Clinical trial NCT05182554: COVID-19 Messaging for Vaccination
Official title: Increasing the Effectiveness and Diffusion of COVID-19 Messaging for Vaccination
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Vaccination Refusal
COVID-19 Pandemic
Keywords: Covid-19 Vaccine
Social Media
Lead sponsor: Massachusetts Institute of Technology
Sponsor class: OTHER
Collaborators: name: Facebook, Inc.
name: Code3
name: Stanford University
name: Harvard University
name: Yale University
name: Johns Hopkins University
name: Massachusetts General Hospital
name: Ludwig-Maximilians - University of Munich
name: National Institutes of Health (NIH)
First posted: 2022-01-10
Enrollment: 6
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: There are four arms in the study which geographic areas are assigned to in parallel. The geographic areas in the three treatment arms will receive a Facebook ad campaign over the same time period to one another.
Primary purpose: TREATMENT

Brief summary: This study will distribute videos of health professionals encouraging Covid-19 vaccination to a large sample of Facebook users, and will test the most effective ways to maximize diffusion of this vaccine-related content to increase vaccination rates. The study sample will be U.S. states where vaccination rates remained low in fall 2021. The experimental design is an RCT with 4 groups, randomized at the county level: 1) a control group which receives no intervention, 2) a treatment group in which Facebook users receive ads which include videos of health professionals telling them to get vaccinated, 3) a treatment group in which Facebook users receive ads which include videos of health professionals encouraging them to help their friends to get vaccinated, and 4) a treatment group in which Facebook users receive ads which include videos of health professionals encouraging them to get their most influential friends to help their friends get vaccinated. In treatments 3 and 4, participants will have the option to sign up to be a "vaccine ambassador," in which case they will get notifications when the study team posts new vaccine-related content, and will receive reminders about encouraging their friends to be vaccinated. The vaccine ambassadors will also be entered into a lottery to win prizes. The study team is building a website to host the videos of health professionals which answer common questions about Covid-19 vaccination. The investigators will measure engagement with the vaccine-related content as well as assess effects on vaccination rates at the county level.

Detailed description: The study will have three treatment arms and a control group. Each of the treatments will be randomized at the county level and will be initiated through a Facebook ad campaign.

Experimental Sample: The experimental sample includes all states where less than 60% of the total population had received a first dose of Covid-19 vaccine by October 21, 2021. There are 1402 counties in the 19 states satisfying those criteria (Alabama, Alaska, Arkansas, Georgia, Idaho, Iowa, Indiana, Louisiana, Michigan, Mississippi, Missouri, Montana, North Dakota, Ohio, Oklahoma, South Carolina, Tennessee, West Virginia, Wyoming). Excluding the five counties with missing data, there are 1,397 counties in the experiment, of which there are 468 counties in the control group, 310 counties in T1 ("direct" messaging) treatment, 309 counties in T2 ("friends" messaging), and 310 counties in T3 ("gossips" messaging).

The following procedures will be used:

* Treatment Group 1 ("Direct" messaging): The investigators will conduct a Facebook ad campaign to show content about COVID-19 vaccination to a large number of Facebook users. Facebook will allocate ad credits across users in treatment areas. The ads will be displayed twice per week for 3-4 weeks. Like for any Facebook ad, individuals can choose to whether or not to watch the video and can close the ad at any time. If individuals wish, they can also share any of the content with others. The videos shown in the ads will be hosted on our project Facebook page "Doctors for Coronavirus Prevention." As in previous projects by the investigators, a health professional (normally wearing a white coat or scrubs) will read very short scripts directly onto the camera (see eg. https://www.facebook.com/doctors4covidprevention/posts/104965558099200 for an example).
* Treatment Group 2 ("Friends" messaging): For this group, the Facebook ad campaign will recruit individuals to become "vaccine ambassadors" to help spread the word about vaccination to their friends, families and communities. Recruitment ads will be disseminated in a similar manner to the content in T1. Individuals will be able to share the ad with others. Individuals interested in learning more can click through a link in the ad to the vaccine ambassador webpage. Participants can consume or share any of the information on the webpage. Interested individuals can also enroll formally as vaccine ambassadors. They can share their contact information with the study to a) be entered into prize lotteries, b) receive reminders to share content with others, c) be contacted in the future for possible follow-up surveys. They will be asked to give their informed consent at this time and will be screened based on whether they live in a treated county and whether they are 18 years or older.
* Treatment Group 3 ("Gossips" messaging): This treatment looks the same as Treatment Group 2, except the recruitment ads will differ slightly. If the individual clicks through to learn more about vaccine ambassadors, they will also be reminded to share the invitation with people they know who are often the source of important news or information.
* Control: individuals in these counties will receive no intervention and will never be contacted by members of the study team.

Treatment and control status at the county level will be merged with aggregated and de-identified datasets to measure COVID vaccinations, COVID symptoms, and cases, and engagement with the vaccine ambassador content.

The study team will create a series of websites with materials that the vaccine ambassadors can share with friends, family and others in their communities. This same content will be disseminated through sponsored Facebook ads in T1. On the website, the framing of the vaccine-related videos with either a "fact" or "myth" frame will be randomized. The purpose is to study which framing is more effective at engaging users.

Eligibility criteria: Inclusion Criteria:

* Facebook user
* Over 18 years old
* In a geographic area targeted by the study

Exclusion Criteria:

-

Primary outcomes:
measure: Changes in County-Level Covid-19 Vaccination Measured by Inverse Hyperbolic Sine
timeFrame: During intervention (6 weeks) and after intervention (3 weeks)
Secondary outcomes:
Other outcomes:
Locations:
city: Cambridge
country: United States
facility: Massachusetts Institute of Technology
state: Massachusetts
Study officials:
affiliation: Massachusetts Institute of Technology
name: Esther Duflo, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Massachusetts Institute of Technology
name: Ben Olken, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Massachusetts Institute of Technology
name: Abhijit Banerjee, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Harvard Kennedy School
name: Marcella Alsan, MD, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Stanford University
name: Arun Chandrasekhar, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Harvard University
name: Emily Breza, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Yale University
name: Paul Goldsmith-Pinkham, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Johns Hopkins School of Nursing
name: Emily Hoppe, PhD Student
role: PRINCIPAL_INVESTIGATOR
affiliation: Massachusetts Institute of Technology
name: Pierre-Luc Vautrey, PhD Student
role: PRINCIPAL_INVESTIGATOR
affiliation: Massachusetts Institute of Technology
name: Lisa Ho, PhD Student
role: PRINCIPAL_INVESTIGATOR
affiliation: MGH/McLean Harvard Psychiatry Program
name: Lucy Ogbu-Nwobodo, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: Harvard Medical School & Massachusetts General Hospital
name: Erica Warner, ScD, MPH
role: PRINCIPAL_INVESTIGATOR
affiliation: Massachusetts General Hospital
name: Carlos Torres, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: Harvard Medical School & Massachusetts General Hospital
name: Fatima Stanford, MD, MPH, MPA
role: PRINCIPAL_INVESTIGATOR
affiliation: Ludwig-Maximilians - University of Munich
name: Sarah Eichmeyer, PhD
role: PRINCIPAL_INVESTIGATOR
References: