Evaluation of an Interactive Risk Information Tool to Increase COVID-19 Vaccination Incidence in Vaccine-hesitant People (iWILL)

Evaluation of an Interactive Risk Information Tool to Increase COVID-19 Vaccination Incidence in Vaccine-hesitant People During Omicron Wave in Germany

Coronavirus (COVID-19) vaccines have saved millions of lives since release and remain a key tool in the fight against the pandemic.

However, most countries have not reached the vaccine uptake rates needed to relieve pressure on hospitals and intensive care units (ICUs) during peak corona periods. Reduced effectiveness of vaccines in preventing infections with the Omicron variant and milder courses of the disease may trigger and support beliefs that vaccination is no longer necessary, especially among vaccine sceptics.The term 'vaccine sceptic', however, is used heterogeneously and often interchangeably to describe both 'vaccine hesitants' and 'vaccine deniers'. In contrast to vaccine deniers, characterized by a definite and unwavering decision not to get vaccinated, vaccine hesitants are characterized by a spectrum of indecisiveness, with a high need for information on both benefits and harms. They may still decide to get vaccinated if information succeeds in convincing them. In light of the potential for a change of mind in vaccine-hesitants the key question is: How does one best address their high needs for balanced risk ratio information? Evidence from cognitive and behavioral science suggests that interactive simulations of risk information, which imitate mechanisms by which humans sequentially and experientially sample risk information naturally, can be more effective in helping people develop adequate risk perceptions and initiate behavioral change than the ubiquitously used conventional text-based formats. The study therefore seeks to determine if interactive risk ratio simulation relative to a text-based format are more effective in prompting positive change in unvaccinated, vaccine-hesitant respondents' intention to get the COVID-19 and also in the respective benefit-to-harm ratio assessment during the Omicron wave in Germany.

Study Overview

• Status: Recruiting
• Conditions: COVID-19 Infection
• Intervention / Treatment: Behavioral: Simulation; Behavioral: Text

Detailed Description

The iWILL study is a cross sectional study that aims to evaluate the effectiveness of interactive risk ratio simulation (intervention) relative to a text-based format (control) in COVID-19 vaccine-hesitant people in Germany.

The objectives of iWILL are:

1. to adapt the already piloted, digital, interactive, evidence-based counseling tool ExploreVac (focus on herd protection) as well as a new simulation (focus on individual protection) to the most current evidence (including age adjustment) for communicating vaccine effectiveness and side effects as evidence-based patient information using the example of COVID-19 vaccination,
2. to implement the adapted version of ExploreVac and the new simulation in care with the aim to increase the vaccination incidence among vaccine hesitant individuals, to improve their subjective assessment of vaccination's benefits and harms, and to reduce the presumed increased counseling effort of the GP compared to standard care,
3. to test whether the intervention is superior as compared to the control on these endpoints,
4. to draw conclusions about the transferability of the developed method for other established vaccinations (HPV, influenza protection) and vaccinations for future infectious diseases.

Primary hypothesis:

(H1) The intervention group (interactive simulations) will show a higher positive change (T0/baseline to T1/after intervention) in vaccination intention than the control group (text-based information).

Secondary hypotheses:

(H2) The intervention group (interactive simulations) will show a higher positive change (T0/baseline to T1/after intervention) in their positive subjective benefit-to-harm assessment of the COVID-19 vaccine's benefit-to-harm ratio than does the control group.

(H3) The intervention group reports a lower need for additional counseling by their GPs than does the control group.

(H4) The intervention group (interactive simulations) will show a higher correspondence between their intended behavior (T1) and their actual reported vacccinataion behavior (T2/ follow-up after 6 months).

Recruitment of unvaccinated, vaccine hesitant German residents will be established by using probability-based internet panels maintained by respondi (Cologne, Germany). The study will be pursued with cross-sectional national sample.

Intervention condition: two interactive simulations informing 1) about absolute risks of infection, hospitalization, ICU admission, and death after exposure to COVID-19 relative to vaccination's side effects (e.g., myocarditis in men ≤35 years) in 100,000 vaccinated and 100,000 unvaccinated individuals, all adjustable to four different age groups (18- 34 years, 35-59 years, 60-79 years, ≥ 80 years due to considerable differences in each of the depicted risks (Supplement) and 2) about the benefits of vaccination for the population as a whole (herd) in terms of preventing infections and deaths.

Control condition (see also below): two text module informing 1) about absolute risks of infection, hospitalization, ICU admission, and death after exposure to COVID-19 relative to vaccination's side effects (e.g., myocarditis in men ≤35 years) in 100,000 vaccinated and 100,000 unvaccinated individuals, all adjustable to four different age groups (18- 34 years, 35-59 years, 60-79 years, ≥ 80 years due to considerable differences in each of the depicted risks (Supplement) and 2) about the benefits of vaccination for the population as a whole (herd) in terms of preventing infections and deaths.

