Preferential differences in vaccination decision-making for oneself or one's child in The Netherlands: a discrete choice experiment

A latent class analysis of factors influencing preferences for infant respiratory syncytial virus (RSV) preventives among pregnant people in the United States

A maternal vaccine and long-acting monoclonal antibody (mAb) were recently approved to protect infants against respiratory syncytial virus (RSV). We identified subgroups of pregnant people with different preferences for RSV preventives and respondent characteristics associated with subgroup membership. An online survey, including a discrete choice experiment (DCE), was conducted among US pregnant people. RSV preventive attributes included effectiveness, duration of protection during RSV season, injection recipient/timing, preventive type (vaccine or mAb), and type of visit required to receive injection. In DCE choice tasks, pregnant people selected between two hypothetical preventive profiles with varying attribute-levels and a no-preventive option. Logistic regression, including latent class analysis (LCA), was used to analyze the data. Of 992 pregnant people (mean age: 30.0 years), 60.3% were expecting their second/later birth. LCA identified three preference subgroups: 'Effectiveness' (preventive choice mostly driven by increases in effectiveness; 51.4% class membership probability), 'Season' (preventive choice mostly driven by improvement in duration of protection during the RSV season; 39.2% class membership probability), and 'No Preventive' (frequently chose no-preventive option; 9.4% class membership probability). 'Effectiveness' and 'Season' preferred maternal vaccine over mAb; mAb was preferred by 'No Preventive.' Perceiving RSV as serious for infants, higher health literacy, and lower household income were associated with 'Effectiveness.' Perceiving RSV as serious for pregnant people was associated with 'Season.' Perceiving RSV to not be serious for pregnant people and not being employed were associated with 'No Preventive.' Subgroups of pregnant people vary in preferences for RSV preventives. Most pregnant people preferred a maternal vaccine, although some may be more willing to accept alternative preventive options.

Nationwide Discrete Choice Experiment on Chinese Guardians' Preferences for HPV Vaccination for Mothers and Daughters

Background: HPV vaccination is the key measure to prevent cervical cancer, but uptake in China lags behind global targets. Understanding Chinese guardians' preferences is key to improving vaccine acceptance and coverage. Methods: A nationwide online discrete choice experiment survey was conducted among 4933 Chinese guardians across seven provinces in 2022 to quantify preferences and willingness to pay. Attributes included effectiveness, safety, duration, valency, location, and out-of-pocket cost. Results: Out of the 4933 guardians who participated in the study, 4179 (84.72%) were mothers. More than 60% of the guardians belonged to the age group of 35-44 years. Additionally, over half of the respondents (53.15%) had daughters between the ages of 9 and 14 years. Respondents were open to accepting the HPV vaccine with 95% efficacy and exceptional safety. Guardians expressed a preference for longer protection duration (specifically 15 years (βa = 0.340, 95% CI: 0.31, 0.37)) and higher vaccine valency. As for willingness to pay, the respondents placed the highest value on vaccine efficacy, being willing to shell out more than USD 1100 for 95% protection as compared to 50%. Furthermore, very good safety commanded a premium of over USD 800 when compared to average safety. When it comes to willingness to uptake, a vaccine with 95% efficacy led to a more than 35% increase in acceptance as compared to one with 50% efficacy. Similarly, exceptional safety resulted in an increased willingness to uptake of over 25% when compared to average safety. Conclusions: The DCE highlighted effectiveness, safety, and durability as critical drivers of HPV vaccine acceptance, but substantial barriers persist regarding adolescent female coverage in China.

Maternal skepticism regarding children's vaccination in Jordan: Investigating the knowledge, attitude, and adherence

Vaccination is critical to every responsible healthcare system, yielding several health and economic benefits. However, skepticism is a major challenge to vaccination adherence among parents globally. Mothers are primary decision-makers on children's vaccination; therefore, this study aims to assess maternal knowledge, attitudes, and adherence to children's routine vaccination in Jordan, identify the main sources of related information, and explore the awareness and hesitancy related to elective vaccination, which is not incorporated into the national vaccination program (e.g., varicella, flu, meningitis, and meningococcal vaccines). A descriptive, cross-sectional design was conducted to collect data from 533 Jordanian mothers between August and November 2023. Participant mothers completed an online self-administered questionnaire comprising demographics, knowledge, attitudes, and adherence to children's vaccination. The surveyed mothers in general exhibited high levels of knowledge, attitudes, and adherence concerning children's vaccination and a relatively moderate level of adherence concerning elective vaccines. The mothers' perspectives of reluctance towards elective vaccines were explored. The primary healthcare center and physicians were the most prevalent sources of mothers' vaccine-related information. Future efforts should implement tailored health education campaigns that address specific knowledge gaps, such as misconceptions about contraindications and side effects, promote awareness about elective vaccines, and engage healthcare providers to facilitate informed decision-making among Jordanian mothers and improve children's vaccination coverage.

Perceptions and Acceptance of a Prophylactic Vaccine for Human Immunodeficiency Virus (HIV): A Qualitative Study

BACKGROUND

Despite advances in human immunodeficiency virus (HIV) prevention methods, such as the advent of pre-exposure prophylaxis (PrEP), the number of people with newly acquired HIV remains high, particularly in at-risk groups. A prophylactic HIV vaccine could contribute to reduced disease prevalence and future transmission and address limitations of existing options, such as suboptimal long-term adherence to PrEPs.

