professionals' knowledge.

Determinants of HPV vaccine uptake intentions in Chinese clinical interns: an extended theory of planned behavior approach.

Background: This study aims to utilize the extended Theory of Planned Behavior (TPB) model to examine the intentions of clinical interns in China towards Human papillomaviruses (HPV) vaccination. It also fills a significant gap in the literature concerning vaccine acceptance in this specific population. Methods: This cross-sectional study was carried out with clinical interns in Shandong Province, China, with a total of 1,619 participants. Data were collected through self-reported questionnaires, including demographic characteristics, TPB variables, and HPV-related health knowledge. Hierarchical regression analysis was employed to identify key factors influencing vaccination intentions, and Structural Equation Modeling (SEM) was used to analyze the interrelationships between these factors. Results: This study initially identified key predictors affecting clinical interns' intentions to receive the HPV vaccine through hierarchical regression analysis. The preliminary model, which accounted for demographic factors, revealed foundational impacts of household income and HPV-related clinical experience on intentions. After integrating TPB variables-attitude, subjective norm, perceived behavioral control, and HPV-related health knowledge-the model's explanatory power was enhanced to 37.30%. SEM analysis focused on the interplay among TPB constructs and extended variables, confirming their significance in forming vaccination intentions, with subjective norm having the most substantial impact (ß = 0.375, p < 0.001). The extended TPB model explained over half of the variance in vaccination intentions, substantiating the hypotheses and revealing the psychological determinants behind clinical interns' decision-making for HPV vaccination. Conclusion: The extended TPB model from this study effectively explains the vaccination intentions among clinical interns for HPV, offering theoretical support for public health strategies and educational interventions targeting this group. These findings are of significant importance for public health practice and future health promotion strategies.

Psychosocial Factors Influencing Parents' Acceptance of COVID-19 Vaccination for Their Children: An Italian Cross-Sectional Study.

Vaccine hesitancy poses a significant threat to the health of individuals across all age groups, which has been exacerbated by the COVID-19 pandemic. In this cross-sectional study, an extension of the Theory of Planned Behavior (TPB) was applied to investigate psychosocial variables predicting intention to vaccinate children under 12 against COVID-19 in a sample of 420 Italian parents (Mean age = 40.4, SD = 5.9; Women = 78.1%). Hierarchical regression analysis revealed that, among the TPB variables, cognitive attitude, descriptive norms, and perceived behavioral control significantly predicted parents' vaccination intention. Furthermore, including trust in the institutions' ability to manage the vaccination campaign in the model significantly increased the explained variance in intention. These findings suggest that campaigns promoting childhood COVID-19 vaccination should not only emphasize the safety and effectiveness of vaccines for children but also focus on reducing barriers to vaccination. Additionally, attention should be given to enhancing the perception that this behavior is widespread among other parents, thus leveraging the power of social influence. Finally, and not less important, significant efforts should be directed toward building and reinforcing trust in the system of actors promoting and managing the COVID-19 vaccination campaign.

Human papillomavirus vaccination and contributing factors of vaccination intention among adolescents and young adults in China from a socio-ecological perspective: A cross-sectional study.

OBJECTIVES: Adolescents and young adults are the main target population for human papillomavirus (HPV). The study aimed to investigate school students' HPV vaccination intentions and explore the contributing factors from a socio-ecological perspective. DESIGN: A questionnaire survey was conducted in three secondary schools and three colleges in China. SAMPLE: A total of 1756 students aged 14-22 years participated in this study. Among the 1756 participants, 182 students have received the HPV vaccine. For the remaining 1574 students, we analyzed their HPV vaccination intentions and the influencing factors. MEASUREMENTS: Survey items for sociodemographics, knowledge and awareness of HPV, sexual intercourse and sexual knowledge, subjective socioeconomic status, self-efficacy, eHealth literacy, perceived social support from family, and the availability of HPV vaccine information were measured. RESULTS: Only 182 (10.4%) had received the HPV vaccine among the 1756 participants. Among the remaining 1574 students, the majority of the students (1403, 89.1%) were willing to receive the HPV vaccine. Binary logistic regression analysis showed that students who were female, had lower self-efficacy, scored higher on sexual knowledge, believed vaccination preventing related diseases, worried about side effects after vaccination, thought oneself at risk of contracting HPV, had higher family support, knew the availability of the HPV vaccine in Mainland China from healthcare institutions, and with family residence in rural areas were more willing to receive the HPV vaccine. CONCLUSIONS: Students had high HPV vaccination intentions while had low vaccination rate. Intrapersonal, interpersonal and institutional or community factors predicted HPV vaccination intention. Public health nurses in communities and schools could target the modifiable factors to promote students' HPV vaccine uptake.

Testing an extended theory of planned behaviour in predicting Covid-19 vaccination intention over the course of the pandemic: A three-wave repeated cross-sectional study.

Background: Mass vaccination against Covid-19 has been recognised as the most effective strategy for overcoming the pandemic emergency and remains crucial in the ongoing efforts to mitigate the impact of the virus. The present study aimed to test the efficacy of an extended Theory of Planned Behaviour (TPB) model in predicting vaccination intention in three different phases of the pandemic. Understanding how psychological drivers of vaccine acceptance may have changed throughout the pandemic is essential for informing public health strategies and addressing vaccine hesitancy, even in the current post-pandemic context. Methods: Using a repeated cross-sectional survey, we tested the hypothesised extended TPB model (intention, attitude, subjective norms, perceived behavioural control, anticipated affective reactions, risk perception, trust in science, trust in institutions and religiosity) across three independent samples: before (T1: November-December 2020; N = 657), during (T2: March-May 2021; N = 818), and after (T3: February-March 2022; N = 605) the start of the vaccination campaign in Italy. Results: Results indicated significant differences between the time points in all investigated variables, pointing to a general trend of improvement in vaccine acceptability levels at T2 compared to T1, and a worsening at T3 compared to the other two time points. Interestingly, net of these differences, a multi-group Structural Equation Modeling analysis supported the invariance, across time, of the structural relationships examined within the extended TPB. Conclusion: Findings demonstrated the efficacy of the TPB in predicting Covid-19 vaccination intention at different stages of the pandemic, suggesting that the model, in its extended version, represents a valuable framework for designing interventions aimed at promoting vaccine acceptance.

How to Improve People's Intentions Regarding COVID-19 Vaccination in China: A Randomized Controlled Trial.

BACKGROUND: The global COVID-19 pandemic has impaired the health and living conditions of millions of people. For governments to formulate policies promoting vaccination behavior, it is important to understand individuals' intentions to vaccinate. This study explores the effectiveness of a brief online intervention based on the Health Action Process Approach (HAPA) in improving individuals' COVID-19 vaccination intention, as well as considering the reasons for their unwillingness to get vaccinated. METHOD: A total of 1,258 participants were assessed using a questionnaire to determine their phase of vaccination intention (pre-intention, intention, and action). Subsequently, focused on the underlying factors in the pre-intention phase (i.e., task self-efficacy, outcome expectation, and risk perception), a 7-day randomized controlled HAPA intervention (n intervention = 57, n control = 49) was conducted online for individuals who were not willing to get vaccinated. The measurement points included pre- (T1), post- (T2), and 30-day follow-up (T3). RESULTS: The intervention may effectively improve participants' COVID-19 vaccination intentions; however, it had no impact on their planning and actions involved in taking the vaccine. CONCLUSIONS: This study provides relevant reference data for government stakeholders to use in developing public awareness campaigns and policies to encourage COVID-19 vaccination.

The Association between Message Framing and Intention to Vaccinate Predictive of Hepatitis A Vaccine Uptake.

As ongoing, sporadic outbreaks of hepatitis A virus (HAV) infections present public health challenges, it is critical to understand public perceptions about HAV, especially regarding vaccination. This study examines whether message framing changes the intention to vaccinate against HAV and self-reported vaccine behavior. Using a randomized controlled trial (N = 472) in February 2019 via Amazon Mechanical Turk, participants were randomized to one of four HAV vaccination message groups or a no-message control group. The message groups varied in their emphasis on the nature of outcomes (gain versus loss) and for whom (individual versus collective). The message frames were compared by intention to vaccinate, differences in message characteristics, and behavioral determinants. There was no difference in intention to vaccinate between gain- versus loss-framed messages (MD = 0.1, 95% CI = -0.1, 0.3) and individual- versus collective-framed messages (MD = 0.1, 95% CI = -0.1, 0.3). The intention to vaccinate against HAV in the no-message control group was very similar to that in the message groups. However, gain-framed messages were rated more positively in valence than loss-framed messages (MD = -0.5, 95% CI = -0.7, -0.3), which may be helpful for cultivating a positive public perception of HAV vaccination. The study also highlights the importance of comparing message frames to a no-message control in designing health communication messaging promoting HAV vaccination.

Tracking COVID-19 vaccination expectancies and vaccination refusal in the United States.

