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CompletedNCT06418854Updated Feb 20, 2025

Dengue Vaccine Hesitancy Among International Travelers

An interventional study of Questionnaire in Vaccine Hesitancy, sponsored by Mahidol University. Completed at 1 site in Thailand. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-02-20.

Sponsored by Mahidol University · Not applicable, Interventional, and Prevention

Phase
Not applicable
Study type
Interventional
Enrollment
390
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study 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. 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

  1. Questionnaire to estimate vaccine hesitancy on each 5 domains.
  2. Knowledge about dengue infection and vaccination
  3. 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:

  1. To study the dengue vaccine hesitancy among non-endemic international travelers visiting Thailand.
  2. 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.

02

Conditions studied

  • Vaccine Hesitancy

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Keywords

  • Dengue vaccine hesitancy
  • International travelers
  • 5C(Confidence, Complacency, Constraints, Risk calculation, Collective responsibility) model
03

In context

Dengue

279 studies on the registry are indexed under Dengue; 45 are open to participants now.

This study's enrollment of 390 is above the median of 123 across 195 interventional studies indexed under Dengue.

Browse Dengue studies →

Lead sponsor

Mahidol University is the lead sponsor of 730 studies on the registry; 118 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • 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.

Exclusion criteria

Exclusion Criteria

  • 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.
05

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
390 participants (actual)

Study arms

  • Experimental
    Non-endemic international travelers

    Other: Questionnaire

Interventions

  • OtherQuestionnaire

    Adapted design questionnaire to estimate the vaccine hesitancy specifically for dengue vaccine

06

What researchers measure

Primary outcomes

  1. 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.

    Time frame: Baseline

07

Study locations

1 site
  • Hospital for Tropical Diseases
    Bangkok, Ratchathewi 10400, Thailand
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Feb 20, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT06418854
Lead sponsor
Mahidol University
Responsible party
Thundon Ngamprasertchai, MD (Assoc.Prof., Mahidol University) — Principal investigator
First posted
May 17, 2024
Start date
Jun 1, 2024
Primary completion
Nov 1, 2024
Completion
Dec 31, 2024
Last update
Feb 20, 2025

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Jan 2025. You cannot join it, but the record below documents what was studied.

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