CompletedPhase 3

Safety Study of a Vaccine to Help Protect Against Lyme Disease in Healthy Children

United States3,547 participantsStarted 2022-12-12

Plain-language summary

This study is to understand if the study vaccine (called VLA15) is safe in healthy children. We are looking for children who: * are healthy * are age 5 through 17 * have not been diagnosed with any form of Lyme disease in the past * have not received any vaccines for Lyme disease in the past Lyme disease happens most often in children of this age. The study vaccine may be used potentially to help prevent Lyme disease. The goal of this study is to get more information about the safety of the study vaccine in this age group. Participants will be in this study for about 2 years. During that time, they will receive VLA15 or placebo (sterile saltwater solution) by a "shot" in the arm. We will compare experience of children receiving VLA15 to those receiving the placebo. Participants will not know whether they get VLA15 or placebo. Everyone participating in this study will: * get the shots in a clinic or in a hospital office * receive a total of 4 shots * receive the first 3 shots within 6 months * receive the last shot about 1 year afterwards * need to come to the trial site for 6 planned visits; 4 of these are vaccination visits and 2 are follow-up visits. We will contact you by phone 1 time every year during the study to monitor your experience. You may have extra visits if you experience a severe reaction after a vaccine dose.

Who can participate

Age range5 Years – 17 Years

SexALL

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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Healthy participants at enrollment who are determined to be eligible for inclusion in the study. Participants with preexisting chronic medical conditions determined to be stable may be included. * Participants and/or participants' parent(s)/guardian who are willing and able to comply with all scheduled visits, study procedures and lifestyle considerations for the duration of the study. Exclusion Criteria: * Female participants that are pregnant, breastfeeding, or have a positive urine pregnancy test at Visit 1. Sexually active females and fertile males unwilling to use contraception as per protocol. * Any contraindication to vaccination or vaccine components, including previous anaphylactic reaction to any vaccine or vaccine-related components. * Any diagnosis of Lyme disease within the past 3 months. * Any history of Lyme arthritis, carditis, neuroborreliosis, or other disseminated Lyme Disease (LD), regardless of when diagnosed. * Known tick bite within the past 4 weeks. * Congenital or acquired immunodeficiency or other conditions or treatments associated with immunosuppression that would inhibit the ability to mount an immune response to a vaccine. * Other medical, psychiatric condition, active suicidal ideation/behavior or lab abnormality which increases risk of study participation or, in investigator's judgment is inappropriate for the study. * Receipt of a previous vaccination for LD. * Treatment for LD in the 3 months prior to study interventi…

What they're measuring

Percentage of Participants With at Least 1 Local Reaction of Any Grade for up to 7 Days Following Study Vaccination 1

Timeframe: From Day 1 through Day 7 after Study Vaccination 1 (Vaccination on Day 1, Month 0)

Percentage of Participants With at Least 1 Local Reaction of Any Grade for up to 7 Days Following Study Vaccination 2

Timeframe: From Day 1 through Day 7 after Study Vaccination 2 (Vaccination on Day 1, Month 2)

Percentage of Participants With at Least 1 Local Reaction of Any Grade for up to 7 Days Following Study Vaccination 3

Timeframe: From Day 1 through Day 7 after Study Vaccination 3 (Vaccination on Day 1, Month 6)

Percentage of Participants With at Least 1 Local Reaction of Any Grade for up to 7 Days Following Study Vaccination 4 (Booster Dose)

Timeframe: From Day 1 through Day 7 after Study Vaccination 4 (Vaccination on Day 1, Month 18)

Percentage of Participants With at Least 1 Local Reaction of Any Grade for up to 7 Days After Any Study Vaccination

Timeframe: From Day 1 through Day 7 after any study vaccination

Percentage of Participants With at Least 1 Systemic Event of Any Grade for up to 7 Days Following Study Vaccination 1

Timeframe: From Day 1 through Day 7 after Study Vaccination 1 (Vaccination on Day 1, Month 0)

Trial details

NCT IDNCT05634811

SponsorPfizer

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-07-21

Results submitted2026-04-14

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