To identify factors that predict COVID-19 vaccination refusal and show how expectancies affect vaccination acceptance for non-vaccinated adults, we used a monthly repeated cross-sectional sample from June/2021 to October/2021 to collect data on vaccination behaviors and predictor variables for 2,116 US adults over 50 years of age. Selection bias modeling - which is required when data availability is a result of behavioral choice - predicts two outcomes: (1) no vaccination vs. vaccination for the entire sample and (2) the effects of expectancy indices predicting vaccination Refuser vs. vaccination Accepters for the unvaccinated group. Vaccine refusers were younger and less educated, endorsed common misconceptions about the COVID-19 epidemic, and were Black. Vaccination expectancies were related to vaccination refusal in the unvaccinated eligible group: negative expectancies increased vaccine refusal, while positive expectancies decreased it. We conclude that behavior-related expectancies (as opposed to more stable psychological traits) are important to identify because they are often modifiable and provide a point of intervention, not just for COVID-19 vaccination acceptance but also for other positive health behaviors.

Cultural tightness-looseness and normative social influence in eight Asian countries: Associations of individual and collective norms with vaccination intentions.

RATIONALE: Countries worldwide faced the same public health crisis that required promoting the same health behavior-vaccinations-during the COVID-19 pandemic. Thus, scholars have a unique opportunity to test behavioral change theories across countries with different cultural backgrounds. OBJECTIVE: Employing the extended theory of social normative behavior, this study examines the influence of individual and collective norms on COVID-19 vaccination intention across eight Asian countries. We examine how cultural tightness-looseness, defined as the degree of a culture's emphasis on norms and tolerance of deviant behavior, shapes normative social influence on COVID-19 vaccination intention. METHODS: We conducted a multicountry online survey (N = 2676) of unvaccinated individuals in China, Indonesia, Japan, Malaysia, Singapore, South Korea, Thailand, and Vietnam in May and June 2021, when COVID-19 vaccination mandates had not yet been implemented in those countries. We conducted hierarchical regression analyses with interaction terms for the total sample and then re-categorizied the eight countries as either "tight" (n = 1102) or "loose" (n = 1574) to examine three-way interactions between individual norms, collective norms, and cultural tightness-looseness. RESULTS: Perceived injunctive norms exerted the strongest impact of all normative factors on vaccination intention. Collective injunctive norms' influence depended on both perceived injunctive and descriptive norms, which was larger when norms were lower (vs. higher). The interactive pattern between perceived and collective norms was more pronounced in countries with greater cultural tightness. CONCLUSION: Our findings reveal nuanced patterns of how individual and collective social norms influence health behavioral decisions, depending on the degree of cultural tightness-looseness.

Awareness rate of PCV13 and influencing factors of vaccination intention among parents of infants and young children in Huangpu District , Shanghai / 公共卫生与预防医学

Objective To understand the awareness rate and willingness of parents of school-age infants and young children in Huangpu District, Shanghai to receive the 13 valent pneumococcal conjugate vaccine (PCV13) and its influencing factors, and to provide basic data for formulating community health education policies. Methods A stratified random sampling method was used to conduct a full coverage questionnaire survey on the PVC13 awareness rate and vaccination willingness of 1030 parents of infants and young children in 10 communities. Results A total of 1000 questionnaire surveys were completed, with an accurate response rate of 97.08%. The awareness rate of PCV13 was 85.50%, and the awareness rate of complications was less than 80%. The PCV13 vaccination rate was 55.60%. 38.74% of the reasons for not being vaccinated were concerned about vaccine side effects, and 32.21% were concerned about vaccine quality. The higher the education level of parents and the per capita annual income of the family, the higher the awareness rate of pneumococcal vaccine knowledge and the willingness to receive vaccination. Parents with registered residence in other places had low willingness to vaccinate PCV13. Conclusion The public has a higher awareness of PCV13 and a higher willingness to receive vaccination. It is necessary to strengthen the scientific popularization of complications of pneumococcal pneumonia and vaccine safety, strengthen vaccine safety supervision and disclosure of regulatory results, and strengthen PCV13 science popularization for parents of infants and young children with registered residence outside the city.

Factors associated with parental intention to vaccinate their child against influenza, Finland, February to March, 2022: a web-based survey.

