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

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

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05477524
Acronym
VALOR
Enrollment
12546
Registered
2022-07-28
Start date
2022-08-04
Completion date
2026-01-07
Last updated
2026-06-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Lyme Disease

Keywords

VLA15, Lyme Borreliosis, Vaccine, Tick

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.

Interventions

BIOLOGICALVLA15

Shot in the deltoid muscle (preferable in the nondominant arm)

OTHERSaline

Shot in the deltoid muscle (preferable in the nondominant arm)

Sponsors

Pfizer
Lead SponsorINDUSTRY
Valneva Austria GmbH
CollaboratorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
5 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

Key Inclusion Criteria: * Participants who reside in areas with endemic Lyme disease and who lead lifestyles that put them at increased risk for Lyme disease. For example, this could include, but not be limited to: * Individuals who work in B burgdorferi-infected/tick-infested areas, especially those with occupations that may be associated with higher risk of exposure, such as landscaping, forestry, and wildlife and parks management. * Individuals who pursue recreational activities such as hiking, camping, fishing, hunting, jogging, or gardening in such areas. * Individuals who live on land plots with tree lines and come into contact with these trees regularly. * Individuals who have dogs that regularly are outdoors and frequently return with attached ticks. * Individuals who participate in activities in areas with tall grass, smaller wooded areas beside forests, open fields, lakesides, and riversides. Key

Exclusion criteria

* Any female participants that are pregnant (or have a positive urine pregnancy test) or are breastfeeding. * Any diagnosis of Lyme disease within the past 3 months. * Any history of Lyme carditis, neuroborreliosis, or arthritis, or other disseminated Lyme disease regardless of when diagnosed. * Known tick bite within the past 4 weeks. * Newly developed or unstable underlying conditions that may interfere with the assessment of Lyme disease, including but not limited to chronic arthralgia/arthritis, second/third-degree AV heart block, chronic pain syndromes, and chronic skin conditions that reduce the ability to detect cutaneous manifestations of Lyme disease. * Any unstable autoimmune condition with a manifestation (eg, arthritic and neurologic) that may interfere with the assessment of Lyme disease. * Chronic systemic doxycycline or minocycline or other tetracycline class drug use for acne or any other chronic suppressive antibiotics used to treat other conditions.

Design outcomes

Primary

MeasureTime frameDescription
Relative incidence rate reduction of confirmed Lyme disease cases in the VLA15 group compared to the placebo groupBeginning 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)).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
Percentage of participants reporting local reactionsWithin 7 days following each study intervention administration
Percentage of participants reporting systemic eventsWithin 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 2At 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 3At 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 3At 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)At 1 month after completion of the booster doseImmunobridging objective to determine non-inferiority between 5-17 year old and 18-44 year old participant strata using GMRs 1 month after completion of booster dose.
Sero-response of anti-OspA IgG concentrations for each serotype (ST1-ST6)At 1 month after completion of the booster doseImmunobridging objective to determine non-inferiority between 5-17 year old and 18-44 year old participant strata using difference in seroresponse rates 1 month after completion of booster dose.

Secondary

MeasureTime frameDescription
Vaccine efficacy among participants enrolled from North American sitesThrough 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)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
Vaccine efficacy among participants after primary seriesThrough 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)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

Countries

Canada, Finland, Germany, Netherlands, Poland, Sweden, United States

Contacts

STUDY_DIRECTORPfizer CT.gov Call Center

Pfizer

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 5, 2026