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Lyme BorreliosisPhase 3NCT07226882

A Study to Learn About Different Dosing Schedules of a Lyme Disease Vaccine in Healthy Adults

A Phase 3 study testing VLA15 in people with Lyme Borreliosis, run by Pfizer at 6 sites in United States.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

The purpose of this study is to learn about the safety and effects of the Lyme disease vaccine (called VLA15) when given at different time points. This study is seeking participants who: are generally healthy and between 18 and 44 years of age, have never had a vaccine for Lyme disease before, are not currently… Read more about this study

Who is it for?
Ages 18 to 44 yearsHealthy volunteers can take part
Conditions the study is for
Lyme Borreliosis
What is being tested?
VLA15
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
207 participants
Where
6 sitesUnited States
Study dates
19 Nov 2025to 27 Jan 2028
Phase
Phase 3
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 44 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Participants who are healthy as determined by medical history and clinical judgment.
  • Participants willing and able to comply with all scheduled visits, IP receipt, and other procedures throughout the study.
  • Able to provide Informed Consent.

Who cannot join

  • Pregnant or breastfeeding participants.
  • Allergies or contraindications to vaccines or their components.
  • Health issues including: blood clotting deficiencies, immunodeficiencies, bone marrow disorder, or uncontrolled psychiatric conditions.
  • Receipt of therapies to treat malignancies, blood/plasma products and immunoglobulins, systemic corticosteroids and immunosuppressants, or anticoagulant therapy in recent medical history.
  • Any prior Lyme disease vaccination, or recent or concurrent participation in a separate interventional study.
  • Staff or direct family of the study site staff and Sponsor.

Trial locations and contacts

6 sites in 1 country.

6 sites in 1 country

United States6 sites

  • Smith Allergy and Asthma Specialists

    Cortland, New York, 13045

  • Smith Allergy & Asthma Specialists

    Horseheads, New York, 14845

  • Preferred Primary Care Physicians, Preferred Clinical Research (Ofc 18)

    Pittsburgh, Pennsylvania, 15236

  • Northeast Clinical Trials Group

    Scranton, Pennsylvania, 18510

  • Preferred Primary Care Physicians

    Uniontown, Pennsylvania, 15401

  • IMA Clinical Research Warren

    Warren Township, New Jersey, 07059

Other trials in United States

About this study

Official title: A PHASE 3, PLACEBO-CONTROLLED, DOUBLE-BLINDED, RANDOMIZED STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF DIFFERENT VACCINATION SCHEDULES OF 6-VALENT OSPA-BASED LYME DISEASE VACCINE, VLA15, IN HEALTHY ADULT PARTICIPANTS

The purpose of this study is to learn about the safety and effects of the Lyme disease vaccine (called VLA15) when given at different time points.

This study is seeking participants who:

Read more
  • are generally healthy and between 18 and 44 years of age,
  • have never had a vaccine for Lyme disease before,
  • are not currently taking, or haven't recently taken, medicines like chemotherapy, blood products, or blood thinners, and
  • are not pregnant or breastfeeding and do not plan to become pregnant while receiving the study vaccine.

All participants in this study will receive a total of 5 doses through a shot in the upper arm. Four doses will be the study vaccine (VLA15), and 1 dose will be saltwater.

The study will compare the experiences of people receiving the study vaccine at different time points. This will help see if the study vaccine is safe and will help understand its effect on the body.

Participants will take part in this study for about 2 years. During this time, the participants will have 11 planned visits - 8 will be at the study clinic and 3 will be done over the phone. The clinic visits may include having a health check, giving a small amount of blood (about 20 mL or 4 teaspoons), and getting the study vaccine or saltwater as a shot.

Read the detailed description

This is a Phase 3, randomized, parallel-group, placebo-controlled, double-blinded (third-party unblinded) study to evaluate the safety, tolerability, and immunogenicity of different vaccination schedules of the 6-valent OspA-based Lyme disease (LD) vaccine, VLA15, in healthy participants 18 through 44 years of age.

Participants will be randomized in a 1:1:1:1 ratio to 1 of the 4 parallel study groups. Each participant will receive 4 doses of VLA15 and 1 dose of placebo (saline) at different time points. This study will use an external data monitoring committee (EDMC). The EDMC is independent of the Pfizer study team and includes only external members. The EDMC charter describes the role of the EDMC in more detail.

Approximately 200 participants will be enrolled in the study.

Healthy individuals 18 through 44 years of age who are willing to comply with all study procedures and provide signed informed consent will be enrolled. Pregnant or breastfeeding individuals and fertile individuals who are unwilling or unable to use effective contraceptive methods as outlined in this protocol will not be enrolled. Individuals who have contraindication to vaccination, conditions or treatments that can inhibit the ability to mount an immune response to a vaccine, or other conditions that may increase the risk of study participation will be excluded from this study. Individuals who have previously received a licensed or investigational vaccine for LD will also be excluded from this study.

Being tested
VLA15, Placebo
Keywords
Lyme disease, Lyme Borreliosis, Nervous System, Lyme, Lyme Disease Vaccine
Medical subject headings
Lyme Disease, Lyme Neuroborreliosis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • VLA15Biological

    Participants will receive IM injection of 6-valent OspA-based Lyme disease vaccine

  • PlaceboBiological

    Saline

Study groups in NCT07226882
Study groupRoleWhat they receive
Group 1ExperimentalParticipants will receive 4 doses of VLA15 and 1 dose of placebo injection at different visits. Placebo will be given at Visit 3. Injections will be given as intramuscular shots.
Receives: Biological: VLA15; Biological: Placebo
Group 2ExperimentalParticipants will receive 4 doses of VLA15 and 1 dose of placebo injection at different visits. Placebo will be given at Visit 5. Injections will be given as intramuscular shots.
Receives: Biological: VLA15; Biological: Placebo
Group 3ExperimentalParticipants will receive 4 doses of VLA15 and 1 dose of placebo injection at different visits. Placebo will be given at Visit 7. Injections will be given as intramuscular shots.
Receives: Biological: VLA15; Biological: Placebo
Group 4ExperimentalParticipants will receive 4 doses of VLA15 and 1 dose of placebo injection at different visits. Placebo will be given at Visit 9. Injections will be given as intramuscular shots.
Receives: Biological: VLA15; Biological: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Geometric Mean Concentration (GMC) of Anti-Outer Surface Protein A (OspA) Immunoglobulin G (IgG)

    Measured: At 1 month after the fourth VLA15 dose

  2. Geometric Mean Fold Rise (GMFR) of Anti-Outer Surface Protein A (OspA) Immunoglobulin G (IgG) Concentrations

    Measured: Before the first dose to 1 month after the fourth VLA15 dose

  3. Sero-Response Rate Based on Anti-Outer Surface Protein A (OspA) Immunoglobulin G (IgG) Concentrations.

    Measured: Before the first dose to 1 month after the fourth VLA15 dose

  4. Percentage of Participants With Local Reactions For Each Group

    Measured: Within 7 days after each vaccination

  5. Percentage of Participants With Systemic Events For Each Group

    Measured: Within 7 days after each vaccination

  6. Percentage of Participants With Adverse Events (AEs) For Each Group

    Measured: Within 1 month after each vaccination

  7. Percentage of Participants With Serious Adverse Events (SAEs) For Each Group

    Measured: From the time the participant provides informed consent up to approximately 6 months after the last vaccination

  8. Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) For Each Group

    Measured: From the time the participant provides informed consent up to approximately 6 months after the last vaccination

Secondary outcomes (3)

  1. Geometric Mean Concentration (GMC) of Anti-Outer Surface Protein A (OspA) Immunoglobulin G (IgG)

    Measured: At 1 month after the third VLA15 dose

  2. Geometric Mean Fold Rise (GMFR) of Anti-Outer Surface Protein A (OspA) Immunoglobulin G (IgG) Concentrations

    Measured: Before the first dose to 1 month after the third VLA15 dose

  3. Sero-Response Rate Based on Anti-Outer Surface Protein A (OspA) Immunoglobulin G (IgG) Concentrations.

    Measured: Before the first dose to 1 month after the third VLA15 dose

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted12 Nov 2025
  2. Study start19 Nov 2025
  3. Primary completion27 Jan 2028 (estimated)
  4. Study completion27 Jan 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
207 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07226882
Sponsor's protocol ID
C4601019
Status last verified
May 2026
First submitted
13 Oct 2025
Last updated
6 May 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing VLA15 in people with Lyme Borreliosis, run by Pfizer at 6 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 6 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 6 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Geometric Mean Concentration (GMC) of Anti-Outer Surface Protein A (OspA) Immunoglobulin G (IgG) (time frame: At 1 month after the fourth VLA15 dose). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07226882.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 May 2026; AzTrials last refreshed its copy on 26 Oct 2026.

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