Clinical trial NCT06155877: Testing The Effectiveness Of Two Interventions To Reduce Vaccine Hesitancy Among Adolescents
Official title: Interventions to Reduce Vaccine Hesitancy Among Adolescents: A Randomized Controlled Trial.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Vaccine Hesitancy
Vaccine Refusal
Health Knowledge, Attitudes, Practice
Lead sponsor: Centre National de la Recherche Scientifique, France
Sponsor class: OTHER
Collaborators: name: Université Paris-Dauphine
name: Fondation La main à la pâte
name: Direction de l Évaluation, de la Prospective et de la Performance
First posted: 2023-12-05
Enrollment: 8590
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Participants were randomized at the school level, to minimize contamination between experimental conditions. Using administrative data, schools were stratified by their Priority Education status and by geographical categories (urban with high density, urban with medium density, rural). Then, within each stratum, schools were matched by triplets using the closest-neighbors approach, minimizing the quadratic distance between schools' success rate at the national end-of-middle school exam and Covid vaccination rate at the EPCI3 level. This resulted in 149 triplets. Within each triplet, schools were randomly assigned to one of the three experimental groups.

Randomization code is available at the experiment's OSF repository:

https://osf.io/rf5w9/?view_only=de759e4e36914c909adeac5fd541babf
Primary purpose: PREVENTION

Brief summary: Vaccines currently prevent several million deaths every year and more lives could be saved if vaccination take up increased. The World Health Organization identifies vaccine hesitancy as one of the ten most important threats to global health and emphasizes the importance of devising interventions to reduce vaccine hesitancy. The two most promising interventions rely on consensus messaging, which has robust but small effects, and interactive discussion, which has larger effects, but is difficult to scale up. School-based interventions aimed at adolescents have the potential to make the best of both types of interventions. Interventions that take place in schools can be conducted over longer periods of time (up to several hours) and are rolled out by a figure that is typically trusted and respected (the teacher). Moreover, intervening during adolescence is particularly timely since important vaccines are delivered at that age (most notably the human papillomavirus vaccine), and because attitudes towards vaccination during adolescence might have a long-lasting impact, as is the case for other health related attitudes.

This study tests the effectiveness of two interventions, a pedagogical intervention based on consensus messaging, and a chatbot intervention designed to mimic interactive discussion, on 9th grade French pupils.


Eligibility criteria: Inclusion Criteria:

* French 9th grade students (equivalent to "troisième")'
* One class per school

Exclusion Criteria:

* Do not understand French

Primary outcomes:
measure: Attitude towards vaccination
timeFrame: Up to 8 months
Secondary outcomes:
measure: Knowledge about vaccination
timeFrame: Up to 8 months
measure: Intention to be vaccinated
timeFrame: Up to 8 months
Other outcomes:
Locations:
city: Paris
country: France
facility: Institut Jean Nicod, Département d'études cognitives, École Normale Supérieure, Université PSL, EHESS, CNRS
Study officials:
affiliation: Institut Jean Nicod, Département d'études cognitives, École normale supérieure, Université PSL, EHESS, CNRS
name: Hugo Mercier, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Institut Jean Nicod, Département d'études cognitives, École normale supérieure, Université PSL, EHESS, CNRS
name: Coralie Chevallier, PhD
role: PRINCIPAL_INVESTIGATOR
References: