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OpenTrials
Completed

NCT Number: NCT05499299

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

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.

Completed

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Key information

Conditions

Vaccine-Preventable Diseases Behavior Health Behavior Infections Treatment Adherence and Compliance Treatment Refusal Vaccination Hesitancy Vaccination Refusal Vaccine Refusal

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

The University of Hong Kong

Hong Kong

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • General users of Google search in Hong Kong

Exclusion criteria

  • None

Treatment and study plan

Google ads

Behavioral

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

Primary outcomes

  1. Number of bookings following each message delivery within 6 hours

    Time frame: 6 hours

    The number of bookings made within X = 6 hours following each message delivery

Secondary outcomes

  1. Number of bookings following each message delivery within 3 hours

    Time frame: 3 hours

    The number of bookings made within X = 3 hours following each message delivery

  2. Number of bookings following each message delivery within 12 hours

    Time frame: 12 hours

    The number of bookings made within X = 12 hours following each message delivery

Sponsors and collaborators

Lead sponsor

The University of Hong Kong

Other

Registry information

Official study title

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

Important dates

Study start
2021
Primary completion
2021
Study completion
2022
First posted
Aug 12, 2022
Registry last updated
Aug 16, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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