The educative information material in both conditions is based on non-directive evidence-based patient counseling according to the guideline on evidence-based health information. After the study condition, participants are informed that any further questions about vaccination can be discussed with the GP.

The questionnaire at T0 (baseline) and T1 (directly after the intervention) takes maximum 10 minutes to complete (without exploration of intervention material). Given that participants are free to spend as much time as participants want with the educative information material, the total survey time can be longer, however.

About six months after first participation in the study, participants are re-contacted via e-mail and are asked to fill out a second questionnaire (6-months follow-up, T2), which approximately takes about 5 minutes to complete to learn more about potential the translation of the intention into vaccination behavior.

• Study Type: Interventional
• Enrollment (Anticipated): 1188
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Odette Wegwarth, Prof. Dr.; Phone Number: +49(0) 30 450 531 074; Email: odette.wegwarth@charite.de
• Study Contact Backup: Name: Clara O Schirren, MA; Phone Number: +49(0) 30 450 - 531 056; Email: clara.schirren@charite.de

Study Locations

• Germany
  • Berlin, Germany
    • Recruiting
    • Charité - Universitätsmedizin Berlin
    • Contact: Odette Wegwarth, Prof. Dr.; Phone Number: +49(0) 30 450 - 531 074; Email: odette.wegwarth@charite.de
    • Principal Investigator: Odette Wegwarth, Prof. Dr.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Hesitancy towards COVID-19 vaccination
• Not yet vaccinated against COVID-19
• Age ≥ 18 years.

Exclusion Criteria:

• No hesitancy towards COVID-19 vaccination
• Already vaccinated
• Age < 18 years.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intervention: Simulation; Interactive information tools	Behavioral: Simulation; The participants in the intervention group receive two interactive simulations in addition to a general text module that provides sequential, animated information on the spread of the virus without prevention, the effectiveness of vaccination and potential side effects of vaccination on a herd protection level and the individual level.
Other: Control: Text; Standard text-based information	Behavioral: Text; The participants in the control group receive two text-based information in addition to a general text module that provides information on the spread of the virus without prevention, the effectiveness of vaccination and potential side effects of vaccination on a herd protection level and the individual level. Both conditions ensure the provision of a level of knowledge that at least corresponds to standard care.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline vaccination intention at T1	Change in 5-point response scale of vaccination intention between baseline and post-intervention judgement "I will definitely get the COVID-19 vaccination"; "I will probably get the COVID-19 vaccination"; "I am unsure if I will get the COVID-19 vaccination"; "I will probably not get the COVID-19 vaccination", and "I will definitely not get the COVID-19 vaccination." NOTE: This scale is categorical, that means values are only used to distinguish between the 5 categories and DO NOT indicate better or worse outcomes.	Immediately after Intervention (T1)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline assessment of vaccine-related benefiit-to-harm at T1	Change in 5-point response scale of vaccine-related benefiit-to-harm assessment The benefits of the COVID-19 vaccination clearly outweigh the harms," "The benefits of the COVID-19 vaccination somewhat outweigh the harms," "Benefits and harms of the COVID-19 vaccination are balanced," "The harms of the COVID-19 vaccination somewhat outweigh the benefits," "The harms of the COVID-19 vaccination clearly outweigh the benefits." NOTE: This scale is categorical, that means values are only used to distinguish between the 5 categories and DO NOT indicate better or worse outcomes.	Immediately after Intervention (T1)
Number of GP counselings at 6-months follow-up	Measured by the number of visits of the GP to receive additional counselling on the vaccine after study intervention/control	6-months follow up (T2)
Actual vaccination behavior at T2	Used to check for correspondence between vaccination intention expressed at T1 and actual behvavior at T2	6-months follow up (T2)

Collaborators and Investigators

• Sponsor: Charite University, Berlin, Germany
• Collaborators: Ludwig-Maximilians - University of Munich; Universitätsklinikum Hamburg-Eppendorf; Max Planck Institute for Human Development; Federal Joint Committee; University Medical Center Mainz
• Investigators: Principal Investigator: Odette Wegwarth, Prof. Dr., Charite University, Berlin, Germany

Study record dates

Study Major Dates

• Study Start (Actual): February 3, 2022
• Primary Completion (Anticipated): January 31, 2023
• Study Completion (Anticipated): February 28, 2023

Study Registration Dates

• First Submitted: December 14, 2021
• First Submitted That Met QC Criteria: January 3, 2022
• First Posted (Actual): January 18, 2022

Study Record Updates

• Last Update Posted (Actual): December 28, 2022
• Last Update Submitted That Met QC Criteria: December 23, 2022
• Last Verified: December 1, 2022

More Information

Terms related to this study

• Keywords: COVID-19 vaccination, vaccine-hesitancy
• Additional Relevant MeSH Terms: Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Virus Diseases; Infections; Respiratory Tract Infections; Respiratory Tract Diseases; Pneumonia, Viral; Pneumonia; Lung Diseases; COVID-19
• Other Study ID Numbers: VSF1_2021-194

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No