Vaccine HesitancyNCT06418854
Dengue Vaccine Hesitancy Among International Travelers
A study testing Questionnaire in people with Vaccine Hesitancy, run by Mahidol University at 1 site in Thailand.
Trial summary
The goal of this cross-sectional study is to study dengue vaccine hesitancy among 390 international travelers who visit the Hospital for Tropical Diseases, Bangkok, and three public sites which are the area near the Grand Palace, Khaosan Road, and the snake farm at Queen Saovabha Memorial Institute. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Vaccine Hesitancy
- What is being tested?
- Questionnaire
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 390 participants
- Where
- 1 siteThailand
- Study dates
- 1 Jun 2024to 31 Dec 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Male and female international travelers from dengue-non-endemic countries
- Age ≥18 years old
- Able to read and understand English questionnaire
- Willing to participate in the study Endemic countries of dengue will be defined as all countries in the ASEAN(Association of Southeast Asian Nations) economic community countries, Central and South American countries except Chile, and ten countries in Eastern Mediterranean and Africa showing high frequency of dengue transmission according to WHO(World Health Organization) and ECDC(European Centre for Disease Prevention and Control) data(Yemen, Egypt, Sudan, Eritrea, Djibouti, Tanzania, Kenya, Ethiopia, Somalia, Burkina Faso). Non-endemic countries refer to all the other countries apart from endemic countries.
Who cannot join
- Travelers who are visiting the hospital for dengue vaccination or dengue infection or dengue-like symptoms, which is defined as acute fever with one of the following; rash, myalgia, headache, nausea, vomiting, retro-orbital pain.
- Participants who are expatriate workers or lived in Thailand or other Southeast Asia countries for more than 1 year.
Trial locations and contacts
1 site in 1 country.
About this study
The goal of this cross-sectional study is to study dengue vaccine hesitancy among 390 international travelers who visit the Hospital for Tropical Diseases, Bangkok, and three public sites which are the area near the Grand Palace, Khaosan Road, and the snake farm at Queen Saovabha Memorial Institute. The main question it aims to answer is what are the factors associated with the dengue vaccine hesitancy among non-endemic international travelers visiting Thailand.
Participants will do the questionnaire consists of three parts
- Questionnaire to estimate vaccine hesitancy on each 5 domains.
- Knowledge about dengue infection and vaccination
- Demographics data of the participants The study prioritizes ethical considerations, confidentiality, and data management to ensure participant welfare and data security.
Read the detailed description
Rationale:
Dengue, a disease caused by the flavivirus and characterized by four distinct serotypes, stands as a substantial public health concern, with an estimated 390 million infections occurring worldwide annually. Clinical manifestations range from mild febrile illness to severe dengue, with secondary infections carrying a heightened risk due to antibody-dependent enhancement (ADE). The incidence of dengue among travelers to endemic areas is around one percent monthly, influenced by factors like exposure duration, seasonality, and traveler activities. Despite lacking a specific treatment, vaccination has emerged as a promising preventative measure. However, the initial vaccines licensed in the market have demonstrated limited efficacy. Vaccination in a naïve population has been associated with an increased likelihood of severe disease during the initial natural dengue infection. The recently licensed second dengue vaccine requires further information before comprehensive guidelines for usage in travelers can be established.
The rise of vaccine hesitancy, marked by reluctance or refusal, poses a growing concern, potentially leading to low vaccine coverage and emerging outbreaks. The literature about dengue vaccine hesitancy is very scarce because, unlike measles or COVID-19(CoronaVirus Disease of 2019), the efficacy of the dengue vaccine does not prove itself as a highly recommended option to prevent the disease. However, the controversial incident with the first dengue vaccine seemed to embed significant hesitation in both dengue and other vaccinations as well. Furthermore, proactive preparation for the prospective integration of the dengue vaccine into the national immunization program or its designation as a recommended vaccine for travelers is also crucial. This research aims to determine dengue vaccine hesitancy and its associated factors among non-endemic international travelers visiting Thailand, providing valuable insights for future vaccine recommendations and discussions.
Objectives:
- To study the dengue vaccine hesitancy among non-endemic international travelers visiting Thailand.
- To assess the factors associated with the dengue vaccine hesitancy among non-endemic international travelers visiting Thailand.