METHODS

This qualitative study aimed to capture perceptions towards and acceptance of prophylactic HIV vaccination in three adult populations in the United States: the general population, 'at-risk' individuals (e.g. men who have sex with men, transgender individuals, gender-nonconforming individuals, and individuals in a sexual relationship with a person living with HIV), and parents/caregivers of children aged 9-17 years. Interviews were conducted with 55 participants to explore key drivers and barriers to HIV vaccine uptake, and a conceptual model was developed.

RESULTS

The sample was diverse; participants were 51% female, aged 20-57 years (mean 37 years), 33% with high school diploma as highest education level, and identified as White (42%), Black or African American (35%), of Hispanic, Latino, or Spanish origin (22%), or other races/ethnicities (8%) [groupings are not mutually exclusive]. Perceptions were influenced by individual, interpersonal, community, institutional, and structural factors. Overall, 98% of participants thought vaccination would be beneficial in preventing HIV. Key considerations/barriers included perceived susceptibility, i.e. whether participants felt there was a risk of contracting HIV (discussed by 90%); the clinical profile of the vaccine (e.g. the adverse effect profile [98%], and vaccine efficacy [85%], cost [73%] and administration schedule [88%]); and concerns around potential vaccine-induced seropositivity (VISP; 62%). Stigma was not found to be an important barrier, with a general view that vaccination status was personal. Participants in the 'at-risk' group were the most likely to accept an HIV vaccine (70%). Unique concerns in the subgroups included how a potential vaccine's clinical profile compared with PrEP, voiced by those receiving/considering PrEP, and considerations of children's views on the topic, voiced by parents/caregivers.

CONCLUSIONS

Understanding these factors could help develop HIV vaccine research strategies and contribute toward public health messaging to support future HIV vaccination programs.

Healthcare Providers' and Pregnant People's Preferences for a Preventive to Protect Infants from Serious Illness Due to Respiratory Syncytial Virus

We assessed the impact of respiratory syncytial virus (RSV) preventive characteristics on the intentions of pregnant people and healthcare providers (HCPs) to protect infants with a maternal vaccine or monoclonal antibodies (mAbs). Pregnant people and HCPs who treated pregnant people and/or infants were recruited via convenience sample from a general research panel to complete a cross-sectional, web-based survey, including a discrete choice experiment (DCE) wherein respondents chose between hypothetical RSV preventive profiles varying on five attributes (effectiveness, preventive type [maternal vaccine vs. mAb], injection recipient/timing, type of medical visit required to receive the injection, and duration of protection during RSV season) and a no-preventive option. A best-worst scaling (BWS) exercise was included to explore the impact of additional attributes on preventive preferences. Data were collected between October and November 2022. Attribute-level preference weights and relative importance (RI) were estimated. Overall, 992 pregnant people and 310 HCPs participated. A preventive (vs. none) was chosen 89.2% (pregnant people) and 96.0% (HCPs) of the time (DCE). Effectiveness was most important to preventive choice for pregnant people (RI = 48.0%) and HCPs (RI = 41.7%); all else equal, pregnant people (RI = 5.5%) and HCPs (RI = 7.2%) preferred the maternal vaccine over mAbs, although preventive type had limited influence on choice. Longer protection, protection starting at birth or the beginning of RSV season, and use for both pre-term and full-term babies were ranked highest in importance (BWS). Pregnant people and HCPs strongly preferred a preventive to protect infants against RSV (vs. none), underscoring the need to incorporate RSV preventives into routine care.

A Psychometric Study of the Arabic Version of the "Searching for Hardships and Obstacles to Shots (SHOT)" Instrument for Use in Saudi Arabia

Vaccines are considered one of the top 10 public health achievements of the 20th century and the most cost-effective public health intervention to overcome diseases and disease-associated mortality. This study translated the "Searching for Hardships and Obstacles to Shots" (SHOT) instrument from English to Arabic and conducted a psychometric evaluation of the Arabic version to measure parental barriers to childhood immunization. The cross-sectional study utilized multistage cluster random sampling to recruit parents visiting 70 primary health centers in Jizan. Scale translation and cultural adaptation were used to translate the SHOT survey into Arabic. The survey revealed that the best-factor model was a one-factor solution for "barriers to child immunization." The first principal component explained the highest variance (56.22%), and subsequent components explained decreasing percentages of variance. The third principal component explained the decreased variance (4.61%), and subsequent components explained the decreasing percentages of variance. The overall reliability (determined by Cronbach's alpha) was 0.96. The strong internal consistency of the Arabic version of the SHOT instrument (as indicated by the high Cronbach's alpha coefficients) indicates that researchers and practitioners can confidently use this scale to measure parents' attitudes toward and perceptions of vaccinations. Furthermore, the study results will help policymakers develop programs or interventional initiatives to overcome these barriers.

Preferences of pregnant women toward a future maternal Group B Streptococcus vaccine in China: A cross-sectional survey with a discrete choice experiment

Group B streptococcus (GBS) is a major cause of neonatal death worldwide. A GBS vaccine for pregnant women is under development and is expected to be available in the near future. The perceptions and preferences of pregnant women in China of GBS vaccines has not been investigated, and this study aimed to investigate pregnant women's awareness of GBS and their potential preferences for the GBS vaccine. A discrete choice experiment was conducted among pregnant women in hospitals from Shaanxi, Hunan, and Zhejiang provinces located in Western, Central, and Eastern China, respectively. A conditional logit model was used to analyze the data and calculate willingness to pay values and choice probabilities of different GBS vaccine programs. A total of 354 pregnant women were included in the final analysis, 45.8% of whom were willing to receive a GBS vaccine if it were licensed. Vaccine safety was the most important attribute of a future vaccine, while cost was the least important attribute. Compared with no vaccination, pregnant women had a strong preference for future GBS vaccination (ASC = 1.267, p < .001). Pregnant women's decisions were highly influenced by those of other pregnant women. Improving the safety, efficacy, and vaccination rate of the GBS vaccine in China is of great significance for future GBS vaccine development and vaccination. Compared to other variable options, the cost of a GBS vaccine was of the least importance among pregnant women in mainland China. These findings can inform public health policy decisions related to GBS vaccination in China.

Patient preferences for physical therapy programs after a lower extremity fracture: a discrete choice experiment

OBJECTIVE

To quantify patients' preferences for physical therapy programmes after a lower extremity fracture and determine patient factors associated with preference variation.

DESIGN

Discrete choice experiment.

SETTING

Level I trauma centre.

PARTICIPANTS

One hundred fifty-one adult (≥18 years old) patients with lower extremity fractures treated operatively.

INTERVENTION

Patients were given hypothetical scenarios and asked to select their preferred therapy course when comparing cost, mobility, long-term pain, session duration, and treatment setting.

MAIN OUTCOME MEASURES

A multinomial logit model was used to determine the relative importance and willingness to pay for each attribute.

RESULTS

Mobility was of greatest relative importance (45%, 95% CI: 40% to 49%), more than cost (23%, 95% CI: 19% to 27%), long-term pain (19%, 95% CI: 16% to 23%), therapy session duration (12%, 95% CI: 9% to 5%) or setting (1%, 95% CI: 0.2% to 2%). Patients were willing to pay US$142 more per session to return to their preinjury mobility level (95% CI: US$103 to US$182). Willingness to pay for improved mobility was higher for women, patients aged 70 years and older, those with bachelor's degrees or higher and those living in less-deprived areas. Patients were willing to pay US$72 (95% CI: US$50 to US$93) more per session to reduce pain from severe to mild. Patients were indifferent between formal and independent home therapy (willingness to pay: -US$12, 95% CI: -US$33 to US$9).

CONCLUSIONS

Patients with lower extremity fractures highly value recovering mobility and are willing to pay more for postoperative physical therapy programmes that facilitate returning to their pre-injury mobility level. These patient preferences might be useful when prescribing and designing new techniques for postoperative therapy.

Influenza vaccine uptake among children and older adults in China: a secondary analysis of a quasi-experimental study

BACKGROUND

Influenza vaccination is the key to prevent influenza-related disease, especially among high-risk populations. However, influenza vaccine uptake in China is low. This secondary analysis of a quasi-experimental trial aimed to understand factors associated with influenza vaccine uptake among children and older people stratified by funding context.

METHODS

A total of 225 children (aged 0.5-8 years) and 225 older people (aged 60 years or above) were recruited from three clinics (rural, suburban and urban) in Guangdong Province. Participants were allocated into two groups based on funding contexts: a self-paid group (N = 150, 75 children and 75 older adults) in which participants paid full price for their vaccination; and a subsidized group (N = 300, 150 children and 150 older adults) in which varying levels of financial support was provided. Univariate and multivariable logistic regressions were conducted stratified by funding contexts.

RESULTS

Overall, 75.0% (225/300) of participants in the subsidized group and 36.7% (55/150) in the self-paid group got vaccinated. Older adults had lower vaccination rates than children in both funding groups, while both age groups showed much higher uptake in the subsidized group than in the self-paid group (aOR = 5.96, 95% CI: 3.77-9.42, p = 0.001). In the self-paid group, having prior influenza vaccination history of children (aOR:2.61, 95%CI: 1.06-6.42) or older people (aOR:4.76, 95%CI: 1.08-20.90) was associated with increased influenza vaccine uptake compared to those who had no prior vaccination experiences in the family. While in the subsidized group, participants who got married or lived with partners (aOR = 0.32, 0.10-0.98) had lower vaccination uptake than single ones. Trust in providers' advice (aOR = 4.95, 95%CI:1.99, 12.43), perceived effectiveness of the vaccine (aOR: 12.18, 95%CI: 5.21-28.50), and experienced influenza-like illnesses in the family in the past year (aOR = 46.52, 4.10, 533.78) were associated with higher vaccine uptake.

CONCLUSIONS

Older people had suboptimal vaccine uptake compared to children in both contexts and need more attention to enhance influenza vaccination. Tailoring interventions to different vaccine funding contexts may help improve influenza vaccination: In self-paid context, motivating people to accept their first ever influenza vaccination may be a promising strategy. In subsidized context, improving public confidence in vaccine effectiveness and providers' advice would be useful.

The COVID-19 vaccination decision-making preferences of elderly people: a discrete choice experiment

COVID-19 is a continuing threat to global public health security. For elderly people, timely and effective vaccination reduces infection rates in this group and safeguards their health. This paper adopted an offline Discrete Choice Experiment (DCE) to research the preference for COVID-19 vaccination amongst Chinese adults aged 50 years and above. Through multinomial logistic regression analysis, our DCE leverages five attributes-the risk of adverse reactions, protective duration, injection doses, injection period, and effectiveness-each of which is split into three to four levels. The risk of adverse reaction and the protective duration were demonstrated to be determinants of vaccination preference. Moreover, it was found that socio demographic factors like region, self-health assessment and the number of vaccinated household members can strengthen or weaken the effects of vaccine attributes. In conclusion, the preferences of the elderly population should be considered when developing COVID-19 vaccination programs for this population in China. Accordingly, the results may provide useful information for policymakers to develop tailored, effectively vaccination strategies.