BackgroundInfluenza vaccination for children aged 6 months to 6 years is included in the national vaccination programme in Finland. Although all vaccines in the programme are free of charge, national coverage of influenza vaccination among children under 3 years and 3-6 years during 2020/21 was 43% and 35% respectively, with regional differences.AimTo assess factors underlying parental vaccination intention in order to increase influenza vaccine uptake among children.MethodsWe conducted a web-based survey among parents (n = 17,844) of randomly selected eligible children (aged 6 months-6 years) in February-March 2022 in five Finnish municipalities from regions of high and low coverage. Logistic regressions were used to determine associations between vaccination intention and e.g. sociodemographic factors, attitudes and knowledge. Linkage to the national vaccination register was used to confirm realisation of vaccination intention after the study.ResultsParticipation rate was 13% (n = 2,322 parents). Influenza knowledge, trust in official information, responding parent's education level, adherence to the vaccination programme, number of children and changes in attitudes towards vaccination since COVID-19 were all associated with intention to vaccinate. Vaccination intention for children was 64%, and realised vaccination 51%.ConclusionDespite the low participation rate, both vaccinated and unvaccinated children were represented. Influenza vaccine uptake is not dependent on a single factor. Our results identified the need for open dialogue between parents and healthcare professionals, as the lack of vaccine being offered by healthcare professionals was the most reported reason for not vaccinating.

Psychological Factors of Vaccination Intent among Healthcare Providers, Parents, and Laypeople.

The interrelatedness of social-structural aspects and psychological features with vaccination intention provides the context to explore personal psychological features related to vaccination. Specifically, we focused on general decision making and vaccine-related dispositions, and their contribution to the intention to vaccinate, within post-pandemic circumstances, after the imposed possibility of choosing a vaccine brand. Our study aimed to map the function (promotive, protective, risk, vulnerability) of a set of personal psychological aspects in the intention to vaccinate among people holding different social roles regarding the vaccination. We surveyed three samples of people: healthcare providers (HPs), parents, and laypeople, within the post-pandemic context. Negative vaccine attitudes lower intention to vaccinate in all regression models (all ßs ranging from -0.128 to -0.983, all ps < 0.01). The main results indicate that, regardless of the sample/social role, there is a shared attitudinal core for positive vaccination intention. This core consists of [high] trust in large corporations, government, and healthcare systems, as well as perceived consensus on vaccine safety/efficacy and experience of freedom (protective factors), and [low] vaccination conspiracy beliefs, trust in social media, and choice overload (risk and vulnerability factors, respectively). There are no common promotive factors of intention to vaccinate: for parents, perceived consensus on vaccines, and trust in corporations and the healthcare system, play such roles; for HPs, the experience of freedom is obtained as a unique promotive factor. In contrast, for laypeople, no unique promotive factors were found. Our findings provide insights into the function of psychological factors of vaccination intention across different social roles, particularly healthcare providers, parents, and laypeople, and emphasize the need for tailored immunization interventions in the post-pandemic landscape.

Comparing factors influencing seasonal influenza vaccine acceptance and intentions among Chinese university students residing in China and UK: A cross-sectional study.

University students, who face an elevated risk of influenza due to close living quarters and frequent social interactions, often exhibit low vaccine uptake rates. This issue is particularly pronounced among Chinese students, who encounter unique barriers related to awareness and access, emphasizing the need for heightened attention to this problem within this demographic. This cross-sectional study conducted in May-June 2022 involved 1,006 participants (404 in the UK, 602 in Mainland China) and aimed to explore and compare the factors influencing influenza vaccine acceptance and intentions between Chinese university students residing in the UK (C-UK) and Mainland China (C-M). The study employed a self-administered questionnaire based on the Theoretical Domains Framework and Capability Opportunity Motivation-Behavior model. Results revealed that approximately 46.8% of C-UK students received the influenza vaccine in the past year, compared to 32.9% of C-M students. More than half in both groups (C-UK: 54.5%, C-M: 58.1%) had no plans for vaccination in the upcoming year. Knowledge, belief about consequences, and reinforcement significantly influenced previous vaccine acceptance and intention in both student groups. Barriers to vaccination behavior included insufficient knowledge about the influenza vaccine and its accessibility and the distance to the vaccine center. Enablers included the vaccination behavior of individuals within their social circles, motivation to protect others, and concerns regarding difficulties in accessing medical resources during the COVID-19 pandemic. The findings of this study offer valuable insights for evidence-based intervention design, providing evidence for healthcare professionals, policymakers, and educators working to enhance vaccination rates within this specific demographic.

To vaccinate or not to vaccinate? The interplay between pro- and against- vaccination reasons.

