Chatbot-delivered Theory-based Online Intervention in Increasing Seasonal Influenza Vaccination Uptake Among Children Aged 3-6 Years

NCT07687719 | Not Yet Recruiting

• 1 other identifier: HMRF24230092
• Study Type: interventional
• Target: 426
• Locations: 0 countries
• Sites: N/A

Brief Summary

This randomized controlled trial will compare the efficacy of a Chatbot-delivered stage-of-change-tailored online intervention versus a Chatbot-delivered non-stage-of-change-tailored online intervention for mothers in increasing seasonal influenza vaccination uptake of their children aged 3-6 years. Mothers of children aged 3-6 years will be randomized evenly into either the intervention or the control group. In the intervention group, the Chatbot will assess mothers' stage of change regarding their children's seasonal influenza vaccination uptake and deliver SOC-tailored interventions through WhatsApp every two weeks for four times. In the control group, the Chatbot will provide a standard and non-stage-of-change-tailored intervention every two weeks for four times. All participants will complete three telephone surveys at baseline (T0), after completion of the intervention (T1) and three months after T1 (T2).

Conditions

Behavior Change

Keywords

Seasonal influenza vaccination uptake

Outcome Measures

Primary Outcomes (1)

• Index child's seasonal influenza vaccination uptake reported by his/her mother with validation

  The research team will ask the participants whether their index children have taken up seasonal influenza vaccination at T2 (3 months after completion of the interventions) using a validated question through telephone interview. The research team will validate the outcome by requesting participants uploading an image of SIV receipt, while hiding personal identification, via the WhatsApp account used in this project.

  3 months after completion of the interventions (T2)

Study Arms (2)

Intervention group

EXPERIMENTAL

Participants in the intervention group will receive chatbot-delivered online interventions tailored to their current stage of change regarding their index child's seasonal influenza vaccination.

Behavioral: Stage-of-change-tailored intervention

Control group

ACTIVE COMPARATOR

Participants in the control group will receive chatbot-delivered standard and non-stage-of-change-tailored interventions

Behavioral: Non-stage-of-change-tailored intervention

Interventions

Stage-of-change-tailored intervention BEHAVIORAL

The Chatbot will deliver four intervention sessions tailored to participants' current stage of change regarding their index child's seasonal influenza vaccination uptake at Week 0, 2, 4, and 6. Participants will also have access to real-time Question-and-Answer (QA) function provided by the chatbot to address their questions related to seasonal influenza vaccination during the intervention period (week 0-6), and they are free to spend as much time as they want on such function.

Intervention group

Non-stage-of-change-tailored intervention BEHAVIORAL

The Chatbot will automatically send participants a link to access a standard online video at week 0, 2, 4 and 6. Participants will also have access to real-time Question-and-Answer (QA) function provided by the chatbot to address their questions related to seasonal influenza vaccination during the intervention period (week 0-6), and they are free to spend as much time as they want on such function.

Control group

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Mothers aged ≥18 years with at least one child aged 3-6 years studying in kindergarten in Hong Kong
• Cantonese speaking
• Having smartphone with internet access
• Already having WhatsApp on the smartphone

You may not qualify if:

• Blindness or deafness
• The index child has known medical contraindications for seasonal influenza vaccination

Sponsors & Collaborators

• Chinese University of Hong Kong: lead

Central Study Contacts

Zixin Wang, PhD

CONTACT

+852 22528474; wangzx@cuhk.edu.hk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: HEALTH SERVICES RESEARCH
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: June 30, 2026
• First Posted: July 7, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): October 31, 2027
• Study Completion (Estimated): October 31, 2027
• Last Updated: July 7, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share