Parental Acceptance of COVID-19 Vaccination for Children and Its Association With Information Sufficiency and Credibility in South Korea

IMPORTANCE

Vaccination against COVID-19 is an effective method for individuals to reduce negative health outcomes. However, widespread COVID-19 vaccination among children has been challenging owing to parental hesitancy.

OBJECTIVE

To examine parental decision-making in favor of the COVID-19 vaccine for their children and its association with the sufficiency and credibility of the information about the vaccine.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional survey study was conducted in South Korea from February 7 to 10, 2022, 7 weeks before initiation of the COVID-19 vaccine for children aged 5 to 11 years. Parents were included if they spoke Korean and had at least 1 child in elementary school (grades 1-6). Parents and children were included in a 1:1 ratio; a total of 113 450 parents and 113 450 children were included in the analysis. Statistical analysis was performed between March and April 2022.

MAIN OUTCOMES AND MEASURES

The main outcomes of interest were (1) parental acceptance of COVID-19 vaccination for their children and (2) its association with self-reported sufficiency and credibility of information about the vaccine. A multivariable logistic regression was used to evaluate factors associated with parental decision-making in favor of COVID-19 vaccination; path analysis was used to examine indirect effects of information sufficiency and credibility.

RESULTS

Of the 113 450 children, 58 342 (51.4%) were boys, and the mean (SD) age was 10.1 (1.5) years. Of the 113 450 parents who responded, 7379 (6.5%) were accepting vaccination for their children; 15 731 (13.9%) reported the vaccine-related information they received was sufficient, and 23 021 (20.3%) reported the information was credible. Parents who reported that the information was sufficient were 3.08 times (95% CI, 2.85-3.33; P < .001) more likely to report being willing to vaccinate their children than those who believed the information was insufficient, and those who reported that the information was credible were 7.55 times (95% CI, 6.46-8.87; P < .001) more likely to report being willing to vaccinate their children than those who believed the information was not credible. Higher levels of information sufficiency and credibility were associated with perceptions of increased vaccine safety (sufficiency: β = 0.08; P < .001; credibility: β = 0.59; P < .001) and effectiveness (sufficiency: β = 0.05; P < .001; credibility: β = 0.60; P < .001).

CONCLUSIONS AND RELEVANCE

In this study, a significant association was found between self-reported sufficiency and credibility of vaccine-related information and parental decision-making regarding COVID-19 vaccination for their children, suggesting that communications and policies that provide sound information are essential to improve vaccination rates.

Life Satisfaction and Influenza Vaccination Among Older Adults in Canada

Older adults have an increased risk of complications or death from influenza. Despite the benefits of vaccination for older adults, vaccination coverage among older adults ages 65 years and over is still below Canada's national target of 80 per cent. As health-care-seeking behaviours are influenced by several factors, including life satisfaction, we investigated the relationship between life satisfaction and influenza vaccination among older adults. A sample (n = 22,424) from the 2015-2016 Canadian Community Health Survey data was analysed using descriptive and multinomial logistic regression analyses. Higher life satisfaction was associated with a more recent influenza vaccination history. Vaccination differed by gender, age, and self-reported health status, as women, much older adults, and those with the poorest health status were more likely to be vaccinated. The study suggests an association between life satisfaction and influenza vaccination. More research into the factors that impact influenza vaccination in older adults is needed to increase vaccination coverage in the older adult population.

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.

Malaysian public preferences and decision making for COVID-19 vaccination: A discrete choice experiment

BACKGROUND

Low vaccine uptake has the potential to seriously undermine COVID-19 vaccination programs, as very high coverage levels are likely to be needed for virus suppression to return life to normal. We aimed to determine the influence of vaccine attributes (including access costs) on COVID-19 vaccination preferences among the Malaysian public to improve national uptake.

METHODS

An online Discrete Choice Experiment (DCE) was conducted on a representative sample of 2028 Malaysians. Respondents were asked to make vaccination decisions in a series of hypothetical scenarios. A nested, mixed logit model was used to estimate the preferences for vaccination over vaccine refusal and for how those preferences varied between different sub-populations. The attributes were the risk of developing severe side effects of the vaccine, vaccine effectiveness, vaccine content, vaccination schedule, and distance from home to vaccination centre.

FINDINGS

Reported public uptake of COVID-19 vaccination was primarily influenced by the risk of developing severe side effects (b = -1·747, 95% CI = -2·269, -1·225), vaccine effectiveness (b = 3·061, 95% CI = 2·628, 3·494) and its Halal status (b = 3·722, 95% CI = 3·152, 4·292). Other factors such as appointment timing and travel distance to the vaccination centre also had an effect on vaccine uptake. There was substantial heterogeneity in preferences between different populations, particularly for age groups, ethnicity, regions, and underlying health conditions.

INTERPRETATION

Perceived effectiveness and side effects are likely to affect COVID-19 vaccine uptake in Malaysia. Halal content is critical to Malays' vaccination choices. Reducing the physical distance to vaccination centres, particularly in rural areas where uptake is lower, is likely to improve uptake.

FUNDING

Ministry of Health Research Grant from the Malaysian government [NIH/800-3/2/1 Jld.7(46), grant reference no: 57377 and warrant no: 91000776].

