Vaccination Knowledge and AcceptanceY4F WP5/3NCT07921121
Assessment of Communication Interventions on Vaccination Knowledge and Acceptance
A study testing Intervention group 1 and Intervention group 2 in people with Vaccination Knowledge and Acceptance and Informed Vaccine-decision Making, run by Charite University, Berlin, Germany at 1 site in Germany.
Trial summary
An online randomized controlled trial (RCT) examining the effectiveness of communication measures regarding TBE vaccination in the European context and yellow fever vaccination in the South American context on an informed vaccination decision. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Vaccination Knowledge and Acceptance, Informed Vaccine-decision Making
- What is being tested?
- Intervention group 1 and Intervention group 2
- Type of treatment
- Vaccines, Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 1,524 participants
- Where
- 1 siteGermany
- Study dates
- 23 Oct 2026to Nov 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- German citizens
- Colombian citizens
Who cannot join
- Citizens of all other countries
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Germany1 site, 1 recruiting
- Recruiting
Charité - Universitätsmedizin Berlin, Berlin-Mitte
Berlin, State of Berlin, 10117
About this study
Official title: Effectiveness Assessment of Communication Interventions to Improve Vaccination Knowledge and Acceptance
An online randomized controlled trial (RCT) examining the effectiveness of communication measures regarding TBE vaccination in the European context and yellow fever vaccination in the South American context on an informed vaccination decision. Building on an exploratory qualitative focus group study conducted in 2024 with vaccine-hesitant individuals (Ethics Committee Approval Number EA1/119/24) and an exploratory quantitative study conducted in 2025 among the general population in Germany and Colombia (Ethics Committee Approval Number EA2/112/25), the communication measures were designed to improve education about vaccinations and to increase individual willingness to be vaccinated.
Read the detailed description
The study design consists of an online survey. The questionnaire and the communication measures were developed in collaboration with the following partners: the Amsterdam Institute for Global Health and Development (AIGHD) in Amsterdam, the Netherlands, and CIDEIM (Centro Internacional de Entrenamiento e Investigaciones Médicas) in Cali, Colombia, based on the findings of the previous focus group studies and the subsequent quantitative study on the prevalence of knowledge about and acceptance of novel (flavivirus) vaccines and perceived barriers to vaccination among the general population in Germany and Colombia.
Potential participants will be invited to participate in the study by the panel provider Toluna via a link in an email. Individuals who express their willingness to participate will first be asked questions about their sociodemographic background, their vaccination status against TBE (Germany) or yellow fever (Colombia), as well as their perception of risk regarding TBE or yellow fever and the associated vaccinations.
Participants will then be randomly assigned in a 1:1:1 ratio to one of three study arms:
- Control group (in Germany, a vaccination check based on the COVID-19 vaccination check on infektionsschutz.de; in Colombia, an educational video about the yellow fever vaccination from the Colombian Ministry of Health)
- Intervention group 1: Information format A (website)
- Intervention group 2: Information format B (slideshow/carousel)
In both countries, the intervention formats are implemented in the same way; only the vaccination being addressed differs (TBE in Germany, yellow fever in Colombia).
Within the two intervention groups, A and B, there is also a second randomized assignment to a presentation of an established (inactivated vaccine or live vaccine) versus a novel vaccine technology ("NovaCarrier"). This second randomization ensures that the assignment to vaccine technologies within the respective formats is not systematically linked to other participant characteristics. It serves exclusively to explore possible effects of the vaccine technologies on attitudes and intentions and does not form the basis of the primary case number planning.
Participants who view the materials featuring the hypothetical novel vaccine technology are transparently informed at the end of the study that this is a hypothetical technology.
Following the intervention, all participants will complete an adapted Informed Choice questionnaire (Marteau et al., 2001), which assesses risk understanding, knowledge, attitudes, and intention to be vaccinated against TBE or yellow fever. Subsequently, risk perception is assessed again after viewing an informational piece, and finally, participantsare asked two open-ended questions about safety and information needs regarding vaccinations.
The drafted communication measures will first be tested in a pilot study (n = 150; 75 participants per country) in order to adjust the materials to be developed before the main study (n = 1,374; 687 participants per country) if necessary. For this pilot study, the same questionnaire as for the main study will be used, with the addition of three open-ended questions regarding the information formats. The pilot study is not intended for final hypothesis testing, but solely to optimize the informational materials to be tested and, if necessary, the survey questions.