Methodology:
The cross-sectional study will recruit 390 international travelers who visit the Hospital for Tropical Diseases, Bangkok, and three public sites which are the area near the Grand Palace, Khaosan Road, and the snake farm at Queen Saovabha Memorial Institute. Data collection involves a one-time gathering of information, with eligible participants willing to provide informed consent. The questionnaire can be done both paper-based and online-based (JOTFORM), which takes time around 10-15 minutes. The questionnaire consists of 3 main parts including, a question assessing dengue vaccine hesitancy, knowledge about dengue vaccination, and demographic data. The questionnaire for estimating dengue vaccine hesitancy was derived from previous literature and validated with the pilot cohort of 20 participants. The study prioritizes ethical considerations, confidentiality, and data management to ensure participant welfare and data security.
- Conditions
- Vaccine Hesitancy
- Being tested
- Questionnaire
- Keywords
- Dengue vaccine hesitancy, International travelers, 5C(Confidence, Complacency, Constraints, Risk calculation, Collective responsibility) model
- Medical subject headings
- Vaccination Hesitancy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
QuestionnaireOther
Adapted design questionnaire to estimate the vaccine hesitancy specifically for dengue vaccine
| Study group | Role | What they receive |
|---|---|---|
| Non-endemic international travelers | Experimental | Not described Receives: Other: Questionnaire |
What is being measured
The primary outcome is the main question the study is designed to answer.
Dengue vaccine hesitancy score
Spectrum of the dengue vaccine hesitancy score will be assessed by the 15 items questionaire with 7 likert scales adapting from 5C determinants of the vaccine hesitancy. The score ranging from 3-45 for each 5 domains. Higher score will represent stronger impact for each determinants; the positive determinants are confidence and collective responsibility while negative determinants are constraints, complacency, and calculation.
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 May 2024
- Study start1 Jun 2024
- Primary completion1 Nov 2024
- Study completion31 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Vaccine HesitancyStudies of the same condition, open and under way.
- More trials run by Mahidol UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 390 participants (actual)
Sponsor and investigators
- Lead sponsor
- Mahidol University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Thundon Ngamprasertchai, MD, Mahidol University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06418854
- Sponsor's protocol ID
- MUTM-2024-030-01
- Status last verified
- Jan 2025
- First submitted
- 8 May 2024
- Last updated
- 9 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Charoenwisedsil R, Lawpoolsri S, Rattanaumpawan P, Ruenroengbun N, Flaherty GT, Parker DM, Ngamprasertchai T. Barriers to dengue vaccine uptake in international travelers: a mixed-methods study. Expert Rev Vaccines. 2026 Dec;25(1):2689612. doi: 10.1080/14760584.2026.2689612. Epub 2026 Jun 21.
PubMed 42289086
Study at a glance
From the registry record, last updated by the sponsor on 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Dengue Vaccine Hesitancy Among International Travelers
- ClinicalTrials.gov ID
- NCT06418854
- Acronym / sponsor ID
- MUTM-2024-030-01
- Conditions
- Vaccine Hesitancy
- Keywords
- Dengue vaccine hesitancy, International travelers, 5C(Confidence, Complacency, Constraints, Risk calculation, Collective responsibility) model
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 390 participants (actual)
- Lead sponsor
- Mahidol UniversityUniversity, hospital or other
- Study start
- 1 Jun 2024 (actual)
- Primary completion
- 1 Nov 2024 (actual)
- Study completion
- 31 Dec 2024 (actual)
- First posted
- 17 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this cross-sectional study is to study dengue vaccine hesitancy among 390 international travelers who visit the Hospital for Tropical Diseases, Bangkok, and three public sites which are the area near the Grand Palace, Khaosan Road, and the snake farm at Queen Saovabha Memorial Institute. The main question it aims to answer is what are the factors associated with the dengue vaccine hesitancy among non-endemic international travelers visiting Thailand.
Participants will do the questionnaire consists of three parts
- Questionnaire to estimate vaccine hesitancy on each 5 domains.
- Knowledge about dengue infection and vaccination
- Demographics data of the participants The study prioritizes ethical considerations, confidentiality, and data management to ensure participant welfare and data security.
Detailed description
Rationale:
Dengue, a disease caused by the flavivirus and characterized by four distinct serotypes, stands as a substantial public health concern, with an estimated 390 million infections occurring worldwide annually. Clinical manifestations range from mild febrile illness to severe dengue, with secondary infections carrying a heightened risk due to antibody-dependent enhancement (ADE). The incidence of dengue among travelers to endemic areas is around one percent monthly, influenced by factors like exposure duration, seasonality, and traveler activities. Despite lacking a specific treatment, vaccination has emerged as a promising preventative measure. However, the initial vaccines licensed in the market have demonstrated limited efficacy. Vaccination in a naïve population has been associated with an increased likelihood of severe disease during the initial natural dengue infection. The recently licensed second dengue vaccine requires further information before comprehensive guidelines for usage in travelers can be established.