Public engagement in decision-making regarding the management of the COVID-19 epidemic: Views and expectations of the 'publics'

Background

In the management of epidemics, like COVID‐19, trade‐offs have to be made between reducing mortality and morbidity and minimizing socioeconomic and political consequences. Traditionally, epidemic management (EM) has been guided and executed attentively by experts and policymakers. It can, however, still be controversial in the public sphere. In the last decades, public engagement (PE) has been successfully applied in various aspects of healthcare. This leads to the question if PE could be implemented in EM decision‐making.

Methods

From June to October 2020, seven deliberative discussion focus groups were executed with 35 Dutch citizens between 19 and 84 years old. Their views on PE in COVID‐19 management were explored. The deliberative approach allows for the education of participants on the topic before the discussion. The benefits, barriers, timing and possible forms of PE in EM were discussed.

Results

Almost all participants supported PE in EM, as they thought that integrating their experiences and ideas would benefit the quality of EM, and increase awareness and acceptance of measures. A fitting mode for PE was consultation, as it was deemed important to provide the public with possibilities to share ideas and feedback; however, final authority remained with experts. The publics could particularly provide input about communication campaigns and control measures. PE could be executed after the first acute phase of the epidemic and during evaluations.

Conclusions

This paper describes the construction of an empirically informed framework about the values and conditions for PE in EM from the perspective of the public. Participants expressed support to engage certain population groups and considered it valuable for the quality and effectiveness of EM; however, they expressed doubts about the feasibility of PE and the capabilities of citizens. In future studies, these results should be confirmed by a broader audience.

Patient or Public Contribution

No patients or members of the public were involved in the construction and execution of this study. This study was very exploratory, to gain a first insight into the views of the public in the Netherlands, and will be used to develop engagement practices accordingly. At this stage, the involvement of the public was not yet appropriate.

Adult vaccination uptake strategies in low- and middle-income countries: A systematic review

BACKGROUND

Evidence-based strategies can maximize vaccination intent and uptake among adults. This systematic review summarizes the existing literature on strategies to improve vaccination intent and uptake among adults in low- and middle-income countries (LMICs) to inform future implementation in various populations and contexts.

METHODS

Eligible studies were identified through a systematic search in Medline, Embase, Cochrane Libraries, as well as grey literature databases published between January 2010 and March 2021. The search was limited to studies in LMICs that evaluated adult vaccination interventions. Data were extracted from the included studies and evaluated against the World Health Organization's Behavioral and Social Drivers of Vaccination Framework. The National Institutes of Health study quality assessment tools were used to evaluate study quality.

RESULTS

The initial literature review identified 2,854 records, 22 of which met the inclusion criteria. The majority (n = 19 or 86%) of studies were from middle-income countries, with the remaining studies (n = 3 or 13%) set in low-income countries. The majority (15/22, 68%) of interventions were multi-component. 82% (18/22) of studies addressed thoughts and feelings, 59% (13/22) addressed social processes, and 73% (16/22) addressed practical issues. Five studies reported primary outcomes of vaccination intent, and the remaining 17 reported vaccine uptake. 36% (8/22) of the studies cited statistically significant positive intervention effects on vaccination intent or uptake. Few of the included studies (6/22, 27%) were RTCs, and most studies (15/22, 68%) were of poor study quality. The studies reporting the highest increase in vaccination intent and uptake were multi-component interventions that addressed all three determinants of vaccination.

DISCUSSION

The results of this review highlight levers that can be used to encourage vaccine intent and uptake in the ongoing rollout of COVID-19 vaccines, as well as the deployment of other vaccines to adult populations in LMICs. Of the included studies, multicomponent interventions were most effective, mainly when targeting multiple determinants of vaccination. However, poor study quality indicates the need for additional research to validate these findings.

Measuring parents' readiness to vaccinate themselves and their children against COVID-19

To reach high vaccination rates against COVID-19, children and adolescents should be also vaccinated. To improve childhood vaccination rates and vaccination readiness, parents need to be addressed since they decide about the vaccination of their children. We adapted the 7C of vaccination readiness scale to measure parents' readiness to vaccinate their children and evaluated the scale in a long and a short version in two studies. The study was first evaluated with a sample of N = 244 parents from the German COVID-19 Snapshot Monitoring (COSMO) and validated with N = 464 parents from the Danish COSMO. The childhood 7C scale showed acceptable to good psychometric properties in both samples and explained more than 80% of the variance in vaccination intentions. Additionally, differences in parents' readiness to vaccinate their children against COVID-19 were strongly determined by their readiness to vaccinate themselves, explaining 64% of the variance. Vaccination readiness and intentions for children changed as a function of the children's age explaining 93% of differences between parents in their vaccination intentions for their children. Finally, we found differences in correlations of components with self- versus childhood vaccination, as well as between the children's age groups in the prediction of vaccination intentions. Thus, parents need to be targeted in specifically tailored ways, based on the age of their child, to reach high vaccination rates in children. The scale is publicly available in several languages (www.vaccination-readiness.com).

COVID-19 Vaccine Hesitancy among Behavioral Risk Takers

The COVID-19 pandemic has emerged as a major public health issue, with vaccines serving as a vital preventive strategy to lower the global burden. Yet, despite national and local mandates, key sectors of the population continue to demonstrate lower compliance rates. In the United States, young adults have the lowest vaccination rates among the adult population. The goal of our study was to utilize the largest state-health survey to assess the key determinants of such hesitancy in order to create targeted interventions for the most at-risk groups to ensure equitable outcomes in disease prevention. We utilized the latest available California Health Interview Survey, a population-based complex probability survey, to evaluate determinants of vaccine hesitancy among young adults. Survey-weighted descriptive statistics, bivariate statistics, and multivariable logistic regression analyses were conducted. All statistical tests used p less than 0.05 to determine statistical significance. A total of 1203 respondents, representative of 4,027,462 young adults (ages 18–25 years) were included in our study. Our primary findings note that 24% of participants reported they would not be willing to take the COVID-19 vaccination. Prevalence of vaccine hesitancy was also significantly higher among young adults who were current smokers (including electronic cigarettes), when compared to non-current smokers (36% vs. 22%). Further, the highest prevalence was also noted among young adults who identified as African-American (51%), had a high school degree or less (34%), those who were overweight or obese (28%), and reported a poor health status (22%). Multivariable regression analysis demonstrated that current smokers, as compared to non-current smokers, had more than double the odds of reporting COVID-19 vaccine hesitancy. African-American young adults or young adults with a high school degree or less were both independently associated with at least a three-fold increase in vaccine hesitancy. Participants with psychological distress, however, were more likely to be accepting of the vaccine. Public health efforts to improve vaccine compliance need targeted efforts, including building trust in the healthcare system for African-Americans and promoting easier access and knowledge of vaccines among those with a high school degree or less, as well as young-adults who are currently smoking, with such efforts targeting behavioral interventions focused on risk aversion.

The Prevalence and Impact of Fake News on COVID-19 Vaccination in Taiwan: Retrospective Study of Digital Media

BACKGROUND

Vaccination is an important intervention to prevent the incidence and spread of serious diseases. Many factors including information obtained from the internet influence individuals' decisions to vaccinate. Misinformation is a critical issue and can be hard to detect, although it can change people's minds, opinions, and decisions. The impact of misinformation on public health and vaccination hesitancy is well documented, but little research has been conducted on the relationship between the size of the population reached by misinformation and the vaccination decisions made by that population. A number of fact-checking services are available on the web, including the Islander news analysis system, a free web service that provides individuals with real-time judgment on web news. In this study, we used such services to estimate the amount of fake news available and used Google Trends levels to model the spread of fake news. We quantified this relationship using official public data on COVID-19 vaccination in Taiwan.

OBJECTIVE

In this study, we aimed to quantify the impact of the magnitude of the propagation of fake news on vaccination decisions.

METHODS

We collected public data about COVID-19 infections and vaccination from Taiwan's official website and estimated the popularity of searches using Google Trends. We indirectly collected news from 26 digital media sources, using the news database of the Islander system. This system crawls the internet in real time, analyzes the news, and stores it. The incitement and suspicion scores of the Islander system were used to objectively judge news, and a fake news percentage variable was produced. We used multivariable linear regression, chi-square tests, and the Johnson-Neyman procedure to analyze this relationship, using weekly data.

RESULTS

A total of 791,183 news items were obtained over 43 weeks in 2021. There was a significant increase in the proportion of fake news in 11 of the 26 media sources during the public vaccination stage. The regression model revealed a positive adjusted coefficient (β=0.98, P=.002) of vaccine availability on the following week's vaccination doses, and a negative adjusted coefficient (β=-3.21, P=.04) of the interaction term on the fake news percentage with the Google Trends level. The Johnson-Neiman plot of the adjusted effect for the interaction term showed that the Google Trends level had a significant negative adjustment effect on vaccination doses for the following week when the proportion of fake news exceeded 39.3%.

CONCLUSIONS

There was a significant relationship between the amount of fake news to which the population was exposed and the number of vaccination doses administered. Reducing the amount of fake news and increasing public immunity to misinformation will be critical to maintain public health in the internet age.

Optional Vaccines in Children—Knowledge, Attitudes, and Practices in Romanian Parents

Vaccination is one of the most useful medical interventions for controlling certain infectious diseases. The aim of current research is to identify some of the drivers of vaccine hesitancy or acceptance in a rather skeptical European population by addressing parental perception on optional vaccination (OV) perception. Novel tools, delivered by social media, were used in our research attempt. A validated questionnaire was distributed online among parents. Parental knowledge, attitudes and perceptions of OV were analyzed. The majority of parent respondents (55.1%) showed very good knowledge about vaccination and vaccine-preventable diseases, and 76.0% stated that they had given at least one optional vaccine to at least one of their children. The most common optional vaccine administered was the rotavirus vaccine. The level of knowledge appeared to be related to compliance with OV. Concurrently, the rate of vaccine acceptance in the NIP (National Immunization Program) was not correlated with the level of parental knowledge. In total, a high percentage of parents (77.6%) believed that OV can bring an additional health safety benefit to their children. This study shows the need to involve the medical community in a steady dialogue with parents about OV. Raising awareness by presenting clear and understandable information could be a game-changing intervention in mitigating the public health impact of OV-preventable diseases.

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.

Impact of information framing and vaccination characteristics on parental COVID-19 vaccine acceptance for children: a discrete choice experiment

This study aimed to test the influence of vaccination characteristics and gain/loss-framing of information, on parental acceptance of the coronavirus disease 2019 (COVID-19) vaccination for their minor children. A discrete choice experiment was conducted among parents of children aged 0-17 years from September to October 2021 in Hong Kong. Respondents were randomly assigned to four groups with different framing of information and asked to choose hypothetical vaccination alternatives, described by seven attributes that were derived from prior qualitative interviews. A mixed logit model was adopted to analyze the effect of attributes and information framing on parental vaccination acceptance. The vaccine acceptance rates under different scenarios were also estimated. A total of 298 valid responses were obtained. It was found that the BioNTech brand, higher efficacy, less serious adverse events and more vaccination coverage in children significantly improved parental acceptance. Additionally, loss-framing increased parental acceptance compared with gain-framing, while the presentation of mortality information did not make a difference. Acceptance was also associated with parental uptake of the COVID-19 vaccine and the children's age.

