InfluenzaCIVECTNCT07508189
Communication Intervention to Improve Influenza Vaccination Rates Among Elderly in Can Tho
A study testing Multi-component Health Communication Package in people with Influenza and Vaccination Coverage, run by Can Tho University of Medicine and Pharmacy at 1 site in Vietnam.
Trial summary
This study evaluates the effectiveness of a multi-component community-based communication intervention to increase influenza vaccination rates among adults aged above 65 years in Can Tho City, Vietnam. Read more about this study
- Who is it for?
- Ages 66 years and olderHealthy volunteers can take part
- Conditions the study is for
- Influenza, Vaccination Coverage, Health Communication
- What is being tested?
- Multi-component Health Communication Package
- Type of treatment
- Vaccines, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1,237 participants
- Where
- 1 siteVietnam
- Study dates
- 1 Sep 2025to 9 Sep 2026
- Phase
- Interventional
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 66 years and older
- All sexes
- Healthy volunteers accepted
- Older adult
Who may be able to join
- Residents living in selected wards/communes in Can Tho City for at least 6 months.
- Aged above 65 years.
- Mentally and physically capable of participating in interviews and receiving communication interventions.
- Agree to participate in the study and provide informed consent.
Who cannot join
- Individuals with severe cognitive impairment or dementia.
- Individuals with contraindications to influenza vaccination.
- Planning to move out of the study area during the 12-month follow-up period.
Trial locations and contacts
1 site in 1 country.
Vietnam1 site
Can Tho University of Medicine and Pharmacy
Can Tho, Can Tho City, 900000
About this study
Official title: Effectiveness of Community-Based Communication Interventions to Improve Influenza Vaccination Rates Among the Elderly in Vietnam: A Cluster Randomized Controlled Trial
This study evaluates the effectiveness of a multi-component community-based communication intervention to increase influenza vaccination rates among adults aged above 65 years in Can Tho City, Vietnam. Using a cluster randomised controlled trial design with stratified lottery randomisation, four study sites were selected from eight sites surveyed in a prior study: O Mon Ward and Truong Thanh Commune (intervention); Phuoc Thoi Ward and Truong Xuan Commune (control). The intervention includes community health education sessions, healthcare worker training, household visits, health communication banners, and Zalo-based vaccination reminders, delivered over 12 months (September 2025 to September 2026). Effectiveness is assessed by comparing pre- and post-intervention outcomes using Difference-in-Differences (DID) analysis.
Read the detailed description
This study employs a cluster randomised controlled trial (cluster RCT) design with a repeated cross-sectional approach. The unit of randomisation is the cluster (ward or commune).
RANDOMISATION:
From eight study sites surveyed in Objective 1 (four urban wards and four rural communes in Can Tho City), four sites were selected by stratified lottery randomisation. Within each stratum (urban and rural), one site was randomly assigned to the intervention group and one to the control group by lottery draw without investigator discretion:
- Intervention: O Mon Ward (urban) and Truong Thanh Commune (rural)
- Control: Phuoc Thoi Ward (urban) and Truong Xuan Commune (rural)
PARTICIPANTS:
All eligible permanent residents aged above 65 years at each study site were invited to participate. Data are collected at two independent cross-sectional time points:
- T0: Baseline survey, August 2025 (n=952)
- T1: Follow-up survey, September 2026 (n=approximately 1,200) Participants at T0 and T1 are not necessarily the same individuals; the design captures population-level changes within randomised clusters.
INTERVENTION (12 months: September 2025 to September 2026):
The 12-month duration encompasses both active implementation and the time required for knowledge, attitude, and behaviour change.
Phase 1 (September 2025, intensive activities):
- Two community health education sessions per intervention site for adults aged >65 years and one cohabiting family member, with distribution of printed educational leaflets on influenza disease and vaccination. Attendance: O Mon Ward: Session 1 = 60 older adults + 40 family members, Session 2 = 57 older adults + 35 family members; Truong Thanh Commune: Session 1 = 60 + 38, Session 2 = 50 + 30.
- One capacity-building workshop per site for healthcare workers and community health volunteers in vaccination counselling (O Mon Ward: n=30; Truong Thanh Commune: n=20).
- Thirty household visits per site by trained community health volunteers to reinforce vaccination counselling.
Phase 2 (September 2025 to September 2026, ongoing):
- Health communication banners displayed at health stations and community information centres throughout the intervention period.
- Healthcare worker vaccination counselling integrated into all routine clinical contacts at intervention site health stations.
- Zalo-based digital communication: weekly educational content and personalised vaccination reminders (December 2025 to January 2026, coinciding with peak influenza season in southern Vietnam).
CONTROL GROUP:
Received routine primary healthcare only, with no additional study-related activities.
ANALYSIS:
Effectiveness is measured using Difference-in-Differences (DID) regression, comparing changes between T0 and T1 across intervention and control clusters. Models use multivariable logistic regression (binary outcomes) and linear regression (continuous outcomes), adjusted for sociodemographic covariates. Intraclass correlation coefficients (ICC) were estimated for all outcomes and found to be negligible (ICC < 0.01), confirming the appropriateness of individual-level DID analysis.
- Conditions
- Influenza, Vaccination Coverage, Health Communication
- Being tested
- Multi-component Health Communication Package
- Keywords
- Influenza Vaccines, Elderly, Health Communication, Vaccination Coverage, Community-based Intervention, Vietnam
- Medical subject headings
- Influenza, Human
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Multi-component Health Communication PackageBehavioural
A 12-month cluster-level communication intervention (Sep 2025-Sep 2026) delivered in two phases to all adults aged >65 years in intervention clusters:
Phase 1 (Sep 2025): (1) Two community health education sessions/site with influenza leaflets for older adults and family members; (2) HCW capacity-building workshop/site (O Mon: n=30; Truong Thanh: n=20); (3) Thirty household visits/site by community health volunteers.
Phase 2 (ongoing): (4) Health communication banners at health stations and community centres; (5) HCW point-of-care vaccination counselling at all clinical contacts; (6) Zalo-based weekly educational content and vaccination reminders (Dec 2025-Jan 2026).
| Study group | Role | What they receive |
|---|---|---|
| Multi-component Health Communication | Experimental | Adults aged >65 years in 2 intervention clusters (O Mon Ward and Truong Thanh Commune) receive a multi-component package:
Phase 1 (Sep 2025): (1) Two community health education sessions/ site for older adults and one family member, with influenza leaflets. (2) One HCW capacity-building workshop/site (O Mon: n=30; Truong Thanh: n=20). (3) Thirty household visits/site by community health volunteers.
Phase 2 (Sep 2025-Sep 2026): (4) Health communication banners at health stations and community centres. (5) HCW point-of-care vaccination counselling at all clinical contacts. (6) Zalo-based weekly reminders and educational content (Dec 2025-Jan 2026). Receives: Behavioral: Multi-component Health Communication Package |
| Routine Immunization Information | No intervention | Participants in this arm receive standard care and routine immunization information provided by the local health station without the additional communication package. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Influenza vaccination uptake in the preceding 12 months
Proportion of participants who received influenza vaccination in the 12 months prior to survey, assessed by self-report. Baseline assessed August 2025; follow-up assessed September 2026. Intervention effect estimated using Difference-in- Differences (DID) regression comparing change between intervention and control clusters.
Measured: Up to 12 months
Secondary outcomes (6)
Influenza vaccination in calendar year 2025
Proportion vaccinated against influenza during calendar year 2025, assessed by self-report at follow-up (September 2026).
Measured: Up to 12 months
Influenza vaccination intention
Proportion intending to receive influenza vaccination in the next 12 months, assessed by self-report at baseline (August 2025) and follow-up (September 2026).
Measured: Baseline and up to 12 months
Healthcare worker vaccination counselling
Proportion who received influenza vaccination counselling from a healthcare worker or community health volunteer in the preceding 12 months, assessed by self-report at baseline (August 2025) and follow-up (September 2026).
Measured: Baseline and up to 12 months
Influenza knowledge score
Total knowledge score (0-6) on influenza disease aetiology, transmission, complications, and vaccine characteristics. Higher scores indicate greater knowledge. Assessed at baseline (August 2025) and follow-up (September 2026). Analysed using linear regression DID.
Measured: Baseline and up to 12 months
Vaccine hesitancy score (WHO-SAGE Vaccine Hesitancy Scale)
Vaccine hesitancy measured using the WHO-SAGE Vaccine Hesitancy Scale (Vietnamese-adapted version). Higher scores indicate greater hesitancy. Assessed at baseline (August 2025) and follow-up (September 2026). Analysed using linear regression DID.
Measured: Baseline and up to 12 months
Willingness to pay for influenza vaccination
Proportion willing to pay out-of-pocket costs for influenza vaccination, assessed by self-report binary question at baseline (August 2025) and follow-up (September 2026).
Measured: Baseline and up to 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Apr 2026
- Study start1 Sep 2025
- Primary completion9 Sep 2026
- Study completion9 Sep 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for InfluenzaStudies of the same condition, open and under way.
- 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
- Randomised
- Intervention model
- Parallel groups
- Model description
- A cluster randomized controlled trial where wards/communes are the unit of randomization. Participants in intervention clusters receive multi-component communication, while control clusters receive standard care.
- Masking
- None (open label)
- Enrolment
- 1,237 participants (actual)
Sponsor and investigators
- Lead sponsor
- Can Tho University of Medicine and Pharmacy
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Hygiene and Epidemiology, Vietnam
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07508189
- Sponsor's protocol ID
- NIHE IRB - 40/2025
- Acronym
- CIVECT
- Status last verified
- Sep 2026
- First submitted
- 27 Mar 2026
- Last updated
- 28 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be shared with other researchers to ensure the privacy and confidentiality of the study participants, in accordance with local ethical guidelines and institutional policies. Only aggregated results will be made available through publications.