NCT05477524|Active Not RecruitingPhase 3DMCFDA Drug

An Efficacy, Safety, Tolerability, Immunogenicity, and Lot-Consistency Clinical Trial of a 6-Valent OspA-Based Lyme Disease Vaccine (VLA15)

VALOR

A Phase 3, Multicenter, Placebo-Controlled, Randomized, Observer-Blinded Trial to Evaluate the Efficacy, Safety, Tolerability, Immunogenicity, and Lot Consistency of a 6-Valent OspA-Based Lyme Disease Vaccine in Healthy Participants ≥5 Years of Age

Pfizer ClinicalTrials.gov

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2 other identifiers

C46010032023-509105-72-00

Study Type

interventional

Target

12,547

Locations

7 countries

Sites

120

Timeline

RegisteredJul 2022

StartedAug 2022

CompletionDec 2025

Brief Summary

The main purpose of this clinical study is to evaluate a 6-valent OspA-based Lyme disease vaccine (VLA15) for prevention of Lyme disease within North America and Europe. Approximately 9,400 healthy participants (this number excludes participants from 8 sites which were terminated for quality issues) 5 years and older will be recruited from areas with high levels of endemic Lyme disease to receive VLA15 or placebo (an inactive substance consisting of saltwater). Each participant will have about a 50% chance of receiving VLA15 and about a 50% chance of receiving placebo. A subset of participants will receive VLA15 from 3 different lots or placebo (1:1:1:3 ratio) to assess lot equivalence. Participants will receive a 3-dose primary vaccination series at about 0, 2, and 5 to 9 months and then receive a booster dose about 12 months after end of primary vaccination series. Vaccination of participants will occur at a time of year such that the primary series is completed before the peak Lyme disease season followed by a booster dose just prior to the beginning of the second Lyme disease season. A subset of participants will be followed for a third Lyme disease season. Comparison will be made between the Lyme disease cases of people receiving the study vaccine to those of the people who are not. This will help us determine if the study vaccine is safe and effective. If enrolled, participants will need to visit the research site at least 7 times during the study, and for a subset of participants up to 9 times. There will also be at least 5 telephone contacts. It is expected that each participant will take part in this study for up to about 2 and a half years. The subset of participants followed for a third Lyme disease season will take part in this study for up to about to 3 and a half years.

Trial Health

Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date

Enrollment

12,547

participants targeted

Target at P75+ for phase_3

Timeline

Completed

Started Aug 2022

Typical duration for phase_3

Geographic Reach

7 countries

120 active sites

Status

active not recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

3.4 years study duration

First Submitted

Initial submission to the registry

July 5, 2022

Completed

23 days until next milestone

First Posted

Study publicly available on registry

July 28, 2022

Completed

7 days until next milestone

Study Start

First participant enrolled

August 4, 2022

Completed

3.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 26, 2025

Completed

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 26, 2025

Completed

Last Updated

September 29, 2025

Status Verified

September 1, 2025

Enrollment Period

3.4 years

First QC Date

July 5, 2022

Last Update Submit

September 25, 2025

Conditions

Lyme Disease

Keywords

VLA15Lyme BorreliosisVaccineTick

Outcome Measures

Primary Outcomes (10)

Relative incidence rate reduction of confirmed Lyme disease cases in the VLA15 group compared to the placebo group
A confirmed case of Lyme disease, caused by B burgdorferi sensu lato, is defined as a clinically suspected case of Lyme disease that is confirmed by PCR, culture, microbial cell-free B burgdorferi-specific DNA sequencing, or serological antiborrelial antibody assay, and finally assessed and confirmed to be a case by the independent Adjudication Committee
Beginning 1 month after receiving the booster dose (28 days after receiving the booster dose through the end of the Lyme disease season following the booster dose (end of October)).
Percentage of participants reporting local reactions
Within 7 days following each study intervention administration
Percentage of participants reporting systemic events
Within 7 days following each study intervention administration
Percentage of participants reporting adverse events (AEs)
Through 1 month following each study intervention administration
Percentage of participants reporting newly diagnosed chronic medical conditions (NDCMCs)
Through study completion, up to approximately 42 months.
Percentage of participants reporting serious adverse events (SAEs)
Through study completion, up to approximately 42 months.
Geometric mean ratio (GMR) of anti-OspA titers for each serotype (ST1-ST6) for Lot 1 to Lot 2
At 1 month after completion of the primary series and the booster dose
Geometric mean ratio (GMR) of anti-OspA titers for each serotype (ST1-ST6) for Lot 1 to Lot 3
At 1 month after completion of the primary series and the booster dose
Geometric mean ratio (GMR) of anti-OspA titers for each serotype (ST1-ST6) for Lot 2 to Lot 3
At 1 month after completion of the primary series and the booster dose
Geometric mean ratio (GMR) of anti-OspA titers for each serotype (ST1-ST6)
Immunobridging objective to determine non-inferiority between 5-17 year old and 18-44 year old participant strata.
At 1 month after completion of the booster dose

Secondary Outcomes (2)

Vaccine efficacy among participants enrolled from North American sites
Through the end of the Lyme disease season beginning 1 month after receiving the booster dose (28 days after completion of the booster dose until end of October)
Vaccine efficacy among participants after primary series
Through the end of the Lyme disease season beginning 1 month after completing the primary series (28 days after completion of the primary series until end of October)