Public acceptance and willingness-to-pay for a future dengue vaccine: a community-based survey in Bandung, Indonesia

The role of antibody-dependent enhancement in dengue vaccination

Dengue is the most rapidly spreading vector-borne disease worldwide, with over half the global population at risk for an infection. Antibody-dependent enhancement (ADE) is associated with increased disease severity and may also be attributable to the deterioration of disease in vaccinated people. Two dengue vaccines are approved momentarily, with more in development. The increasing use of vaccines against dengue, combined with the development of more, makes a thorough understanding of the processes behind ADE more important than ever. Above that, due to the lack of treatment options, this method of prevention is of great importance. This review aims to explore the impact of ADE in dengue vaccinations, with the goal of enhancing potential vaccination strategies in the fight against dengue.

Acceptability of a hypothetical dengue vaccine and the potential impact of dengue vaccination on personal vector control behavior: a qualitative study in Fortaleza, Brazil

BACKGROUND

Dengue is the most rapidly spreading viral vector-borne disease in the world. Promising new dengue vaccines have contributed to a growing consensus that effective dengue control will require integrated strategies of vaccination and vector control. In this qualitative study, we explored the perspectives of residents of Fortaleza, Brazil on acceptability of a hypothetical safe and effective dengue vaccine, specific drivers of dengue vaccine acceptance or hesitance, and the expected impact of dengue vaccination on their personal vector control practices.

METHODS

A total of 43 in-depth interviews were conducted from April to June 2022 with Fortaleza residents from a diverse range of educational and professional backgrounds, with and without recent personal experiences of symptomatic dengue infections. Data were analyzed using the principles of inductive grounded theory methodology.

RESULTS

Our findings indicate that knowledge of dengue transmission, symptoms, and prevention methods was strong across respondents. Respondents described willingness to accept a hypothetical dengue vaccine for themselves and their children, while emphasizing that the vaccine must be demonstrably safe and effective. Respondents expressed diverse perspectives on how receiving a safe and effective dengue vaccine might influence their personal vector control behaviors, relating these behaviors to their perception of risk from other Aedes mosquito-carried infections and beliefs about the role of vector control in maintaining household cleanliness.

CONCLUSIONS

Our study findings provide community-level perspectives on dengue vaccination and its potential impact on personal vector control behavior for policymakers and program managers in Fortaleza to consider as new dengue vaccines become available. With the introduction of any new dengue vaccine, community perspectives and emerging concerns that may drive vaccine hesitancy should be continuously sought out. Improved urban infrastructure and efforts to engage individuals and communities in vector control may be needed to optimize the impact of future dengue vaccinations and prevent rising cases of other arboviruses such as Zika and chikungunya.

Parents' willingness to pay for COVID-19 vaccination for children in Malaysia using the contingent valuation method

Children are susceptible and a potential source of transmission for coronavirus disease 2019 (COVID-19). However compulsory COVID-19 vaccination programs among children have not been a focus in Malaysia. The aim of this study was to measure parents' willingness to pay (WTP) for the COVID-19 vaccine and analyze the effects of socioeconomic variables on parents' WTP. An online cross-sectional study was conducted in Malaysia with two waves of surveys (i.e., different samples for each wave), March and June 2021. The study participants were Malaysian parents above 18 years old. Parents were randomized between two vaccine effectiveness profiles (95% and 50% effectiveness) and two risk levels of an adverse event (5% and 20% risk of fever). The WTP was estimated using a double-bounded dichotomous choice. Socioeconomic variables such as age of parent, gender, insurance, income, and education were examined. A total of 292 parents in March 2021 and 271 in June 2021 were included in the study. The vaccine safety and effectiveness profile did not significantly impact the WTP. In March 2021, the estimated WTP ranged from RM344.74 to RM399.64 (US$82.5 to US$95.6) across vaccine profiles and between RM377.55 and RM444.33 (US$90.3 to US$106.3) in June. Insurance status was associated with the parents' WTP, and during the June wave, the age of parents influenced the WTP. Implementing subsidies or free vaccinations is considerable to increase herd immunity and prevent transmission of COVID-19 in Malaysia.

Dengue vaccine acceptance and willingness to pay: a systematic review and meta-analysis

OBJECTIVE

Dengue is the most important human vector-borne disease in terms of disease burden. A first dengue vaccine has recently been licenced, and others are in advanced stages of development. However, to date, none of these vaccines has achieved balanced efficacy and safety for all dengue serotypes. The aim of this systematic review and meta-analysis was to assess the global acceptance and willingness to pay for unspecified dengue vaccines.

METHODS

This systematic review and meta-analysis included cross-sectional and cohort studies that reported values for vaccine acceptance (percentage) and willingness to pay for currently available or hypothetical vaccines. These values were pooled using random-effects models for the acceptance, while weighted linear regression was chosen for willingness to pay. Heterogeneity between studies was assessed using prediction intervals (PIs), and a domain-based tool was used to assess the risk of bias. Subgroup and sensitivity analyses were performed where appropriate. This study was registered with PROSPERO (CRD42021255784).

RESULTS

We included 19 studies from the Americas and Asia in the quantitative meta-analysis. The risk of bias was mainly related to the selection of participants and to the assumptions about the safety and efficacy of the vaccines. The percentage of vaccine acceptance was 88.3% (95% CI: 81.0%-93.0%), with some heterogeneity between studies (80% PI: 52.9%-98.1%). Willingness to pay was US$ 46.7 (95% CI: 25.9-67.5) per vaccine recipient. There were differences between continents, with higher acceptance in the Americas.

CONCLUSIONS

We were able to obtain global estimates of vaccine acceptance and willingness to pay and identify the associated factors that influence these values. This knowledge is relevant for the planning of future vaccination strategies.

Application of the double bounded dichotomous choice model to the estimation of parent's willingness to pay for the hand foot mouth disease vaccination: A survey in Selangor, Malaysia

Hand foot and mouth disease (HFMD) is a notifiable viral disease in Malaysia, and is transmitted primarily among young children. Although vaccines for enteroviruses 71 (EV-71) were approved in China against HFMD, the availability and the acceptance of the vaccine in the Malaysia are unknown. This study investigated and ascertained the determinants of willingness-to-pay (WTP) for HFMD vaccination in Selangor Malaysia. This study adopted a cross-sectional, contingent valuation method involving 390 parents of young children aged six and below. The double bounded dichotomous choice (DBDC) approach was employed to assess the WTP for HFMD vaccine among respondents. A bivariate probit model was used to assess the key determinants of WTP for HFMD vaccine, while the mean WTP was measured using the Krinsky and Robb procedure. We found that 279 (71.5%) of parents were willing to pay for the HFMD vaccination. The estimated single bounded mean WTP was MYR460.23 (equivalent to US$ 102.17) for two doses of HFMD vaccination. The double bounded analysis revealed that the vaccine's price, poor education background and lower income were the key factors that significantly affected the WTP, with the estimated mean WTP being MYR394.00 (US$ 87.47). In conclusion, most Malaysian parents are willing to pay for the HFMD vaccination. The estimated WTP identifies the optimal price point for HFMD vaccination in Malaysia. Furthermore, the government should focus on an awareness programme for the HFMD vaccination among parents who have lower income or education level.

Knowledge, Attitudes and Practices toward Dengue Fever, Vector Control, and Vaccine Acceptance Among the General Population in Countries from Latin America and Asia Pacific: A Cross-Sectional Study (GEMKAP)

Dengue represents a major public health concern. With effective vaccines in development, it is important to identify motivational factors to maximize dengue vaccine uptake. A cross-sectional, quantitative, electronic survey was administered to a nationally representative adult population (n = 3800) in Argentina, Brazil, Colombia, Mexico, Indonesia, Malaysia, and Singapore. Willingness to vaccinate against dengue, and Knowledge, Attitudes, and Practices (KAP) toward dengue, vector control, prevention, and vaccination were determined. The Capability, Opportunity, Motivation for Behavior change (COM-B) framework was used to identify factors correlated with dengue vaccine(s) uptake. KAP scores (standardized, 0–100% scale) resulted in a low global score for Knowledge (48%) and Practice (44%), and a moderate score for Attitude (66%); scores were comparable across countries. Of all respondents, 53% had a high willingness (Score: 8–10/10) to vaccinate against dengue, which was higher (59%) in Latin America (Argentina, Brazil, Colombia, Mexico) than in Asia Pacific (40%) (Indonesia, Malaysia, Singapore). Key factors significantly (p < 0.05) associated with increased willingness to vaccinate included accessibility to the public (subsidies and incentives) and trust in the healthcare system and government. A common approach to dengue prevention across endemic countries––with some country-specific customization, including education, vaccination, and vector control (multi-pronged)––may reduce dengue burden and improve outcomes.

Acceptability of a Chikungunya Virus Vaccine, United States Virgin Islands

Chikungunya virus, a mosquito-borne alphavirus, causes acute febrile illness with polyarthralgia. Groups at risk for severe disease include neonates, people with underlying medical conditions, and those aged ≥ 65 years. Several chikungunya vaccines are in late clinical development with licensure expected in the United States during 2023. We administered a questionnaire to randomly selected households in the U.S. Virgin Islands (USVI) to assess interest in a hypothetical chikungunya vaccine. Estimates were calibrated to age and sex of USVI population, and univariate and multivariable analyses were performed. Of 966 participants, 520 (adjusted 56%, 95% CI = 51-60%) were interested in receiving the vaccine. Of 446 participants not interested in vaccination, 203 (adjusted 47%, 95% CI = 41-52%) cited safety concerns as the reason. Educational efforts addressing vaccine safety concerns and risk factors for severe disease would likely improve vaccine acceptability and uptake among those most at risk.

The main decision-making competence for willingness-to-pay towards COVID-19 vaccination: a family-based study in Taizhou, China

PURPOSE

This research aimed to explore individuals' willingness to pay (WTP) and studied the role of family decision makers in WTP for COVID-19 vaccines.

METHODS

A self-administered online questionnaire evaluating the willingness of community residents to pay for booster vaccination of COVID-19 vaccine was conducted among families in a community in Taizhou, China. The logistic regression model was performed to identify the factors associated with WTP for the COVID-19 vaccines, and all data were analysed by R software, version 4.1.0.

RESULTS

44.2% and 43.7% of 824 community residents were willing to pay for the first two doses and the booster dose of the COVID-19 vaccine, respectively. Decision-makers were more willing to pay for both the first two doses and the boost dose of the COVID-19 vaccines, with OR (95%CI) being 1.75 (1.25-2.47) and 1.89 (1.34-2.67), respectively. Besides, participants' WTP for COVID-19 vaccines were also associated with their occupation and monthly household income.

CONCLUSION

This study found that family decision-makers were more willing to pay for both the first two doses and the booster dose of COVID-19 vaccines in Taizhou, China. To improve the WTP for COVID-19 vaccines, public policy programs need to conduct a comprehensive cost-benefit analysis and focus on the role of family decision makers in vaccination.Key MessagesA study evaluating the willingness of community residents to pay for booster vaccination of COVID-19 vaccine was conducted among families in a community in Taizhou, China.Family decision-makers were more willing to pay for both the first two doses and the booster dose of COVID-19 vaccines.To improve the WTP for COVID-19 vaccines, public policy programs need to conduct a comprehensive cost-benefit analysis and focus on the role of family decision-makers in vaccination.

Association between health and safety perceptions of COVID-19 vaccine and its uptake in Ghana

Background

Attitudes towards vaccines have affected COVID-19 vaccination programs in many countries. This study sought to evaluate the effects of general perceptions on the safety and health concerns and the confidence in COVID-19 vaccines on its uptake in Ghana.

Methods

A cross-sectional online survey was conducted between January and March 2021. The outcome variables for this study were "Taking mandatory COVID-19 vaccine" and "Taking voluntary COVID-19 vaccine". The data were subjected to both descriptive (frequency, percentages, and chi-square tests) and inferential (complementary log-log logistic regression) analyses.

Results

Out of 620 Ghanians who participated in the survey, about 80% of the participants believed that vaccines were good for one's health and 73% had confidence on COVID-19 vaccine safety; although 81% of the respondents were particularly concerned about the source of the vaccine. 79% and 71% of respondents indicated their willingness for mandatory and voluntary COVID-19 vaccination, respectively. In all operationalized regression models, Ghanaians who believed that vaccines are healthy (OR = 1.998, Cl = 1.345-2.968; OR = 1.652, Cl = 1.050-2.601) and those who had confidence in a COVID-19 vaccine safety (OR = 4.405, Cl = 3.136-6.188; OR = 8.340, Cl = 5.471-12.713) were more likely to take a mandatory or voluntary COVID-19 vaccine compared to those who thought and believed otherwise. Individual preferences and/or intentions towards COVID-19 vaccine uptake and uptake route (i.e., mandatory, voluntary) were influenced by multifaceted determinants: biosocial (age, marital status, education), socio-cultural (religion, source of vaccine as a concern), and location (geographical zone) factors.

Conclusion

To consolidate and possibly increase vaccine uptake in response to the COVID-19 pandemic in Ghana, health education and promotion programs should aim at creating awareness on the benefits of vaccine uptake while addressing the health and safety concerns on the potential side effects through evidence-based community messaging from credible sources. It is important to show specific commitment to transparency and reliable information to build public trust by decision-makers.

“I would have to sell things in order to get the money”: A qualitative exploration of willingness to pay for the RTS,S/AS01 malaria vaccine in the Volta region, Ghana

Background

Malaria morbidity and mortality remain a challenge in Ghana. A promising childhood vaccine is being piloted in Ghana, however with the loss of its low-income status, Ghana is losing associated donor co-funding. User fees have been considered an alternative financing method, so this study utilised qualitative methods and explored caregivers’ willingness to pay for the malaria vaccine (RTS,S/AS01) to inform future service provision.

Methods

The study design was cross-sectional. Twenty in-depth interviews were conducted between February 2020 and March 2020 amongst a purposive sample of caregivers of RTS,S/AS01 eligible children, in the Volta region, Ghana. Interviews were audio-recorded and transcribed into English Language. Thematic analysis followed, using NVIVO12 to organise this data.

Results

Caregivers could distinguish between RTS,S/AS01 and routine vaccines and were willing to pay median GH₵5 (US$0.94), interquartile range GH₵3.75–5 (US$0.71–0.94) per dose of RTS,S/AS01. The maximum amount participants were willing to pay per dose was GH₵10 (US$1.88), interquartile range GH₵6–10 (US$1.13–1.88). Caregivers mentioned that they would work more to cover this cost because they were happy with services rendered to them during the RTS,S/AS01 pilot phase, and preferred vaccines over vector control measures. The results suggest that a willingness to pay was based on beliefs that the vaccine is fully effective. Although no participant declared that they would be unwilling to pay hypothetical user fees, there were still widespread concerns about affordability, with the majority feeling that the government should be responsible to pay for RTS,S/AS01.

Conclusions

Participants expressed a willingness to pay due to an appreciation of vaccines, shaped by personal experiences with immunisations and disease. Participants’ average income was lower than the national average, potentially affecting the perceived affordability of RTS,S/AS01. Because of the belief that RTS,S/AS01 is fully effective, caregivers may pay less attention to other preventative measures, thus unintentionally undermining malaria vector control.

Willingness to pay for a hypothetical malaria vaccine in Brazil: a cross-sectional study and the implications

Aim: Malaria is an infection caused by protozoa of genus Plasmodium, considered the one associated with increasingly large outbreaks. Methods: A cross-sectional study was conducted with residents in the northern region of Brazil on the willingness to pay (WTP) for a hypothetical vaccine against malaria (effective protection of 80%). Results: Of 616 people interviewed, most interviewees were female (61%) and were employed (97%). The median individual maximum WTP for a hypothetical malaria vaccine was US$11.90 (BRL 50). Conclusion: The northern region of Brazil is one of the largest markets for a malaria vaccine due to its epidemiological relevance. Consequently, economic studies will be important to assist in the assessment of the potential price and value of new vaccines.

Factors That Impact Acceptance of COVID-19 Vaccination in Different Community-Dwelling Populations in China

(1) Background: It is important to improve vaccination strategies and immunization programs to achieve herd immunity to infectious diseases. (2) Methods: To assess the acceptance of COVID-19 vaccination, we conducted face-to-face surveys and online surveys in Shanghai, Zhejiang, and Qinghai provinces. A fixed-effect model and a random effects model were used to analyze factors associated with the acceptance of COVID-19 vaccination. (3) Findings: We initially recruited 3173 participants, 3172 participants completed the full questionnaire (the response rate was nearly 100%), of which 2169 were valid questionnaires, with an effective rate of 87.3%. The results indicated that 82.6% of participants were willing to receive vaccination when it was available in the community, and 57.2% of deliverymen, 43.3% of medical workers, 78.2% of parents of primary and secondary school children, and 72.2% of parents of preschool children were willing to receive vaccination. The models showed that participants who were male (female vs. male: OR = 1.49, 95% CI (1.12, 1.98)), 60 to 69 years-old (60-69 vs. <30: OR = 0.52, 95% CI (0.29, 0.92)), had less education (medium vs. low: OR = 1.50, 95% CI (1.05, 2.23)), had good health status (good vs. low: OR = 0.36, 95% CI (0.15, 0.88)), and had positive attitudes and trust (OR = 0.14, 95% CI (0.10, 0.20)) in vaccines approved by the National Health Commission were more likely to accept vaccination. Participants also had an increased vaccination acceptance if it was recommended by government sources, doctors, relatives, or friends. Most participants learned about COVID-19 vaccination from television, radio, and newspapers, followed by community or hospital campaigns and the internet. (4) Conclusions: Government sources and doctors could increase the acceptance of vaccination by promoting the efficacy and safety of COVID-19 vaccination by the use of mass media and emphasizing the necessity of vaccination for everyone.

Taylor-Robinson A, Wu YS, Aung YN, Low WY, Sim MS, Sekaran SD, Azizan N. Different domains of dengue research in the Philippines: A systematic review and meta-analysis of questionnaire-based studies

Background

Dengue is the most rapidly spreading mosquito-borne viral disease of humans worldwide, including southeast Asia region. This review provides a comprehensive overview of questionnaire-related dengue studies conducted in the Philippines and evaluates their reliability and validity in these surveys.

Methods

A review protocol constructed by a panel of experienced academic reviewers was used to formulate the methodology, research design, search strategy and selection criteria. An extensive literature search was conducted between March–June 2020 in various major electronic biomedical databases including PubMed, EMBASE, MEDLINE and ScienceDirect. A systematic review and meta-analysis (PRISMA) were selected as the preferred item reporting method.

Results

Out of a total of 34 peer-reviewed dengue-related KAP studies that were identified, 15 published from 2000 to April 2020 met the inclusion criteria. Based on the meta-analysis, a poor mean score was obtained for each of knowledge (68.89), attitude (49.86) and preventive practice (64.69). Most respondents were equipped with a good knowledge of the major clinical signs of dengue. Worryingly, 95% of respondents showed several negative attitudes towards dengue prevention, claiming that this was not possible and that enacting preventive practices was not their responsibility. Interestingly, television or radio was claimed as the main source of gaining dengue information (range 50–95%). Lastly, only five articles (33.3%) piloted or pretested their questionnaire before surveying, of which three reported Cronbach’s alpha coefficient (range 0.70 to 0.90).

Conclusion

This review indicates that to combat the growing public health threat of dengue to the Philippines, we need the active participation of resident communities, full engagement of healthcare personnel, promotion of awareness campaigns, and access to safe complementary and alternative medicines. Importantly, the psychometric properties of each questionnaire should be assessed rigorously.

Acceptance of a COVID-19 Vaccine Before it is Available in China During the Pandemic

Objectives: China was believed to be the country with the world’s highest acceptance rate of the COVID-19 vaccine following several investigations. This study aims to explore the Chinese acceptance of a COVID-19 vaccine before it is made available, including its determinants.

Methods: A cross-national online survey was conducted covering all 31 provinces of mainland China. The survey consists of the demographic variables, acceptance of a self-paid COVID-19 vaccine as the dependent variable, and the 3Cs factors (i.e., confidence, convenience, and complacency) as the independent variables.

Results: Among the 1,532 participants, 57.9% accepted to get a self-paid COVID-19 vaccine. COVID-19 vaccine acceptors were more likely to be concerned about the effectiveness of the vaccines, believe that they were at risk of COVID-19 infection, have a high perceived susceptibility of COVID-19, and trust in the health care system.

Conclusion: Findings indicate that the critical task in the early stage of the COVID-19 vaccine development in China is to increase the tolerance to some intuitive concerns about the vaccines, put more emphasis on the communication of the saliency of the disease threats, and effectively translate people’s trust in the government into vaccine acceptance.

COVID-19 Vaccine Demand and Financial Incentives

BACKGROUND

Public health experts estimate that only very high COVID-19 vaccine uptake levels can result in herd immunity.

OBJECTIVE

This study's main objective was to evaluate the impact of vaccine price levels, including payments, and the efficacy levels on COVID-19 vaccine demand.

METHODS

Data for this study were collected from an online survey of 2000 US individuals aged 18 years and older, which included a set of contingent valuation questions. Parametric and nonparametric procedures were used to estimate the distribution of willingness-to-pay and willingness-to-accept values for the vaccine and to assess its association with vaccine efficacy levels (50, 70, and 95%).

RESULTS

Most of the individuals (60%) indicated they were willing to pay a positive amount for the vaccine; 13.7% said they would only accept the vaccine if it were free; 14.1% were willing to take the vaccine only if they were paid; and 12.2% were not willing to accept the vaccine. The vaccine efficacy level was found to affect an individual's demand for the vaccine. Estimated mean willingness-to-pay values were: US$594, US$706, and US$723 for vaccines with efficacy levels of 50, 70, and 95%, respectively.

CONCLUSIONS

US individuals highly value the COVID-19 vaccine, and about 88% of the US population would accept the vaccination; however, 14% indicated they would get vaccinated if compensated. Payments of about US$500 or more would be needed to sufficiently incentivize 50% or more of this group vaccinated.

The demand for a COVID-19 vaccine in Kenya

The goal of achieving herd immunity to the coronavirus requires high vaccination acceptance levels on the part of the population. The objectives of this study were to: 1) Measure individuals' willingness to pay (WTP) for a COVID-19 vaccine in Kenya; 2) evaluate the effect of vaccine characteristics (duration of protection and efficacy) and individuals' socioeconomic variables on WTP, and 3) estimate the aggregate demand and economic value of a COVID-19 vaccine. The contingent valuation (CV) method was used as the basis for the analyses. Data for this study were obtained from a survey of 1,050 individuals in Kenya conducted from April 7 to April 15, 2020. The survey included CV questions using a double-bounded dichotomous choice format. Results reveal that most of the individuals in Kenya (at least 96%) were willing to accept a COVID-19 vaccine. Approximately 80% of individuals were willing to pay a positive amount. Conservative estimates of individuals' mean WTP for the vaccine range from USD 49.81 to USD 68.25 (depending on vaccine characteristics). Both vaccine duration of protection and efficacy were found to influence WTP (p < .10). The perceived probability of being hospitalized, age, gender, education, location and region of residence, and household income were also found to be associated with WTP for the vaccine (p < .10). In conclusion, the COVID-19 vaccine is highly valued and accepted by the Kenyan population; however, a high percent of the population is unwilling to pay for it or is only willing to pay a low price.

Consumer willingness to pay for a hypothetical Chagas disease vaccine in Brazil: a cross-sectional study and the implications

Aim: Chagas disease is a serious public health problem, endemic in 21 countries in Latin America. A future vaccine can contribute to decreasing the number of cases and its complications. Methods: A cross-sectional study was conducted with residents of the northern region of Brazil, on the willingness to pay for a hypothetical vaccine against Chagas disease (effective protection of 80%). Results: We interviewed 619 individuals and seven were excluded from the analysis and the value of willingness to pay was US$23.77 (100.00 BRL). Conclusion: The Northern region of Brazil is one of the largest markets for this vaccine, due to its epidemiological relevance, so economic studies with this vaccine will be important to assist in the assessment of technologies.

Should germline genome editing be allowed? The effect of treatment characteristics on public acceptability

STUDY QUESTION

To what extent do characteristics of germline genome editing (GGE) determine whether the general public supports permitting the clinical use of GGE?

SUMMARY ANSWER

The risk that GGE would cause congenital abnormalities had the largest effect on support for allowing GGE, followed by effectiveness of GGE, while costs, the type of application (disease or enhancement) and the effect on child well-being had moderate effects.

WHAT IS KNOWN ALREADY

Scientific progress on GGE has increased the urgency of resolving whether and when clinical application of GGE may be ethically acceptable. Various expert bodies have suggested that the treatment characteristics will be key in determining whether GGE is acceptable. For example, GGE with substantial risks (e.g. 15% chance of a major congenital abnormality) may be acceptable to prevent a severe disease but not to enhance non-medical characteristics or traits of an otherwise healthy embryo (e.g. eye colour or perhaps in the future more complex traits, such as intelligence). While experts have called for public engagement, it is unclear whether and how much the public acceptability of GGE is affected by the treatment characteristics proposed by experts.

STUDY DESIGN, SIZE, DURATION

The vignette-based survey was disseminated in 2018 among 1857 members of the Dutch general public. An online research panel was used to recruit a sample representing the adult Dutch general public.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A literature review identified the key treatment characteristics of GGE: the effect on the well-being of the future child, use for disease or enhancement, risks for the future child, effectiveness (here defined as the chance of a live birth, assuming that if the GGE was not successful, the embryo would not be transferred), cost and availability of alternative treatments/procedures to prevent the genetic disease or provide enhancement (i.e. preimplantation genetic testing (PGT)), respectively. For each treatment characteristic, 2-3 levels were defined to realistically represent GGE and its current alternatives, donor gametes and ICSI with PGT. Twelve vignettes were created by fractional factorial design. A multinominal logit model assessed how much each treatment characteristic affected participants' choices.