BACKGROUND: By mid 2023, European countries reached 75% of vaccine coverage for COVID-19 and although vaccination rates are quite high, many people are still hesitant. A plethora of studies have investigated factors associated with COVID-19 vaccine hesitancy, however, insufficient attention has been paid to the reasons why people get vaccinated against COVID-19. Our work aims to investigate the role of reasons in the decision to get vaccinated against COVID-19 in a representative sample of 1,689 adult Italians (March-April 2021) balanced in terms of age, gender, educational level and area of residence. METHODS: Through an online questionnaire, we asked participants to freely report up to three reasons for and against COVID-19 vaccination, and the weight each had in the decision to get vaccinated. We first investigated the role of emotional competence and COVID-19 risk perception in the generation of both reasons using regression models. Next, we studied the role that the different reasons had in the vaccination decision, considering both the intention to vaccinate (using a beta regression model) and the decision made by the participants who already had the opportunity to get vaccinated (using a logistic regression model). Finally, two different classification tree analyses were carried out to characterize profiles with a low or high willingness to get vaccinated or with a low or high probability to accept/book the vaccine. RESULTS: High emotional competence positively influences the generation of both reasons (ORs > 1.5), whereas high risk perception increases the generation of positive reasons (ORs > 1.4) while decreasing reasons against vaccination (OR = 0.64). As pro-reasons increase, vaccination acceptance increases, while the opposite happens as against-reasons increase (all p < 0.001). One strong reason in favor of vaccines is enough to unbalance the decision toward acceptance of vaccination, even when reasons against it are also present (p < 0.001). Protection and absence of distrust are the reasons that mostly drive willingness to be vaccinated and acceptance of an offered vaccine. CONCLUSIONS: Knowing the reasons that drive people's decision about such an important choice can suggest new communication insights to reduce possible negative reactions toward vaccination and people's hesitancy. Results are discussed considering results of other national and international studies.

Factors Associated with COVID-19 Vaccination Promptness after Eligibility in a North Carolina Longitudinal Cohort Study.

Many studies identified factors associated with vaccination intention and hesitancy, but factors associated with vaccination promptness and the effect of vaccination intention on vaccination promptness are unknown. This study identified factors associated with COVID-19 vaccination promptness and evaluated the role of vaccination intention on vaccination promptness in 1223 participants in a community-based longitudinal cohort study (June 2020 to December 2021). Participants answered questions regarding COVID-19 vaccination intention, vaccination status, and reasons for not receiving a vaccine. The association of baseline vaccine hesitancy with vaccination was assessed by the Kaplan-Meier survival analysis. Follow-up analyses tested the importance of other variables predicting vaccination using the Cox proportional hazards model. Older age was associated with shorter time to vaccination (HR = 1.76 [1.37-2.25] 85-year-old versus 65-year-old). Lower education levels (HR = 0.80 [0.69-0.92]), household incomes (HR = 0.84 [0.72-0.98]), and baseline vaccination intention of 'No' (HR = 0.16 [0.11-0.23]) were associated with longer times to vaccination. The most common reasons for not being vaccinated (N = 58) were vaccine safety concerns (n = 33), side effects (n = 28), and vaccine effectiveness (n = 25). Vaccination campaigns that target populations prone to hesitancy and address vaccine safety and effectiveness could be helpful in future vaccination rollouts.

Pathways to informed choices: The impact of freedom of choice and two-sided messages on psychological reactance and vaccination intentions among individuals who express concerns.

BACKGROUND: Reducing the spread of infectious diseases through vaccination faces the challenge of vaccine hesitancy: referring to questions, concerns and doubts arising when making a vaccine-related decision. A motivational state often arising within people exposed to health messages supporting informed decision making is psychological reactance, functioning as a driver to behavior opposed to the one recommended through the health message. Hence, there is a pressing need for communication strategies effective in counteracting reactance to health messages. METHODS: This study tested two communication strategies that can potentially reduce psychological reactance and ameliorate evaluations of the message and subsequent behavioral vaccination intentions in the context of COVID-19. These were: (1) explicitly reminding individuals of their freedom of choice (to either accept or refuse the vaccine) and (2) providing a two-sided message, including, apart from evidence-based information on the necessity of vaccines, a set of concerns, and questions (about the vaccines) which are refuted immediately. A total of 234 participants who indicated having concerns about the COVID-19 vaccine participated in a 2 (freedom of choice: no choice vs. choice) × 2 (message sidedness: one-sided vs. two-sided) between-subjects online experiment where they received an informational brochure about COVID-19 vaccination. RESULTS: The results show that emphasizing freedom of choice significantly increased perceived credibility of the message, perceived information utility, and ultimately, vaccination intentions. A decrease in psychological reactance mediated these effects. Message sidedness did only show a significant direct effect on perceived information utility. No interaction effect was found. CONCLUSION: These findings indicate the importance of freedom of choice in reducing psychological reactance, which in its turn can lead to an increase of positive message evaluations and vaccination intentions among individuals who express concerns. The opportunities of message sidedness as an efficacious vaccination communication strategy should be further investigated.

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.