- Being tested
- Intervention group 1, Intervention group 2, Control format (vaccine check)
- Keywords
- vaccination knowledge, vaccination acceptance, TBE vaccine knowledge, TBE vaccine acceptance, yellow fever vaccine knowledge, yellow fever vaccine acceptance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intervention group 1Behavioural
Participants are shown informational material A (website)
Intervention group 2Behavioural
Participants are shown informational material B (slideshow/carousel)
Control format (vaccine check)Other
Participants are shown the control informational material (vaccine check)
| Study group | Role | What they receive |
|---|---|---|
| Intervention group 1 (website) | Active comparator | Participants are shown informational material A (website) before completing an adapted informed choice questionnaire that assesses participant risk understanding, knowledge, attitudes, and intention to get vaccinated against TBE/yellow fever. Receives: Behavioral: Intervention group 1 |
| Intervention group 2 (slideshow/carousel) | Active comparator | Participants are shown informational material B (slideshow/carousel) before completing an adapted informed choice questionnaire that assesses participant risk understanding, knowledge, attitudes, and intention to get vaccinated against TBE/yellow fever. Receives: Behavioral: Intervention group 2 |
| Control group (vaccine check) | Placebo comparator | Participants are shown the control informational material (vaccine check) before completing an adapted informed choice questionnaire that assesses participant risk understanding, knowledge, attitudes, and intention to get vaccinated against TBE/yellow fever. Receives: Other: Control format (vaccine check) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Relative frequency of informed decisions based on respective informational material
The relative frequency of informed decisions based on the respective materials developed. Participants are classified into "informed" and "uninformed" based on their responses and the instrument developed my Marteau et al. (2001)
Measured: Immediately post intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Nov 2026
- Study start23 Oct 2026
- Primary completionNov 2026 (estimated)
- Study completionNov 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Vaccination Knowledge and AcceptanceStudies of the same condition, open and under way.
- More trials run by Charite University, Berlin, GermanyThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 1,524 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Charite University, Berlin, Germany
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Odette Wegwarth, Charite University, Berlin, Germany
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07921121
- Sponsor's protocol ID
- 2026_Y4F_WP5.3
- Acronym
- Y4F WP5/3
- Status last verified
- Nov 2026
- First submitted
- 2 Nov 2026
- Last updated
- 6 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effectiveness Assessment of Communication Interventions to Improve Vaccination Knowledge and Acceptance
- ClinicalTrials.gov ID
- NCT07921121
- Acronym / sponsor ID
- Y4F WP5/3 / 2026_Y4F_WP5.3
- Keywords
- vaccination knowledge, vaccination acceptance, TBE vaccine knowledge, TBE vaccine acceptance, yellow fever vaccine knowledge, yellow fever vaccine acceptance
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 1,524 participants (estimated)
- Lead sponsor
- Charite University, Berlin, GermanyUniversity, hospital or other
- Study start
- 23 Oct 2026 (actual)
- Primary completion
- Nov 2026 (estimated)
- Study completion
- Nov 2026 (estimated)
- First posted
- 6 Nov 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
An online randomized controlled trial (RCT) examining the effectiveness of communication measures regarding TBE vaccination in the European context and yellow fever vaccination in the South American context on an informed vaccination decision. Building on an exploratory qualitative focus group study conducted in 2024 with vaccine-hesitant individuals (Ethics Committee Approval Number EA1/119/24) and an exploratory quantitative study conducted in 2025 among the general population in Germany and Colombia (Ethics Committee Approval Number EA2/112/25), the communication measures were designed to improve education about vaccinations and to increase individual willingness to be vaccinated.
Detailed description
The study design consists of an online survey. The questionnaire and the communication measures were developed in collaboration with the following partners: the Amsterdam Institute for Global Health and Development (AIGHD) in Amsterdam, the Netherlands, and CIDEIM (Centro Internacional de Entrenamiento e Investigaciones Médicas) in Cali, Colombia, based on the findings of the previous focus group studies and the subsequent quantitative study on the prevalence of knowledge about and acceptance of novel (flavivirus) vaccines and perceived barriers to vaccination among the general population in Germany and Colombia.