MAIN RESULTS AND THE ROLE OF CHANCE

The 1136 respondents (response rate 61%) were representative of the Dutch adult population in several demographics. Respondents were between 18 and 89 years of age. When no alternative treatment/procedure is available, the risk that GGE would cause (other) congenital abnormalities had the largest effect on whether the Dutch public supported allowing GGE (coefficient = -3.07), followed by effectiveness (coefficient = 2.03). Costs (covered by national insurance, coefficient = -1.14), the type of application (disease or enhancement; coefficient = -1.07), and the effect on child well-being (coefficient = 0.97) had similar effects on whether GGE should be allowed. If an alternative treatment/procedure (e.g. PGT) was available, participants were not categorically opposed to GGE, however, they were strongly opposed to using GGE for enhancement (coefficient = -3.37). The general acceptability of GGE was higher than participants' willingness to personally use it (P < 0.001). When participants considered whether they would personally use GGE, the type of application (disease or enhancement) was more important, whereas effectiveness and costs (covered by national insurance) were less important than when they considered whether GGE should be allowed. Participants who were male, younger and had lower incomes were more likely to allow GGE when no alternative treatment/procedure is available.

LIMITATIONS, REASONS FOR CAUTION

Some (e.g. ethnic, religious) minorities were not well represented. To limit complexity, not all characteristics of GGE could be included (e.g. out-of-pocket costs), therefore, the views gathered from the vignettes reflect only the choices presented to the respondents. The non-included characteristics could be connected to and alter the importance of the studied characteristics. This would affect how closely the reported coefficients reflect 'real-life' importance.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first to quantify the substantial impact of GGE's effectiveness, costs (covered by national insurance), and effect on child well-being on whether the public considered GGE acceptable. In general, the participants were strikingly risk-averse, in that they weighed the risks of GGE more heavily than its benefits. Furthermore, although only a single study in one country, the results suggests that-if sufficiently safe and effective-the public may approve of using GGE (presumably combined with PGT) instead of solely PGT to prevent passing on a disease. The reported public views can serve as input for future consideration of the ethics and governance of GGE.

STUDY FUNDING/COMPETING INTEREST(S)

Young Academy of the Royal Dutch Academy of Sciences (UPS/RB/745), Alliance Grant of the Amsterdam Reproduction and Development Research Institute (2017-170116) and National Institutes of Health Intramural Research Programme. No competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Vaccination coverage and adherence to a dengue vaccination program in the state of Paraná, Brazil

The success of vaccination programs depends on the level of acceptance of the vaccine to achieve high vaccine coverage rates (VCR). Vaccine hesitancy is a challenge, especially concerning new vaccines. Dengue vaccine, Dengvaxia®, was licensed in Brazil in 2015 and implemented, in a pioneering publicly-funded initiative in the state of Paraná, between 2016 and 2018. The vaccination program took place in five phases in the 30 municipalities most affected by dengue in the state, targeting individuals from nine to 44 years-old in two cities and from 15 to 27 years-old in the other 28 municipalities, totaling a target population of 500,000 individuals. A cross-sectional descriptive study was carried out to assess VCR and adherence to the dengue vaccine in this program. VCR, dropout ratio (DR), and compliance with the vaccination schedule (CVS) were analyzed by sex, age group, and municipality size. A total of 302,603 individuals (60.5%) received ≥ 1 dose, 44.2% received ≥ 2 doses, and 28.6% 3 doses. The DR was 52.8%. Among individuals who started vaccination, 40.6% achieved CVS. The highest VCR, highest CVS, and lowest DR occurred in the age group from 9 to 14 years old and from 28 to 44 years old and in smaller municipalities. A greater proportion of men started vaccination (male 64.0%; female 57.1%) however, the DR was higher in men (male 55.4%; female 49.9%), and a higher percentage of women completed the vaccination schedule according to the recommendations (CVS male 37.8%; female 43.6%). Differences were noted in the CVS according to the initial phase of the program (first phase 50.8%; second phase 18.8%). The heterogeneity in vaccine uptake and compliance according to sex, age, and municipality size suggests the need for differentiated strategies to address challenges with new and multiple-dose vaccines.

Physicians’ willingness to be vaccinated with a smallpox vaccine to prevent monkeypox viral infection: A cross-sectional study in Indonesia

Background

Although there is no licensed vaccine for monkeypox, smallpox vaccine has been shown to be 85% effective in preventing the monkeypox. This study was conducted to assess the willingness of frontline healthcare providers to be vaccinated with smallpox vaccine to prevent monkeypox.

Methods

A cross-sectional study was conducted in Indonesia. The willingness was assessed under two scenarios: fully subsidized and non-subsidized vaccine. Explanatory variables such as sociodemographic profile, workplace and professional characteristics, and knowledge of monkeypox were collected. A logistic regression assessed the influence of these explanatory variables on participants’ willingness.

Results

Out of 510 received participants’ responses, 407 (79.8%) were analyzed. With a fully subsidized vaccine scenario, 381 (93.6%) of the participants were willing to be vaccinated and in an unadjusted analysis, gender, education, monthly income, and type of workplace were associated with willingness. With a non-subsidized vaccine (i.e. the vaccine price was US$ 17.9), the proportion who were willing to be vaccinated decreased to 71.9%. In adjusted analyses for both scenarios, gender was the only independent predictor for willingness; men were less willing to be vaccinated than women, adjusted odds ratio (aOR): 0.37; 95% confidence interval (CI): 0.16, 0.87 and aOR: 0.42; 95%CI: 0.27, 0.67, respectively for subsidized and non-subsidized scenario.

Conclusion

Vaccine price and gender are important factors for physicians' willingness to be vaccinated for smallpox vaccine prevent monkeypox in Indonesia. These findings indicate that achieving high vaccine converge may require partially or fully subsidized vaccines, along with a clear guideline and recommendation from authorities.

Willingness-to-pay for a COVID-19 vaccine and its associated determinants in Indonesia

How countries, particularly low- and middle-income economies, should pay the coronavirus disease 2019 (COVID-19) vaccine is an important and understudied issue. We undertook an online survey to measure the willingness-to-pay (WTP) for a COVID-19 vaccine and its determinants in Indonesia. The WTP was assessed using a simple dichotomous contingent valuation approach and a linear regression model was used to assess its associated determinants. There were 1,359 respondents who completed the survey. In total, 78.3% (1,065) were willing to pay for the COVID-19 vaccine with a mean and median WTP of US$ 57.20 (95%CI: US$ 54.56, US$ 59.85) and US$ 30.94 (95%CI: US$ 30.94, US$ 30.94), respectively. Being a health-care worker, having a high income, and having high perceived risk were associated with higher WTP. These findings suggest that the WTP for a COVID-19 vaccine is relatively high in Indonesia. This WTP information can be used to construct a payment model for a COVID-19 vaccine in the country. Nevertheless, to attain higher vaccine coverage, it may be necessary to partially subsidize the vaccine for those who are less wealthy and to design health promotion materials to increase the perceived risk for COVID-19 in the country.

Hypothetical assessment of efficiency, willingness-to-accept and willingness-to-pay for dengue vaccine and treatment: a contingent valuation survey in Bangladesh

In 2019, Bangladesh has grappled with a record-breaking surge in dengue fever, experiencing the highest number of dengue cases since the year 2000. Together, the intensification of dengue fever combined with a lack of dengue vaccines and appropriate medicines is expected to further the public and government's interests in appropriate and potential dengue vaccines to control the epidemic. We considered people's characteristics, dengue experience, and knowledge to assess their willingness-to-accept (WTA) and willingness-to-pay (WTP) for a hypothetical dengue vaccine and ex-post treatment in Bangladesh (June-July 2019). This study implemented a contingent valuation (CV) method with 3,251 respondents in 10 different locations of Bangladesh. All respondents participated in a hypothetical dengue vaccine scenario consisting of 65% (vaccine A), 80% (vaccine B), and 95% (vaccine C) effectiveness levels with three doses of each vaccine and ex-post dengue treatment. Around 71.2% of respondents were willing to pay for at least one of the hypothetical vaccines: A, B, or C. The average WTPs of the three vaccines amounted to US$ 47.0, US$ 66.0, and US$ 89.0, which were defined as the total cost of the doses necessary to obtain immunity. In Bangladesh, there is a significant demand for low-priced dengue vaccines, which was proven by people's higher acceptance of vaccination practices. Though dengue vaccines are not yet available in Bangladesh, this study provides significant support that both the government and private sectors should work together to develop a reliable and affordable dengue vaccine.

Acceptance of a COVID-19 Vaccine in Southeast Asia: A Cross-Sectional Study in Indonesia

Introduction: Several vaccine candidates are being clinically tested in response to the 2019 coronavirus disease (COVID-19) pandemic. This study was conducted to assess the acceptance of a 50 or 95% effective COVID-19 vaccine, when it becomes available in southeast Asia, among the general population in Indonesia. Methods: A cross-sectional online survey was conducted between March 25 and April 6, 2020. Participants were asked if they would accept a free vaccine which was 95 or 50% effective. Using a logistic regression model, we assessed the associations between sociodemographic characteristics, exposure to COVID-19 information, or perceived risk of infection with acceptance of a hypothetical COVID-19 vaccine. Results: Among 1,359 respondents, 93.3% of respondents (1,268/1,359) would like to be vaccinated for a 95% effective vaccine, but this acceptance decreased to 67.0% (911/1,359) for a vaccine with 50% effectiveness. For a 95% effective vaccine, being a healthcare worker and having a higher perceived risk of COVID-19 infection were associated with higher acceptance, adjusted odds ratio (aOR): 2.01; 95%CI: 1.01, 4.00 and aOR: 2.21; 95%CI: 1.07, 4.59, respectively; compared to civil servants, being retired was associated with less acceptance (aOR: 0.15; 95%CI: 0.04, 0.63). For a 50% effective vaccine, being a healthcare worker was also associated with greater acceptance, aOR: 1.57; 95%CI: 1.12, 2.20. Conclusion: Acceptance of a COVID-19 vaccine was highly influenced by the baseline effectiveness of the vaccine. Preparing the general population to accept a vaccine with relatively low effectiveness may be difficult.

Acceptance of a COVID-19 Vaccine in Southeast Asia: A Cross-Sectional Study in Indonesia

Introduction: Several vaccine candidates are being clinically tested in response to the 2019 coronavirus disease (COVID-19) pandemic. This study was conducted to assess the acceptance of a 50 or 95% effective COVID-19 vaccine, when it becomes available in southeast Asia, among the general population in Indonesia. Methods: A cross-sectional online survey was conducted between March 25 and April 6, 2020. Participants were asked if they would accept a free vaccine which was 95 or 50% effective. Using a logistic regression model, we assessed the associations between sociodemographic characteristics, exposure to COVID-19 information, or perceived risk of infection with acceptance of a hypothetical COVID-19 vaccine. Results: Among 1,359 respondents, 93.3% of respondents (1,268/1,359) would like to be vaccinated for a 95% effective vaccine, but this acceptance decreased to 67.0% (911/1,359) for a vaccine with 50% effectiveness. For a 95% effective vaccine, being a healthcare worker and having a higher perceived risk of COVID-19 infection were associated with higher acceptance, adjusted odds ratio (aOR): 2.01; 95%CI: 1.01, 4.00 and aOR: 2.21; 95%CI: 1.07, 4.59, respectively; compared to civil servants, being retired was associated with less acceptance (aOR: 0.15; 95%CI: 0.04, 0.63). For a 50% effective vaccine, being a healthcare worker was also associated with greater acceptance, aOR: 1.57; 95%CI: 1.12, 2.20. Conclusion: Acceptance of a COVID-19 vaccine was highly influenced by the baseline effectiveness of the vaccine. Preparing the general population to accept a vaccine with relatively low effectiveness may be difficult.

Willingness-to-pay for a hypothetical Ebola vaccine in Indonesia: A cross-sectional study in Aceh

Background: Some Ebola vaccines have been developed and tested in phase III clinical trials. However, assessment of whether public have willingness to purchase or not, especially in unaffected areas, is lacking. The aim of this study was to determine willingness to pay (WTP) for a hypothetical Ebola vaccine in Indonesia.

Methods: A cross-sectional study was conducted from 1 August to 30 December 2015 in five cities in Aceh province of Indonesia. Patients’ family members who visited outpatient departments were approached and interviewed about their sociodemographic characteristics, knowledge of Ebola, attitude towards vaccination practice and their WTP for a hypothetical Ebola vaccine. A multivariable linear regression model assessed the relationship between these explanatory variables and WTP.

Results: During the study, 500 participants were approached and interviewed. There were 424 (84.8%) respondents who completed the interview and 74% (311/424) expressed their acceptance for an Ebola vaccine. There were 288 participants who were willing to pay for an Ebola vaccine (92.6% out of 311). The mean of WTP was US$2.08 (95% CI: 1.75-2.42). The final multivariable model indicated that young age, high educational attainment, working as a private employee, entrepreneur or civil servant (compared to farmers), being unmarried, and residing in a suburb (compared to a city) were associated with higher WTP.

Conclusions: Although the proportion of the participants who would accept the Ebola vaccine was relatively high, the amount they were willing to pay for Ebola vaccine was very low. This finding would indicate the need of subsidies for Ebola vaccine in the country.

Willingness-to-pay for a hypothetical Ebola vaccine in Indonesia: A cross-sectional study in Aceh

Background: Some Ebola vaccines have been developed and tested in phase III clinical trials. However, assessment of whether public have willingness to purchase or not, especially in unaffected areas, is lacking. The aim of this study was to determine willingness to pay (WTP) for a hypothetical Ebola vaccine in Indonesia. Methods: A cross-sectional study was conducted from 1 August to 30 December 2015 in five cities in Aceh province of Indonesia. Patients' family members who visited outpatient departments were approached and interviewed about their sociodemographic characteristics, knowledge of Ebola, attitude towards vaccination practice and their WTP for a hypothetical Ebola vaccine. A multivariable linear regression model assessed the relationship between these explanatory variables and WTP. Results: During the study, 500 participants were approached and interviewed. There were 424 (84.8%) respondents who completed the interview and 74% (311/424) expressed their acceptance for an Ebola vaccine. There were 288 participants who were willing to pay for an Ebola vaccine (92.6% out of 311). The mean of WTP was US$2.08 (95% CI: 1.75-2.42). The final multivariable model indicated that young age, high educational attainment, working as a private employee, entrepreneur or civil servant (compared to farmers), being unmarried, and residing in a suburb (compared to a city) were associated with higher WTP. Conclusions: Although the proportion of the participants who would accept the Ebola vaccine was relatively high, the amount they were willing to pay for Ebola vaccine was very low. This finding would indicate the need of subsidies for Ebola vaccine in the country.

Willingness-to-pay for a hypothetical Ebola vaccine in Indonesia: A cross-sectional study in Aceh

Background: Some Ebola vaccines have been developed and tested in phase III clinical trials. However, assessment of whether public have willingness to purchase or not, especially in unaffected areas, is lacking. The aim of this study was to determine willingness to pay (WTP) for a hypothetical Ebola vaccine in Indonesia. Methods: A cross-sectional study was conducted from 1 August to 30 December 2015 in five cities in Aceh province of Indonesia. Patients' family members who visited outpatient departments were approached and interviewed about their sociodemographic characteristics, knowledge of Ebola, attitude towards vaccination practice and their WTP for a hypothetical Ebola vaccine. A multivariable linear regression model assessed the relationship between these explanatory variables and WTP. Results: During the study, 500 participants were approached and interviewed. There were 424 (84.8%) respondents who completed the interview and 74% (311/424) expressed their acceptance for an Ebola vaccine. There were 288 participants who were willing to pay for an Ebola vaccine (92.6% out of 311). The mean of WTP was US$2.08 (95% CI: 1.75-2.42). The final multivariable model indicated that young age, high educational attainment, working as a private employee, entrepreneur or civil servant (compared to farmers), being unmarried, and residing in a suburb (compared to a city) were associated with higher WTP. Conclusions: Although the proportion of the participants who would accept the Ebola vaccine was relatively high, the amount they were willing to pay for Ebola vaccine was very low. This finding would indicate the need of subsidies for Ebola vaccine in the country.

Willingness to pay for hepatitis B vaccination in Selangor, Malaysia: A cross-sectional household survey

Background

In Malaysia, one million individuals are estimated to be infected with the hepatitis B virus. A vaccine for infants has been compulsory since 1989, whereas those born before 1989 need to spend their own money to be vaccinated in private clinics or hospitals. The aim of this study was to investigate and ascertain the determinants of willingness to pay (WTP) for adult hepatitis B vaccine in Selangor, Malaysia.

Methods

In 2016, 728 households were selected through a stratified, two stage cluster sample and interviewed. Willingness to pay for hepatitis B vaccine was estimated using the Contingent Valuation Method, and factors affecting WTP were modelled with logit regression.

Results

We found that 273 (37.5%) of the households were willing to pay for hepatitis B vaccination. The mean and median of WTP was estimated at Ringgit Malaysia (RM)303 (approximately US$73) for the three dose series. The estimated WTP was significantly greater in those with higher levels of education, among Malays and Chinese (compared to others, predominantly Indians), and for those with greater perceived susceptibility to hepatitis B virus infection. Other factors–perceived severity, barriers, benefits and cues to action–were not significantly associated with WTP for adult hepatitis B vaccination.

Conclusion

Additional resources are needed to cover the households that are not willing to pay for hepatitis B vaccination. More awareness (particularly in regards to hepatitis B virus susceptibility) could change the national perception towards self-paid hepatitis B virus vaccination and increase hepatitis B vaccine coverage.

Community acceptance and willingness-to-pay for a hypothetical Zika vaccine: A cross-sectional study in Indonesia

BACKGROUND

Understanding people's perceptions of the economic benefits of a potential Zika vaccine (ZV) is critical to accelerating its introduction into either public sector programs or private market. The aim of this study was to assess the acceptance and willingness-to-pay (WTP) for a hypothetical ZV and the associated explanatory variables in Indonesia.

METHODS

We conducted a health facility-based cross-sectional study in Aceh and West Sumatra province from 1 February to 13 June 2018. Patients who visited outpatient departments, have had children or were expecting their first child, were approached and interviewed to collect information on acceptance, WTP, demographic and socio-economic variables and attitudes towards childhood vaccines. Associations of explanatory variables influencing acceptance and WTP were assessed using logistic regression and linear regression analysis, respectively.

RESULTS

In total, 956 respondents were included in the final analysis of acceptance, of whom 338 (35.3%) expressed their WTP. We found that 757 (79.1%) of the respondents were likely to be vaccinated and to recommend their partner to be vaccinated. Higher educational attainment, having a job, having heard about Zika and a good attitude towards childhood vaccination were associated with ZV acceptance in the univariate analyses. In the multivariate analysis, attitude towards childhood vaccination was the strongest predictor for ZV vaccination. We found the geometric mean and median of WTP was US$ 13.1 (95% CI: 11.37-15.09) and US$ 7.0 (95% CI: 4.47-10.98), respectively. In the final model, having heard about Zika, having a job, and higher income were associated with a higher WTP.

CONCLUSION

Although the acceptance rate of the ZV is relatively high in Indonesia, less than 40% of respondents are willing to pay, underscoring the need for a low-cost, high-quality vaccine and public sector subsidies for Zika vaccinations in the country.

Customers' preferences and willingness to pay for a future dengue vaccination: a study of the empirical evidence in Vietnam

BACKGROUND

Dengue was endemic to Vietnam. Due to the lack of a readily available remedy, dengue vaccines (DV) have been used elsewhere to cure the disease. However, introducing DV in Vietnam has met resistance from society and the government, influencing decisions about willingness-to-pay (WTP) and other pharmacoeconomic studies. This research aimed to evaluate the extent to which Vietnamese customers would be willing to pay to vaccinate themselves and their children, if any at all, against dengue.

MATERIALS AND METHODS

This was a cross-sectional interview-based research. Contingent valuation method, combined with the bidding technique and several open-ended questions, were used to obtain the maximum WTP values for six hypothetical scenarios of two types of DV (60% efficacy for 10 years, "Type 1" vs 90% efficacy for 20 years, "Type 2").

RESULTS

The median WTP per adult for Type 1 and Type 2 DV were US$130.34 and US$217.39, respectively. The median WTP rates per parent for their own vaccination were US$86.96 (Type 1) and US$156.52 (Type 2), for their children vaccination costs were US$108.70 (Type 1) and US$195.65 (Type 2). Five factors affected the WTP rates: monthly income, marital status, area, locality and level of education.

CONCLUSION

The WTP rates for DV were high, supporting the introduction of DV in Vietnam.

The acceptance and willingness to pay (WTP) for hypothetical dengue vaccine in Penang, Malaysia: a contingent valuation study

BACKGROUND

Malaysia has been experiencing an escalation in dengue cases since the past 5 years. As the dengue vaccine pipeline continues to develop steadily with strong public interests, this study had been sought to elicit the acceptance and the willingness to pay (WTP) for hypothetical dengue vaccine in Malaysia.

METHODS

This study adopted the cross-sectional, contingent valuation study that involved 400 respondents in Penang, Malaysia. The double-bounded dichotomous choice via bidding game approach was employed to elicit the WTP value for two hypothetical 3-doses dengue vaccines (Vaccines A and B with 5- and 10-years' protection, respectively against dengue). A univariate logistic regression model was employed to assess the key determinants of vaccine acceptance, while the mean WTP value and its associated factors were measured by using the parametric two-part model (TPM).

RESULTS

Dengue vaccine appeared to be highly acceptable (88.4%) among the population in Penang, Malaysia. Respondents who were of Chinese ethnicity (OR 0.36, p = 0.017), with higher dengue knowledge score (OR 1.43, p = 0.016), and higher vaccination attitude score (OR 1.91, p < 0.001) were more likely to accept the vaccine. The first step logit estimation from TPM displayed that pensioners (OR 2.37, p = 0.036), respondents who were self-employed or working in the private sector (OR 1.21, p = 0.002), respondents with higher education level (OR 2.09-3.29, p < 0.05), and those who accepted the vaccine (OR 3.23, p = 0.001) were more likely to pay for the vaccine. The adjusted mean WTP value for the vaccine was MYR39.21 (USD9.45) per dose. Next, the second-stage regression from TPM revealed the key factors that significantly affected the WTP value, which were composed of age, gender, occupation, household income, dengue prevention practice, and protection duration of the vaccine. The pensioners and those with better dengue prevention practice were willing to pay more for the vaccines. Additionally, all the respondents elicited a higher WTP amount toward the vaccine with longer protection duration (Vaccine B).

CONCLUSION

Strong acceptance toward dengue vaccine reflects the high value of the vaccine in Malaysia. The WTP estimates offer quantification of the private benefit in reducing occurrences of the disease. Besides, the people's preferences-based WTP value for the vaccine tends to complement scientific decision-making and prioritization in the management of dengue in the country.

Vaccine Demand and Willingness-to-pay for Arbovirus Vaccines: A Cross-sectional Survey in Rural Guatemala

BACKGROUND

Arboviruses including dengue (DENV), chikungunya (CHIKV) and Zika cause significant morbidity in Latin America. With multiple arbovirus vaccines in development, better understanding of community attitudes and acceptability for these vaccines is needed.

METHODS

In September 2016, a cross-sectional survey assessed arbovirus knowledge, attitudes, vaccine demand and willingness-to-pay (WTP) at the conclusion of a DENV/norovirus surveillance study in rural Guatemala with high arbovirus endemicity. Factors associated with vaccine demand and WTP were assessed with regression analysis.

RESULTS

Among 564 surveyed households, DENV knowledge was high. There was great concern for arboviruses, particularly CHIKV. Overall vaccine attitudes were positive with <5% identifying significant barriers, hesitancy or refusing previous vaccination. At 50% and 75% efficacy, 75% and 88% of respondents wanted arbovirus vaccines, respectively. DENV vaccine demand at 50% efficacy was associated with increased housing density, nonhealth postvaccination location, older children and medical source for information. For each vaccine, 52-55% of respondents were WTP $0-$3.40, while 16-17% were WTP ≥$6.81. WTP at $3.40 and $6.81 levels for all vaccines was associated positively with parental education but negatively with good DENV knowledge. History of purchasing and identifying barriers to vaccines was associated with WTP ≥$6.81.

CONCLUSIONS

Demand for potential DENV, CHIKV and Zika vaccines is high at 50% and 75% efficacy in this Guatemalan community. Associated factors could be leveraged to optimize arbovirus vaccine implementation. Overall low WTP given current cost of Dengvaxia (Sanofi Pasteur, Lyon, France) suggests that government subsidization may be necessary in resource-poor regions, though a small private market may be supported.

Knowledge, attitude, and practice regarding dengue virus infection among inhabitants of Aceh, Indonesia: a cross-sectional study

BACKGROUND

The Indonesian region of Aceh was the area most severely affected by the earthquake and tsunami of 26 December 2004. Department of Health data reveal an upward trend of dengue cases in Aceh since the events of the tsunami. Despite the increasing incidence of dengue in the region, there is limited understanding of dengue among the general population of Aceh. The aim of this study was to assess the knowledge, attitude, and practice (KAP) regarding dengue among the people of Aceh, Indonesia in order to design intervention strategies for an effective dengue prevention program.

METHODS

A community-based cross-sectional study was conducted in Aceh between November 2014 and March 2015 with a total of 609 participants living in seven regencies and two municipalities. Information on the socio-demographic characteristics of participants and their KAP regarding dengue was collected using a pre-tested structured questionnaire. The KAP status (good vs. poor) of participants with different socio-demographic characteristics was compared using Chi Square-test, ANOVA or Fisher's exact test as appropriate. Logistic regression analysis was used to determine the predictors of each KAP domain.

RESULTS

We found that 45% of participants had good knowledge regarding dengue and only 32% had good attitudes and good dengue preventive practices. There was a significant positive correlation between knowledge and attitudes, knowledge and practice, and attitudes and practice. In addition, people who had good knowledge were 2.7 times more likely to have good attitudes, and people who had good attitudes were 2.2 times more likely to have good practices regarding dengue. The level of education, occupation, marital status, monthly income, socioeconomic status (SES) and living in the city were associated with the knowledge level. Occupation, SES, and having experienced dengue fever were associated with attitudes. Education, occupation, SES and type of residence were associated with preventive practices.

CONCLUSION

Our study suggests that dengue prevention programs are required to increase KAP levels regarding dengue in the communities of Aceh.

