Communication Intervention to Improve Influenza Vaccination Rates Among Elderly in Can Tho

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.

Inclusion Criteria: * 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. Exclusion Criteria: * 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.