COVID-19 vaccine messaging on social media in Kenya

ISRCTN ISRCTN49683523
DOI https://doi.org/10.1186/ISRCTN49683523
Secondary identifying numbers 1034BUSA21
Submission date
16/05/2022
Registration date
17/05/2022
Last edited
24/01/2023
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Other
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
Although there are many information campaigns on social media to promote COVID vaccines, it is unclear what types of messaging and messengers are the most effective in increasing COVID vaccine confidence and uptake. The primary objective of the study is to evaluate the source credibility of international and local messengers and how varying messengers improve vaccine outcomes.

Who can participate?
This study recruits participants over the age of 18 years.

What does the study involve?
This is an online experiment with an in-survey experiment that tests the impact of (1) international COVID vaccine messaging content and (2) localized COVID vaccine messaging content on source credibility and vaccine outcomes in Kenya.

What are the possible benefits and risks of participating?
The possible benefits include a better understanding for how international campaigns can be effective in delivering public health messages. There are no foreseeable risks for participating in the research study.

Where is the study run from?
Busara Center for Behavioral Economics (Kenya)

When is the study starting and how long is it expected to run for?
October 2021 to June 2023

Who is funding the study?
Vaccine Confidence Fund (USA)

Who is the main contact?
Dr Kelly Zhang, kwzhang@mit.edu

Contact information

Dr Kelly Zhang
Principal Investigator

5th Floor
Daykio Plaza
Ngong Ln
Nairobi
-
Kenya

ORCiD logoORCID ID 0000-0002-1406-0480
Phone +254 715476334
Email kwzhang@mit.edu

Study information

Study designSingle-center interventional randomized controlled trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Internet/virtual
Study typePrevention
Participant information sheet Not available in web format, please use contact details to request a participant information sheet.
Scientific titleTrusted messengers in improving vaccine outcomes in Kenya
Study objectivesCurrent study hypothesis as of 23/01/2023:
H1: Messaging from international health organizations increases the source credibility of a message.
H2: Messaging from local healthcare workers increases the source credibility of a message.
H3: Local healthcare workers are more effective than international health organizations in increasing the source credibility of a message for those who distrust international health organizations.
H4: Messaging from international health organizations improves vaccine outcomes.
H5: Messaging from local healthcare workers improves vaccine outcomes.
H6: Local crowdsourced content improves vaccine outcomes.
H7: Local healthcare workers are more effective than international health organizations in improving vaccine outcomes for those who distrust international health organizations.
H8: Local crowdsourced content is more effective than international health organizations in improving vaccine outcomes for those who distrust international health organizations.

Previous study hypothesis:
H1: Country crowdsourced content increases vaccine confidence and uptake.
H2: Country healthcare worker version of general international content increases vaccine confidence and uptake.
H3: Country crowdsourced original content is more effective than general international content in increasing vaccine confidence and uptake.
H4: Country healthcare worker version of general international content is more effective than general international content in increasing vaccine confidence and uptake.
H5: Country crowdsourced version of general international content is more effective than general international content in increasing vaccine confidence and uptake.
Ethics approval(s)1. Approved 16/11/2021, Massachusetts Institute of Technology under Committee on the Use of Humans as Experimental Subjects (E25-143b, 77 Mass Ave, Cambridge, MA 02139, USA; +1 617-253-6787; couhes@mit.edu), ref: #2201000541 and #2110000475
2. Approved 16/11/2021, Health Media Lab IRB (Health Media Lab, Inc., 1101 Connecticut Avenue, NW Suite 450, Washington, DC 20036 USA; +1 202.246.8504; info@hmlirb.com), ref: #1034BUSA21
Health condition(s) or problem(s) studiedSource credibility and vaccine outcomes
InterventionCurrent interventions as of 23/01/2023:
The in-survey experiment has four treatment arms, one control group, and one placebo group. Each treatment arm consists of one video with content length around 20-30 seconds. Randomization is done using Qualtrics.

The treatment arms are as follows:
Treatment 1: International healthcare organization (WHO) message
Treatment 2: Local healthcare worker version of WHO message (T1)
Treatment 3: Local crowdsourced version of WHO message (T1)
Treatment 4: Local crowdsourced message (original content)
The control group only receives the message text with no messenger, while the placebo group receives nature videos from one message source (National Geographic). If there are no significant differences between the placebo and control groups, they will pooled into one group for analysis.

Previous interventions:
The in-survey experiment has 5 treatment arms and 1 control group. Each treatment arm consists of 1 video with content length around 30-40 seconds. The control group does not receive any videos. The randomization will be done using R, Qualtrics, or Facebook's randomization tool for A/B testing.

The treatment groups are as follows: T0 is a placebo international nature video that has no public health content, T1 is the status quo of general international content, T2 is country crowdsourced original content, T3 is country healthcare worker version of general international content, and T4 is country crowdsourced version of general international content.

The most effective treatment for each country is then tested in a competitive information environment through a news feed experiment, where we boost the visibility of one of the treatment arms relative to no content being shown. The boosted treatment arm will be the treatment with the largest average treatment effect from that country’s in-survey experiment, or T1 content if there are null effects.
Intervention typeBehavioural
Primary outcome measureCurrent primary outcome measures as of 23/01/2023:
Measured post-treatment within the survey:
1. Source Credibility:
1.1. Trustworthiness, scaled from 0-5. Please rate the trustworthiness of this content is on a scale of 1-5, where 1 is the worst content and 5 is the best content in your opinion [5 star option]
1.2. Expertise, scaled from 0-5. Please rate the expertise of this content is on a scale of 1-5, where 1 is the worst content and 5 is the best content in your opinion [5 star option]
2. COVID Vaccine Outcomes:
2.1. COVID vaccine knowledge, binary indicator for correct answer: correct answer of ”Herd immunity protects those who can’t be vaccinated, because the disease is less likely to reach them.”
2.2. COVID vaccination acceptance, binary indicator for yes. If a COVID-19 vaccine was available to you, would you take it?
2.3. COVID vaccine uptake, binary indicator for participation. Participating in a COVID vaccine pledge campaign where 1 = Yes, 0 = No.
3. General Vaccine Outcomes:
3.1. Influenza vaccination acceptance, binary indicator for yes: If the influenza vaccine was available to you, would you take it?
3.2. Cholera vaccination acceptance, binary indicator for yes: If the cholera vaccine was available to you, would you take it?
3.3. Pneumonia vaccination acceptance, binary indicator for yes: If the pneumonia vaccine was available to you, would you take it?
3.4. Seeks vaccine information, binary indicator for yes: Would you like to sign up to receive more information about how to access the influenza, cholera, or pneumonia vaccines? Please enter your email address if you would like to receive more information, otherwise please leave it blank.

Previous primary outcome measures:
Measured at baseline and the endline (2 weeks):
1. COVID vaccine confidence is measured as the mean across the following items: (1) COVID vaccine acceptance, where 1 = Yes, 0 = No, 0.5 = Maybe; (2) If a COVID-19 vaccine was available to you, would you take it?; (3) I will take a vaccine to protect myself from having COVID-19 in the future, where 1 = Strongly agree/Agree, 0 = Disagree/Strongly disagree/Not sure or don’t know.
2. COVID vaccine uptake is measured as the mean of the following two binary indicators: (1) Participating in a COVID vaccine pledge campaign where 1 = Yes, 0 = No; (2) Providing proof of COVID vaccination where 1 = Provides proof, 0 = No proof.
Secondary outcome measuresCurrent secondary outcome measures as of 23/01/2023:
Measured post-treatment within the survey:
1. Backlash:
1.1. Haha reaction, with a binary indicator: Selects haha reaction emoji
1.2. Angry reaction, with a binary indicator: Selects haha reaction emoji
2. Local Healthcare Outcomes:
2.1. Binary indicator for trust in the local healthcare workers: Personally, how much trust do you have in Kenyan healthcare workers? (1 = Trust them a great deal/Tend to trust them, 0 =Tend to distrust them/Distrust them greatly/Not sure or don’t know)
2.2. Support for local healthcare workers: amount donated out of 100 Ksh to local healthcare workers
3. Misinformation:
3.1. Believes in COVID conspiracy theory, binary indicator for yes: Do you believe in any conspiracy theories around COVID? If yes, please describe here.
3.2. Believes that vaccines protect against serious diseases, binary indicator for yes: Do you believe that vaccines can protect you from serious diseases?

Previous secondary outcome measures:
Measured at baseline and the endline (2 weeks):
1. Prosocial vaccination index is the mean of: (1) I will take a vaccine to protect my family/members of my household against having COVID-19 in the future, where 1 = Strongly agree/Agree 0 = Disagree/Strongly disagree; (2) I will take a vaccine to protect my community against having COVID-19 in the future, where 1 = Strongly agree/Agree 0 = Disagree/Strongly disagree.
2. Vaccine norms index is the mean of: To what extent do you agree with the following statement: Most people in [Kenya/Nepal/the Philippines] should go to get vaccinated against COVID-19, where 1 = Strongly agree/Agree 0 = Disagree/Strongly disagree; (2) If you had a family member or friend who was unsure whether to accept the COVID-19 vaccine, how likely would you be to encourage them to get the vaccine, where 0 = Extremely unlikely to 100 = Extremely likely, re-scaled to be from 0 to 1 for the index.
Overall study start date01/10/2021
Completion date01/06/2023

Eligibility

Participant type(s)Healthy volunteer
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants15000
Key inclusion criteriaOver the age of 18 years
Key exclusion criteriaIf an individual has already participated in a related survey for the study.
Date of first enrolment20/05/2022
Date of final enrolment01/03/2023

Locations

Countries of recruitment

  • Kenya

Study participating centre

Not applicable, online surveys
N/A
N/A
N/A
Kenya

Sponsor information

Busara Center for Behavioral Economics
Research organisation

5th Floor
Daykio Plaza
Ngong Ln
Nairobi
-
Kenya

Phone +254 715476334
Email chaning.jang@busaracenter.org
Website https://busaracenter.org/
ROR logo "ROR" https://ror.org/032f13a22

Funders

Funder type

Charity

Vaccine Confidence Fund

No information available

Results and Publications

Intention to publish date01/12/2024
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryStored in publicly available repository
Publication and dissemination planPlanned publication in a high-impact peer-reviewed journal
IPD sharing planThe anonymized raw data will be shared on Open Science Framework.

Editorial Notes

24/01/2023: Nepal and the Philippines were removed from the countries of recruitment.
23/01/2023: The following changes have been made:
1. The public title was changed from 'COVID-19 vaccine messaging on social media in Kenya, Nepal, and the Philippines' to 'COVID-19 vaccine messaging on social media in Kenya'.
2. The scientific title was changed from 'Evaluation of social media content on COVID-19 vaccine messaging in Kenya, Nepal, and the Philippines' to 'Evaluation of social media content on COVID-19 vaccine messaging in Kenya'.
3. The study hypothesis, interventions, primary and secondary outcome measures were updated.
4. The study design was changed from 'Multi-center interventional randomized controlled trial' to 'Single-center interventional randomized controlled trial'.
5. The condition was changed from 'COVID vaccine confidence and vaccine uptake' to 'Source credibility and vaccine outcomes'.
6. The target number of participants was changed from 87000 to 15000.
7. The plain English summary was updated to reflect these changes.
8. The recruitment end date was changed from 01/08/2023 to 01/03/2023.
9. The overall trial end date was changed from 01/09/2023 to 01/06/2023.
09/08/2022: The following changes have been made:
1. The recruitment end date has been changed from 01/08/2022 to 01/08/2023.
2. The overall trial end date has been changed from 01/09/2022 to 01/09/2023 and the plain English summary updated accordingly.
3. The intention to publish date has been changed from 01/12/2023 to 01/12/2024.
16/06/2022: The following changes have been made:
1. The recruitment end date has been changed from 14/06/2022 to 01/08/2022.
2. The overall trial end date has been changed from 15/06/2022 to 01/09/2022 and the plain English summary has been updated to reflect this change.
3. The intention to publish date has been changed from 01/12/2022 to 01/12/2023.
17/05/2022: Trial's existence confirmed by HML IRB.