Willingness to pay for an Ebola vaccine during the 2014-2016 ebola outbreak in West Africa: Results from a U.S. National sample

The 2014-2016 Ebola virus outbreak in West Africa led to advances in the development of vaccines against Ebola. This study examined factors associated with willingness to pay for an Ebola vaccine among a U.S. national sample during the recent Ebola outbreak. From April 30-May 8, 2015, a national survey was conducted using the GfK Group's KnowlegePanel®. Main outcome measures included willingness to pay at least $1; more than $50; and more than $100 for an Ebola vaccine. Analyses were conducted using weighted multivariable logistic regression. Among participants (N = 1,447), 583 (40.3%) would not pay for an Ebola vaccine; 864 (59.7%) would pay at least $1. Among those willing to pay at least $1: 570 (66.0%) would pay $1-50; 174 (20.1%) would pay $51-100; and 120 (13.9%) would pay more than $100. Willingness to pay at least $1 for an Ebola vaccine was associated with international travel; interest in getting an Ebola vaccine; and beliefs that the U.S. government should spend money to control Ebola and assume worldwide leadership in confronting emerging epidemics. Willingness to pay more than $50 was associated with similar variables. Willingness to pay more than $100 was associated with international travel; interest in getting an Ebola vaccine; information seeking; and beliefs that the U.S. government should assume worldwide leadership in confronting emerging epidemics. International travel and interest in an Ebola vaccine were key predictors of willingness to pay across all price points. Understanding willingness to pay for vaccines against emerging infectious diseases remains critical.

Feasibility and willingness to pay for dengue vaccine in the threat of dengue fever outbreaks in Vietnam

BACKGROUND

The escalation of dengue fever (DF) cases in recent years and the occurrence of a large-scale DF outbreak in 2017 underline the importance of dengue vaccines in Vietnam. Given the potential benefits of the dengue vaccines and the need for copayment by the private sector, this study aims to evaluate the willingness to pay (WTP) for the dengue vaccines in patients with DF in Northern Vietnam.

METHODS

A cross-sectional study was conducted on 330 in-and-out patients with DF admitted to the Bach Mai Hospital. We used the contingent valuation method to evaluate the WTP for dengue vaccines. Socioeconomic and clinical characteristics were also investigated. Multivariate interval and logistic regression models were used to estimate the average amount of WTP and identify the factors associated with the WTP.

RESULTS

Around 77.3% patients were willing to pay an average amount of US$ 67.4 (95% CI=57.4-77.4) for the vaccine. People of higher ages, those having health insurance, those traveling in the past 15 days or suffering from anxiety/depression were less likely to be willing to pay for the dengue vaccine. However, people having a longer duration of DF or having problems with mobility were positively associated with WTP for the dengue vaccine. Patients educated to more than high school levels (Coeff.=31.31; 95% CI=3.26-59.35), those in the richest quintile (Coeff.=62.76; 95% CI=25.40; 100.13), or those having a longer duration of the disease (Coeff.=6.18; 95% CI=0.72-11.63) were willing to pay a higher amount.

CONCLUSION

This study highlights a relatively high rate and amount of WTP for the dengue vaccine among patients with DF. Psychological counseling services as well as educational campaigns should be undertaken to improve the WTP for the vaccine. Moreover, government subsidies should be given to increase the coverage of the vaccine in the future, especially for the poor.

Outdoor spatial spraying against dengue: A false sense of security among inhabitants of Hermosillo, Mexico

Background

Government-administered adulticiding is frequently conducted in response to dengue transmission worldwide. Anecdotal evidence suggests that spraying may create a “false sense of security” for residents. Our objective was to determine if there was an association between residents’ reporting outdoor spatial insecticide spraying as way to prevent dengue transmission and both their reported frequency of dengue prevention practices and household entomological indices in Hermosillo, Mexico.

Methodology/Principal findings

A non-probabilistic survey of 400 households was conducted in August 2014. An oral questionnaire was administered to an adult resident and the outer premises of the home were inspected for water-holding containers and presence of Ae. aegypti larvae and pupae. Self-reported frequency of prevention practices were assessed among residents who reported outdoor spatial spraying as a strategy to prevent dengue (n = 93) and those who did not (n = 307). Mixed effects negative binomial regression was used to assess associations between resident’s reporting spraying as a means to prevent dengue and container indices. Mixed effects logistic regression was used to determine associations with presence/absence of larvae and pupae. Those reporting spatial spraying disposed of trash less frequently and spent less time indoors to avoid mosquitoes. They also used insecticides and larvicides more often and covered their water containers more frequently. Their backyards had more containers positive for Ae. aegypti (RR = 1.92) and there was a higher probability of finding one or more Ae. aegypti pupae (OR = 2.20). Survey respondents that reported spatial spraying prevented dengue were more likely to be older and were exposed to fewer media sources regarding prevention.

Conclusions/Significance

The results suggest that the perception that outdoor spatial spraying prevents dengue is associated with lower adoption of prevention practices and higher entomological risk. This provides some support to the hypothesis that spraying may lead to a “false sense of security”. Further investigations to clarify this relationship should be conducted. Government campaigns should emphasize the difficulty in controlling Ae. aegypti mosquitoes and the need for both government and community action to minimize risk of dengue transmission.

Outdoor spatial spraying is commonly practiced by local governments as a prevention strategy for dengue and other Aedes-borne viruses. However, it has been publically criticized for its potential to reduce community-level actions such as clearance of mosquito habitat due to a resulting “false sense of security”. This study uses a paired social and entomological survey to analyze the association between residents’ perception that outdoor spraying prevents dengue and household level dengue fever prevention practices and entomological indicators in a city in northern Mexico. Our results suggest that those who view dengue is prevented by outdoor spatial spraying had 1) lower frequencies of elimination of potential mosquito breeding sites and higher frequencies of exposure to the vector, 2) higher entomological risk, and 3) a different socio-demographic profile than those who did not report it as effective. Our findings support the possibility that outdoor space spraying may lead to a “false sense of security” which reduces household engagement in prevention activities.

Determinants of felt demand for dengue vaccines in the North Caribbean region of Colombia

BACKGROUND

The increasing burden associated with dengue in Latin America makes it essential to understand the community's interest in acquiring vaccines, as an input to plan its introduction in endemic regions. The objective of this study is to learn the felt demand for dengue vaccines by estimating the willingness to pay and its associated factors in endemic communities of the North Caribbean region of Colombia.

METHODS

A population survey was administered from October to December 2015, including 1037 families in 11 municipalities in Colombia. One adult per family was interviewed on their perception and history of dengue. Participants received a description of four hypothetical scenarios of dengue vaccines, administered in a single dose or in 3 doses, with an effectiveness of 70% for 5 years or 95% for 30 years. The willingness to pay for each one of these vaccines was inquired vs. 5 hypothetical prices in Colombian pesos.

RESULTS

Most participants recognized dengue as a serious disease in children (99.3%) and adults (98.6%). 33 (3.2%) of the total respondents reported having suffered dengue and 19 (57.6%) of them required hospitalization. The price of the vaccine was inversely related to the willingness to pay. In addition, single dose vaccines (compared to 3 doses) and one with a protection of 95% for 30 years (compared to an effectiveness of 70% for 5 years), were associated with greater willingness to pay. Greater willingness to pay was observed among the respondents who considered it likely to get the disease, either themselves (OR 1.56; CI 95% 1.08-2.26) or their children (OR 1.89; CI 95% 1.28-2.81), in the next 5 years. The participants who have been diagnosed with dengue also showed greater willingness to pay (OR 1.89; CI 95% 1.01-3.54) compared to those who did not have this history.

CONCLUSION

Factors such as price, number of doses and effectiveness can independently influence the decision to purchase a vaccine against an endemic disease, such as dengue. Additionally, this study reveals that background and perceptions of the disease can affect individuals' interest in acquiring this type of preventive interventions.

Consumer Willingness to Pay for Dengue Vaccine (CYD-TDV, Dengvaxia®) in Brazil; Implications for Future Pricing Considerations

Introduction and Objective: Dengue virus is a serious global health problem with an estimated 3.97 billion people at risk for infection worldwide. In December 2015, the first vaccine (CYD-TDV) for dengue prevention was approved in Brazil, developed by Sanofi Pasteur. However, given that the vaccine will potentially be paid via the public health system, information is need regarding consumers' willingness to pay for the dengue vaccine in the country as well as discussions related to the possible inclusion of this vaccine into the public health system. This was the objective of this research. Methods: We conducted a cross-sectional study with residents of Greater Belo Horizonte, Minas Gerais, about their willingness to pay for the CYD-TDV vaccine. Results: 507 individuals were interviewed. These were mostly female (62.4%) had completed high school (62.17%), were working (74.4%), had private health insurance (64.5%) and did not have dengue (67.4%). The maximum median value of consumers' willingness to pay for CYD-TDV vaccine is US$33.61 (120.00BRL) for the complete schedule and US$11.20 (40.00BRL) per dose. At the price determined by the Brazil's regulatory chamber of pharmaceutical products market for the commercialization of Dengvaxia® for three doses, only 17% of the population expressed willingness to pay for this vaccine. Conclusion: Brazil is currently one of the largest markets for dengue vaccine and the price established is a key issue. We believe the manufacturer should asses the possibility of lower prices to reach a larger audience among the Brazilian population.

Willingness to pay for a dengue vaccine and its associated determinants in Indonesia: A community-based, cross-sectional survey in Aceh

Vaccination strategies are being considered as a part of dengue prevention programs in endemic countries. To accelerate the introduction of dengue vaccine into the public sector program and private markets, understanding the private economic benefits of a dengue vaccine is therefore essential. The aim of this study was to assess the willingness to pay (WTP) for a dengue vaccine among community members in Indonesia and its associated explanatory variables. A community-based, cross-sectional survey was conducted in nine regencies of Aceh province, Indonesia, from November 2014 to March 2015. A pre-tested validated questionnaire was used to facilitate the interviews. To assess the explanatory variables influencing participants' WTP for a dengue vaccine, a linear regression analysis was employed. We interviewed 677 healthy community members; 476 participants (87.5% of the total) were included in the final analysis. An average individual was willing to pay around US-$ 4 (mean: US-$ 4.04; median: US-$ 3.97) for a dengue vaccine. Our final multivariate model revealed that working as a civil servant, living in the city, and having good knowledge on dengue viruses, a good attitude towards dengue, and good preventive practice against dengue virus infection were associated with a higher WTP (P<0.05). Our model suggests that marketing efforts should be directed to community members who are working in the suburbs especially as farmers. In addition, the results of our study underscore the need for low-cost quality vaccines, public sector subsidies for vaccinations, and intensifying efforts to further educate and encourage households regarding other dengue preventive measures, using trusted individuals as facilitators.

The economic promise of developing and implementing dengue vaccines: Evidence from a systematic review

BACKGROUND

Dengue fever is one of the most rapidly advancing viral vector-borne diseases worldwide and vaccine candidates are in the final stages of clinical trials, representing a decisive opportunity to control the disease. To decide whether and where to support the introduction of new vaccines it is crucial to assess costs imposed by the disease and cost-effectiveness of vaccine programmes.

OBJECTIVE

To identify economic evidence about dengue fever immunization, by systematic review, to assist future policy decisions and investment.

METHODS

The electronic search stage was conducted on PubMed/Medline, Embase, Web of Science, Global Health, NHS Economic Evaluation Database (NHS EED) and Latin American and Caribbean Health Sciences Literature (LILACS) databases. Searches were restricted to papers published between January 1970 and February 2016. Selected papers were quality assessed using three recognized checklists.

RESULTS

Eleven relevant studies were identified and there is economic evidence of a satisfactory quality level, derived through modelling approaches, to conclude that dengue fever vaccines will be economically advantageous when compared to vector preventive strategies, despite uncertainties surrounding vaccine efficacy and costs per vaccine dose. Quality assessment based on checklists showed similar findings and although overall quality was considered satisfactory, there were relevant methodological issues not considered among studies reviewed.

CONCLUSION

Several uncertainties still remain about effectiveness of dengue fever vaccines; however, the reviewed economic evidence suggests that, when available, the vaccine can be economically advantageous at moderate prices. Future research needs to confirm findings from the economic models by using actual costs and effectiveness data.

Dengue vaccine acceptance and willingness to pay

The introduction of new vaccines is accompanied by a variety of challenges. Among these, very important ones concern the questions whether the public is willing to accept and willing to purchase the vaccine. Here we discuss factors associated with these questions in the context of vaccines that are becoming available against dengue virus infection. We reviewed published studies available from PubMed and Embase, conducting a meta-analysis when possible and narrative review when the data did not qualify for meta-analysis. We found that attitude toward vaccination and socioeconomic level had significant associations with dengue vaccine acceptance. In addition, socioeconomic level, knowledge, attitude and practice regarding dengue fever, having personally experienced dengue fever and vaccine price were associated with willingness to pay for dengue vaccine. To improve acceptance and willingness to pay for dengue vaccine, well-designed introduction programs that address the associated factors in a context-specific manner are essential.

Modifiable determinants of attitude towards dengue vaccination among healthy inhabitants of Aceh, Indonesia: Findings from a community-based survey

OBJECTIVE

To explore and understand the attitude towards dengue vaccination and its modifiable determinants among inhabitants of Aceh (northern Sumatra Island, Indonesia), the region that was most severely affected by the earthquake and tsunami of 26 December 2004.

METHODS

A community-based, cross-sectional study was conducted among 535 healthy inhabitants in nine regencies (Kabupaten or Kotamadya) of Aceh that were selected randomly from November 2014 to March 2015. A set of validated, pre-tested, structured questionnaires was used to guide the interviews. The questionnaires covered a range of explanatory variables and one outcome variable (attitude to dengue vaccination). Multi-step logistic regression analysis and Spearman's rank correlation were used to test the role of explanatory variables for the outcome variable.

RESULTS

More than 70% of the participants had a poor attitude towards dengue vaccination. Modifiable determinants associated with poor attitude to dengue vaccination were low education level, working as farmers and traditional market traders, low socioeconomic status and poor knowledge, attitude and practice regarding dengue fever (P < 0.05). The KAP domain scores were correlated strongly with attitude to dengue vaccination, rs = 0.25, rs = 0.67 and rs = 0.20, respectively (P < 0.001). Multivariate analysis found that independent predictors associated with attitude towards dengue vaccination among study participants were only sex and attitude towards dengue fever (P < 0.001).

CONCLUSIONS

This study reveals that low KAP regarding dengue fever, low education level and low socioeconomic status are associated with a poor attitude towards dengue vaccination. Therefore, inhabitants of suburbs who are working as farmers or traditional market traders with low socioeconomic status are the most appropriate target group for a dengue vaccine introduction program.

Community Willingness to Participate in a Dengue Study in Aceh Province, Indonesia

BACKGROUND

Dengue virus infection is the most rapidly spreading vector-borne disease in the world. Essential research on dengue virus transmission and its prevention requires community participation. Therefore, it is crucial to understand the factors that are associated with the willingness of communities in high prevalence areas to participate in dengue research. The aim of this study was to explore factors associated with the willingness of healthy community members in Aceh province, Indonesia, to participate in dengue research that would require phlebotomy.

METHODOLOGY/PRINCIPAL FINDINGS

A community-based cross-sectional study was carried out in nine regencies and municipalities of Aceh from November 2014 to March 2015. Interviews using a set of validated questionnaires were conducted to collect data on demography, history of dengue infection, socioeconomic status, and knowledge, attitude and practice regarding dengue fever. Two-step logistic regression and Spearman's rank correlation (rs) analysis were used to assess the influence of independent variables on dependent variables. Among 535 participants, less than 20% had a good willingness to participate in the dengue study. The factors associated with good willingness to participate were being female, working as a civil servant, private employee or entrepreneur, having a high socioeconomic status and good knowledge, attitude and practice regarding dengue. Good knowledge and attitude regarding dengue were positive independent predictors of willingness to participate (OR: 2.30 [95% CI: 1.36-3.90] and 3.73 [95% CI: 2.24-6.21], respectively).

CONCLUSION/SIGNIFICANCE

The willingness to participate in dengue research is very low among community members in Aceh, and the two most important associated factors are knowledge and attitude regarding dengue. To increase participation rate, efforts to improve the knowledge and attitude of community members regarding dengue fever and dengue-related research is required before such studies are launched.

Health-Care Workers' Perspectives on Ebola Virus Vaccine: A Focus Group and In-Depth Interview Interventional Study

Health-care workers (HCWs) will require Ebola virus vaccine (EVV) when it is introduced because of the high risk of exposure to the disease. Evaluations of factors that facilitate or limit vaccine uptake are critical for a successful vaccine program. Nigerian HCWs were interviewed to evaluate their knowledge, levels of acceptance, determinants of acceptance, and willingness to pay for EVV. The significance level was set at P ≤ 0.05. None of the 193 participating HCWs had correct knowledge of EVV; 34.7% (67/193) of workers thought that EVV was an extract of the serum of Ebola virus patients. About 77.3% (51/66) of workers in a region that reported Ebola cases (Lagos) were willing to be vaccinated, compared with 4.7% (3/61) in Enugu and 13.6% (9/66) in Abia (P = 0.0001). After health education, the proportion of HCWs willing to receive EVV increased (P = 0.006) except for doctors (P < 0.1). The percentage of HCWs willing to pay for EVV was 86.4%, 72.1%, and 59% in Lagos, Enugu, and Abia, respectively. The workers had fears about EVV based on nonfactual assumptions. Therefore, the EVV introduction strategy should include a strong awareness campaign with adequate explanation about the content of EVV.