The rise of vaccine hesitancy, marked by reluctance or refusal, poses a growing concern, potentially leading to low vaccine coverage and emerging outbreaks. The literature about dengue vaccine hesitancy is very scarce because, unlike measles or COVID-19(CoronaVirus Disease of 2019), the efficacy of the dengue vaccine does not prove itself as a highly recommended option to prevent the disease. However, the controversial incident with the first dengue vaccine seemed to embed significant hesitation in both dengue and other vaccinations as well. Furthermore, proactive preparation for the prospective integration of the dengue vaccine into the national immunization program or its designation as a recommended vaccine for travelers is also crucial. This research aims to determine dengue vaccine hesitancy and its associated factors among non-endemic international travelers visiting Thailand, providing valuable insights for future vaccine recommendations and discussions.
Objectives:
- To study the dengue vaccine hesitancy among non-endemic international travelers visiting Thailand.
- To assess the factors associated with the dengue vaccine hesitancy among non-endemic international travelers visiting Thailand.
Methodology:
The cross-sectional study will recruit 390 international travelers who visit the Hospital for Tropical Diseases, Bangkok, and three public sites which are the area near the Grand Palace, Khaosan Road, and the snake farm at Queen Saovabha Memorial Institute. Data collection involves a one-time gathering of information, with eligible participants willing to provide informed consent. The questionnaire can be done both paper-based and online-based (JOTFORM), which takes time around 10-15 minutes. The questionnaire consists of 3 main parts including, a question assessing dengue vaccine hesitancy, knowledge about dengue vaccination, and demographic data. The questionnaire for estimating dengue vaccine hesitancy was derived from previous literature and validated with the pilot cohort of 20 participants. The study prioritizes ethical considerations, confidentiality, and data management to ensure participant welfare and data security.
Study design
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Non-endemic international travelers | Experimental | Other: Questionnaire |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Male and female international travelers from dengue-non-endemic countries
- Age ≥18 years old
- Able to read and understand English questionnaire
- Willing to participate in the study Endemic countries of dengue will be defined as all countries in the ASEAN(Association of Southeast Asian Nations) economic community countries, Central and South American countries except Chile, and ten countries in Eastern Mediterranean and Africa showing high frequency of dengue transmission according to WHO(World Health Organization) and ECDC(European Centre for Disease Prevention and Control) data(Yemen, Egypt, Sudan, Eritrea, Djibouti, Tanzania, Kenya, Ethiopia, Somalia, Burkina Faso). Non-endemic countries refer to all the other countries apart from endemic countries.
Key exclusion criteria (2 listed)
- Travelers who are visiting the hospital for dengue vaccination or dengue infection or dengue-like symptoms, which is defined as acute fever with one of the following; rash, myalgia, headache, nausea, vomiting, retro-orbital pain.
- Participants who are expatriate workers or lived in Thailand or other Southeast Asia countries for more than 1 year.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| QuestionnaireAdapted design questionnaire to estimate the vaccine hesitancy specifically for dengue vaccine | Other | Non-endemic international travelers |
Primary outcome
Dengue vaccine hesitancy score
Time frame: Baseline
Spectrum of the dengue vaccine hesitancy score will be assessed by the 15 items questionaire with 7 likert scales adapting from 5C determinants of the vaccine hesitancy. The score ranging from 3-45 for each 5 domains. Higher score will represent stronger impact for each determinants; the positive determinants are confidence and collective responsibility while negative determinants are constraints, complacency, and calculation.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Oct 2026.
- Results publication: PubMed 42289086Charoenwisedsil R, Lawpoolsri S, Rattanaumpawan P, Ruenroengbun N, Flaherty GT, Parker DM, Ngamprasertchai T. Barriers to dengue vaccine uptake in international travelers: a mixed-methods study. Expert Rev Vaccines. 2026 Dec;25(1):2689612. doi: 10.1080/14760584.2026.2689612. Epub 2026 Jun 21.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Questionnaire in people with Vaccine Hesitancy, run by Mahidol University at 1 site in Thailand.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Thailand. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Dengue vaccine hesitancy score (time frame: Baseline). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06418854, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Oct 2026.