Potential participants will be invited to participate in the study by the panel provider Toluna via a link in an email. Individuals who express their willingness to participate will first be asked questions about their sociodemographic background, their vaccination status against TBE (Germany) or yellow fever (Colombia), as well as their perception of risk regarding TBE or yellow fever and the associated vaccinations.
Participants will then be randomly assigned in a 1:1:1 ratio to one of three study arms:
- Control group (in Germany, a vaccination check based on the COVID-19 vaccination check on infektionsschutz.de; in Colombia, an educational video about the yellow fever vaccination from the Colombian Ministry of Health)
- Intervention group 1: Information format A (website)
- Intervention group 2: Information format B (slideshow/carousel)
In both countries, the intervention formats are implemented in the same way; only the vaccination being addressed differs (TBE in Germany, yellow fever in Colombia).
Within the two intervention groups, A and B, there is also a second randomized assignment to a presentation of an established (inactivated vaccine or live vaccine) versus a novel vaccine technology ("NovaCarrier"). This second randomization ensures that the assignment to vaccine technologies within the respective formats is not systematically linked to other participant characteristics. It serves exclusively to explore possible effects of the vaccine technologies on attitudes and intentions and does not form the basis of the primary case number planning.
Participants who view the materials featuring the hypothetical novel vaccine technology are transparently informed at the end of the study that this is a hypothetical technology.
Following the intervention, all participants will complete an adapted Informed Choice questionnaire (Marteau et al., 2001), which assesses risk understanding, knowledge, attitudes, and intention to be vaccinated against TBE or yellow fever. Subsequently, risk perception is assessed again after viewing an informational piece, and finally, participantsare asked two open-ended questions about safety and information needs regarding vaccinations.
The drafted communication measures will first be tested in a pilot study (n = 150; 75 participants per country) in order to adjust the materials to be developed before the main study (n = 1,374; 687 participants per country) if necessary. For this pilot study, the same questionnaire as for the main study will be used, with the addition of three open-ended questions regarding the information formats. The pilot study is not intended for final hypothesis testing, but solely to optimize the informational materials to be tested and, if necessary, the survey questions.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Intervention group 1 (website) | Active comparator | Behavioral: Intervention group 1Participants are shown informational material A (website) before completing an adapted informed choice questionnaire that assesses participant risk understanding, knowledge, attitudes, and intention to get vaccinated against TBE/yellow fever. |
| Intervention group 2 (slideshow/carousel) | Active comparator | Behavioral: Intervention group 2Participants are shown informational material B (slideshow/carousel) before completing an adapted informed choice questionnaire that assesses participant risk understanding, knowledge, attitudes, and intention to get vaccinated against TBE/yellow fever. |
| Control group (vaccine check) | Placebo comparator | Other: Control format (vaccine check)Participants are shown the control informational material (vaccine check) before completing an adapted informed choice questionnaire that assesses participant risk understanding, knowledge, attitudes, and intention to get vaccinated against TBE/yellow fever. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- German citizens
- Colombian citizens
Key exclusion criteria (1 listed)
- Citizens of all other countries
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Intervention group 1Participants are shown informational material A (website) | Behavioural | Intervention group 1 (website) |
| Intervention group 2Participants are shown informational material B (slideshow/carousel) | Behavioural | Intervention group 2 (slideshow/carousel) |
| Control format (vaccine check)Participants are shown the control informational material (vaccine check) | Other | Control group (vaccine check) |
Primary outcome
Relative frequency of informed decisions based on respective informational material
Time frame: Immediately post intervention
The relative frequency of informed decisions based on the respective materials developed. Participants are classified into "informed" and "uninformed" based on their responses and the instrument developed my Marteau et al. (2001)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Nov 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Intervention group 1 and Intervention group 2 in people with Vaccination Knowledge and Acceptance and Informed Vaccine-decision Making, run by Charite University, Berlin, Germany at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 6 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Odette Wegwarth, Prof. Dr. (+49 30 450 531 074, odette.wegwarth@charite.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Relative frequency of informed decisions based on respective informational material (time frame: Immediately post intervention). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2026.