Testing The Effectiveness Of Two Interventions To Reduce Vaccine Hesitancy Among Adolescents

Not Applicable

Completed

• Conditions: Vaccine Hesitancy; Vaccine Refusal; Health Knowledge, Attitudes, Practice

• Registration Number: NCT06155877
• Lead Sponsor: Centre National de la Recherche Scientifique, France

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2022-11-15
• Primary Completion: 2023-06-23
• Study Completion: 2023-06-23
• Status Verified: 2023-11
• Study First Submitted: 2023-11-09
• Study First Submitted QC: 2023-11-24
• Last Update Submitted: 2023-11-24
• Study First Posted: 2023-12-05
• Last Update Posted: 2023-12-05

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 8590

Inclusion Criteria

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

Exclusion Criteria

• Do not understand French

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Attitude towards vaccination	Up to 8 months	Participants' attitude towards vaccination were measured as the average agreement with 4 questions measured on a 7-points Likert Scale created for this study, ranging from 1 - "Completely disagree" to 7 - "Totally agree", where a higher score corresponds to more positive attitudes towards vaccination.; "The vaccines used in France are effective" "The vaccines used in France are safe" "Vaccines are useful because they protect us from dangerous diseases". "It is important to get vaccinated to protect others". For the full questionnaire, see the experiment's OSF repository.; All outcomes were assessed three times: before teachers received our interventions (November 15th - December 12th), in the middle of the school year (March 6th -June 8th), and after all teachers used our interventions (May 11th - June 23rd).

Secondary Outcome Measures

Name	Time	Method
Knowledge about vaccination	Up to 8 months	Knowledge is measured as the average number of correct answers to 11 True or False questions: "Vaccines are not necessary, since diseases can be treated by drugs (such as antibiotics)" "Without vaccines, smallpox would still exist" "The effectiveness of vaccines has been scientifically proven" "Children would be more resistant if they did not receive so many vaccines" "Vaccination can cause certain disorders, such as autism, multiple sclerosis or diabetes" "If a child receives too many vaccines at once, it can overload their immune system" "The chemicals included in vaccines are not dangerous" "Vaccination increases the risk of developing allergies" "Vaccines are injected too early, which prevents children from building their immune systems" "Vaccines cannot cause the disease they protect against" "Thanks to scientific advances, scientists can create vaccines with fewer side effects"; Like all other outcomes, knowledge was assessed three times during the year.
Intention to be vaccinated	Up to 8 months	Intention to be vaccinated is measured as the average agreement with 5 questions, measured on a 7-points Likert Scale created for this study, ranging from 1 - "Completely disagree" to 7 - "Totally agree", where a higher score corresponds to a stronger intention to be vaccinated.; "If a vaccine for a new disease becomes available, I would get vaccinated" "If an AIDS vaccine became available, I would get vaccinated" "If a common cold vaccine became available, I would get vaccinated" "If a gastroenteritis vaccine became available, I would get vaccinated" "If a vaccine for certain cancers became available, I would get vaccinated" For the full questionnaire, see the experiment's OSF repository; All outcomes were assessed three times: before teachers received our interventions (November 15th - December 12th), in the middle of the school year (March 6th -June 8th), and after all teachers used our interventions (May 11th - June 23rd).

Trial Locations

Locations (1)

Institut Jean Nicod, Département d'études cognitives, École Normale Supérieure, Université PSL, EHESS, CNRS; 🇫🇷 Paris, France