Vaccine-Preventable Diseases, Vaccine Refusal
Conditions
Keywords
Vaccine hesitancy, Google ads, Vaccine messages, Vaccine confidence
Brief summary
The success of vaccination programs often depends on the effectiveness of the vaccine messages, particularly during emergencies such as the COVID-19 pandemic. The current suboptimal uptake of COVID-19 vaccines across many parts of the world highlights the tremendous challenges in overcoming vaccine hesitancy and refusal even in the context of a world-devastating pandemic. The investigators conducted a randomized controlled trial in Hong Kong to evaluate the impact of seven vaccine messages on COVID-19 vaccine uptake (with the government slogan as the control). The participants included 127,000 individuals who googled COVID-19-related information during July-October 2021.
Detailed description
This study aims to evaluate the effectiveness of using the Google advertising platforms on influencing the uptake of COVID-19 vaccines in Hong Kong. When completed, the rich database compiled through this proposed study will provide increased insight into vaccine hesitancy in Hong Kong. Insights from the optimised online advertising trial can aid in providing crucial technical and theoretical support to the relevant health authorities for any potential evidence-based policy intervention in addressing vaccine hesitancy issues or the public's concerns towards vaccines in Hong Kong.
Interventions
BEHAVIORALGoogle ads
Individuals who googled COVID-19 information in Hong Kong were randomized to see one of the seven ads and, if they clicked on the ads, the corresponding vaccine message on our website
Sponsors
The University of Hong Kong
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Healthy volunteers
Yes
Inclusion criteria
* General users of Google search in Hong Kong
Exclusion criteria
* None
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of bookings following each message delivery within 6 hours | 6 hours | The number of bookings made within X = 6 hours following each message delivery |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of bookings following each message delivery within 3 hours | 3 hours | The number of bookings made within X = 3 hours following each message delivery |
| Number of bookings following each message delivery within 12 hours | 12 hours | The number of bookings made within X = 12 hours following each message delivery |
Countries
Hong Kong
Outcome results
None listed