CONCLUSION

The findings imply that factors including gain/loss information framing, importance of vaccine characteristics, and peer influence have a significant effect on parents' decisions to get their children vaccinated. Parents with younger children had greater vaccine hesitancy, and information framing techniques should be considered in vaccination promotion for combating such vaccine hesitancy. Future studies could be conducted to identify the moderators and mediators of information framing to facilitate its implementation.

WHAT IS KNOWN

• Parental acceptance of COVID-19 vaccine was found to be associated with various socio-economic and psychosocial factors, while the evidence on impact of vaccination characteristics was limited. • Behavioral interventions, including information framing, have been used to promote various health behaviors.

WHAT IS NEW

• Loss-framing of information on vaccine effectiveness improves vaccine acceptance, while additional information on how the vaccine reduces death does not make a difference, which can be used to inform communication with the public in vaccination promotion. • The social norm (i.e., the vaccine uptake amongst other people) is important for increasing the parental vaccine acceptance rate.

Influence of Vaccination Characteristics on COVID-19 Vaccine Acceptance Among Working-Age People in Hong Kong, China: A Discrete Choice Experiment

Background: Along with individual-level factors, vaccination-related characteristics are important in understanding COVID-19 vaccine hesitancy. This study aimed to determine the influence of these characteristics on vaccine acceptance to formulate promotion strategies after considering differences among respondents with different characteristics.

Methods: An online discrete choice experiment was conducted among people aged 18–64 years in Hong Kong, China, from 26 to 28 February 2021. Respondents were asked to make choices regarding hypothetical vaccination programmes described by vaccination-related characteristics—the attributes derived from a prior individual interview. Subgroup analysis was performed to identify the differences in vaccination-related characteristics among respondents with different personal characteristics.

Results: A total of 1,773 respondents provided valid responses. The vaccine efficacy and brand were the most important factors affecting acceptance, followed by the exemption of quarantine for vaccinated travelers, safety, venue for vaccination, vaccine uptake of people in their lives, and recommendations by general physicians or government. Frequent exposure to vaccination information on social media has been associated with increasing vaccine refusal. Substantial preference heterogeneity for the attributes was found among people of different ages, incomes, chronic conditions, and previous acceptance of influenza vaccines.

Conclusion: The findings provided evidence to formulate interventions to promote vaccine uptake, including the provision of vaccination at housing estate or workplaces, involvement of general physicians and interpersonal communication in vaccine promotion and information dissemination, and exemption of quarantine for vaccinated people. Moreover, social media is a significant information channel that cannot be neglected in the dissemination of official information.

Factors driving choices between types and brands of influenza vaccines in general practice in Austria, Italy, Spain and the UK

Influenza vaccine effectiveness (IVE) assessment is increasingly stratified by vaccine type or brand, such as done by the European network of DRIVE. In 2019/2020, eleven influenza vaccines were licensed in Europe. If more than one vaccine type is recommended or if more than one vaccine brand is available for a specific risk group, it is not clear which factors affect the choice of a specific vaccine (type or brand) by a health practitioner for individual patients. This is important for IVE assessment. A survey tailored to the 2019/20 local vaccine recommendations was conducted among GPs in four European countries (Austria, Italy, Spain, UK) to understand how influenza vaccine is offered to recommended risk groups and, if GPs have a choice between 2 or more vaccines, what factors influence their vaccine choice for patients. Overall, 360 GPs participated. In Austria, Italy and Spain GPs indicated that influenza vaccines are commonly offered when patients present for consultation, whereas in the UK all GPs indicated that all relevant patients are contacted by letter. In Austria and Italy, roughly 80% of GPs had only one vaccine type available for patients <65y. The use of any specific vaccine type in this age group is mostly determined by the availability of specific vaccine type(s) at the clinic. GPs frequently reported availability of more than one vaccine type for patients ≥65y in Austria (45%), Italy (70%) and Spain (79%). In this group, patient characteristics played a role in choice of vaccine, notably older age and presence of (multiple) comorbidities. Knowing that a non-patient related factor usually determines the vaccine type a patient receives in settings where more than one vaccine type is recommended for risk groups <65y, simplifies IVE assessment in this age group. However, patient characteristics need careful consideration when assessing IVE in those ≥65y.

Societal Effects Are a Major Factor for the Uptake of the Coronavirus Disease 2019 (COVID-19) Digital Contact Tracing App in The Netherlands

OBJECTIVES

Our study investigates the extent to which uptake of a COVID-19 digital contact-tracing (DCT) app among the Dutch population is affected by its configurations, its societal effects, and government policies toward such an app.

METHODS

We performed a discrete choice experiment among Dutch adults including 7 attributes, that is, who gets a notification, waiting time for testing, possibility for shops to refuse customers who have not installed the app, stopping condition for contact tracing, number of people unjustifiably quarantined, number of deaths prevented, and number of households with financial problems prevented. The data were analyzed by means of panel mixed logit models.

RESULTS

The prevention of deaths and financial problems of households had a very strong influence on the uptake of the app. Predicted app uptake rates ranged from 24% to 78% for the worst and best possible app for these societal effects. We found a strong positive relationship between people's trust in government and people's propensity to install the DCT app.

CONCLUSIONS

The uptake levels we find are much more volatile than the uptake levels predicted in comparable studies that did not include societal effects in their discrete choice experiments. Our finding that the societal effects are a major factor in the uptake of the DCT app results in a chicken-or-the-egg causality dilemma. That is, the societal effects of the app are severely influenced by the uptake of the app, but the uptake of the app is severely influenced by its societal effects.

Can financial payments incentivize short-term smoking cessation in orthopaedic trauma patients? Evidence from a discrete choice experiment

BACKGROUND

Smoking increases the risk of complications and related costs after an orthopaedic fracture. Research in other populations suggests that a one-time payment may incentivize smoking cessation. However, little is known on fracture patients' willingness to accept financial incentives to stop smoking; and the level of incentive required to motivate smoking cessation in this population. This study aimed to estimate the financial threshold required to motivate fracture patients to stop smoking after injury.

METHODS

This cross-sectional study utilized a discrete choice experiment (DCE) to elicit patient preferences towards financial incentives and reduced complications associated with smoking cessation. We presented participants with 12 hypothetical options with several attributes with varying levels. The respondents' data was used to determine the utility of each attribute level and the relative importance associated with each attribute.

RESULTS

Of the 130 enrolled patients, 79% reported an interest in quitting smoking. We estimated the financial incentive to be of greater relative importance (ri) (45%) than any of the included clinical benefits of smoking cessations (deep infection (ri: 24%), bone healing complications (ri: 19%), and superficial infections (ri: 12%)). A one-time payment of $800 provided the greatest utility to the respondents (0.64, 95% CI: 0.36 to 0.93), surpassing the utility associated with a single $1000 financial incentive (0.36, 95% CI: 0.18 to 0.55).

CONCLUSIONS

Financial incentives may be an effective tool to promote smoking cessation in the orthopaedic trauma population. The findings of this study define optimal payment thresholds for smoking cessation programs.

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

Increased vaccine hesitancy and refusal negatively affects vaccine uptake, leading to the reemergence of vaccine preventable diseases. We aim to quantify the relative importance of factors people consider when making vaccine decisions for themselves, or for their child, with specific attention for underlying motives arising from context, such as required effort (accessibility) and opportunism (free riding on herd immunity). We documented attitudes towards vaccination and performed a discrete choice experiment in 4802 respondents in The United Kingdom, France and Belgium, eliciting preferences for six attributes: (1) vaccine effectiveness, (2) vaccine preventable disease burden, (3) vaccine accessibility in terms of copayment, vaccinator and administrative requirements, (4) frequency of mild vaccine-related side-effects, (5) vaccination coverage in the country’s population and (6) local vaccination coverage in personal networks. We distinguished adults deciding on vaccination for themselves from parents deciding for their youngest child. While all attributes were found to be significant, vaccine effectiveness and accessibility stood out in all (sub)samples, followed by vaccine preventable disease burden. We confirmed that people attach more value to severity of disease compared to its frequency, and discovered that peer influence dominates free-rider motives, especially for the vaccination of children. These behavioral data are insightful for policy and are essential to parameterize dynamic vaccination behavior in simulation models. In contrast to what most game theoretical models assume, social norms dominate free-rider incentives. Policy-makers and healthcare workers should actively communicate on high vaccination coverage, and draw attention to the effectiveness of vaccines while optimizing their practical accessibility.

Efficacy or delivery? An online Discrete Choice Experiment to explore preferences for COVID-19 vaccines in the UK

COVID-19 vaccines are widely regarded as an integral component in the UK's pandemic recovery, and a comprehensive distribution strategy will be required to maximise uptake. However, to date, there is a dearth of research into factors that could lead to UK residents' acceptance or rejection of COVID-19 vaccines. This study used a discrete choice experiment to investigate the importance of vaccine properties, delivery and media coverage in amplifying or attenuating vaccine uptake. Efficacy was found to be the factor that most influenced vaccine selection; further, the positive effect of high efficacy was more pronounced for those aged 55+. Insights from this DCE aim to assist policymakers and public health communicators in planning and refining their delivery strategy for COVID-19 vaccines.

Impact of Recommended Maternal Vaccination Programs on the Clinical Presentation of SARS-CoV-2 Infection: A Prospective Observational Study

The COVID-19 pandemic has raised questions about the possible cross immunity resulting from common vaccination programs and SARS-CoV-2 infection. Therefore, the Spanish Obstetric Emergency group performed a multicenter prospective study on the vaccination status of Influenza and Tdap (diphtheria, tetanus and pertussis vaccine boost administered in adulthood) in consecutive cases of SARS-CoV-2 infection in a pregnancy cohort, in order to assess its possible association with the clinical presentation and severity of symptoms of SARS-CoV-2 infection, as well as to determine the factors that may affect vaccination adherence. A total of 1150 SARS-CoV-2 positive pregnant women from 78 Spanish hospitals were analyzed: 183 had not received either vaccine, 23 had been vaccinated for Influenza only, 529 for Tdap only and 415 received both vaccines. No association was observed between the vaccination status and the clinical presentation of SARS-CoV-2 infection and/or the severity of symptoms. However, a lower adherence to the administration of both vaccines was observed in the Latin-American subgroup. Based on the results above, we reinforce the importance of maternal vaccination programs in the actual pandemic. Health education campaigns should be specially targeted to groups less likely to participate in these programs, as well as for a future SARS-CoV-2 vaccination campaign.