NCT05499299

Volatility and Heterogeneity of Vaccine Sentiments Means Continuous Monitoring is Needed When Measuring Message Effectiveness

The Effect of Optimised Online Advertising on the Uptake of COVID-19 Vaccines in Hong Kong

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 127,000 (actual)
• Sponsor: The University of Hong Kong · Academic / Other
• Sex: All
• Age: —
• Healthy volunteers: Accepted

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.

Conditions

• Vaccine-Preventable Diseases
• Vaccine Refusal

Interventions

Type	Name	Description
BEHAVIORAL	Google 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

Timeline

• Start date: 2021-07-01
• Primary completion: 2021-10-31
• Completion: 2022-04-01
• First posted: 2022-08-12
• Last updated: 2022-08-16

Locations

1 site across 1 country: Hong Kong