Den här översättningen är inte klar ännu. Den här sidan är just nu på engelska.

Gå till den engelska sidan

Cure My Disease

Don't miss your cure!

 Log in / Sign up

Pfizer gives lyme vaccine a fifth dose — will it boost protection?

NCT ID NCT07500506

Vaccine Sponsor: Pfizer Source: ClinicalTrials.gov ↗

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now This study
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This study tests whether a fifth dose of Pfizer's Lyme disease vaccine (VLA15) is safe and boosts immunity in people who already received four doses. About 1,700 healthy volunteers aged 7 and older will get either the vaccine or a saltwater shot. Researchers will compare side effects and antibody levels over 12 months.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
VLA15 (Lyme disease vaccine)
What this could lead to
If successful, this could show that a booster dose of the Lyme disease vaccine provides continued protection against Lyme disease.
What could go wrong
This is a Phase 3 trial, but it only tests immune response and safety, not whether the vaccine actually prevents Lyme disease. The vaccine may not work as well in real-world conditions.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Phase 3

Large-scale testing in a bigger group. Usually the last step before a treatment can be approved.

Participants

About 1,712 people

The number the study aims to enrol. It can still change while the study runs.

Started

Apr 2026

Expected to finish

Dec 2026

An estimate. End dates often move.

Lead sponsor

A company

The lead sponsor is a pharmaceutical, biotech, or medical-device company.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

7 years and older

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * 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. * Participants must have received 4 doses of VLA15 in the C4601003 study, and have a V7 blood sample available. Exclusion Criteria: * 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. * Recent or concurrent participation in a separate interventional study. * Staff or direct family of the study site staff and Sponsor.

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for Lyme disease are added.

Vår säkerhetsrekommendation!

Genom att skicka in godkänner du våra Användarvillkor

Conditions

The condition(s) this trial relates to.

Lyme disease prevention target

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Lyme disease

How to take part

Only the study team decides who joins. These are the ways to reach them.

  1. The places running it

    22 sites in 2 countries. The list below names each one and where it is.

  2. The official record

    ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.

    Open the record ↗

  3. A doctor treating you

    A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.

Contacts and locations

Locations

  • Allegheny Health and Wellness Pavilion

    RECRUITING

    Erie, Pennsylvania, 16506, United States

  • Altoona Center For Clinical Research

    RECRUITING

    Duncansville, Pennsylvania, 16635, United States

  • Amherst Family Practice, P.C.

    NOT_YET_RECRUITING

    Winchester, Virginia, 22601, United States

  • Central Erie Primary Care

    RECRUITING

    Erie, Pennsylvania, 16508, United States

  • Diex Recherche Inc. Division Sherbrooke

    RECRUITING

    Sherbrooke, Quebec, J1L 0H8, Canada

  • Frontier Clinical Research, LLC

    RECRUITING

    Scottdale, Pennsylvania, 15683, United States

  • Frontier Clinical Research, LLC

    RECRUITING

    Smithfield, Pennsylvania, 15478, United States

  • Hunterdon Medical Center

    NOT_YET_RECRUITING

    Flemington, New Jersey, 08822, United States

  • Milestone Research Inc.

    NOT_YET_RECRUITING

    London, Ontario, N5W 6A2, Canada

  • Northeast Clinical Trials Group

    RECRUITING

    Scranton, Pennsylvania, 18510, United States

  • Northern Light Eastern Maine Medical Center

    NOT_YET_RECRUITING

    Bangor, Maine, 04401, United States

  • Northern Light Family Medicine and Residency Center

    NOT_YET_RECRUITING

    Bangor, Maine, 04401, United States

  • Preferred Primary Care Physicians

    NOT_YET_RECRUITING

    Uniontown, Pennsylvania, 15401, United States

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

    RECRUITING

    Pittsburgh, Pennsylvania, 15236, United States

  • Preferred Primary Care Physicians, Preferred Clinical Research - St.Clair

    NOT_YET_RECRUITING

    Pittsburgh, Pennsylvania, 15243, United States

  • Robert Packer Hospital

    RECRUITING

    Sayre, Pennsylvania, 18840, United States

  • Smith Allergy & Asthma Specialists

    RECRUITING

    Horseheads, New York, 14845, United States

  • Smith Allergy and Asthma Specialists

    RECRUITING

    Cortland, New York, 13045, United States

  • Stouffville Medical Research Institute Inc.

    NOT_YET_RECRUITING

    Stouffville, Ontario, L4A 1H2, Canada

  • The University of Vermont Medical Center Inc.

    NOT_YET_RECRUITING

    Burlington, Vermont, 05401, United States

  • University of Massachusetts Chan Medical School

    RECRUITING

    Worcester, Massachusetts, 01655, United States

  • Velocity Clinical Research, Providence

    NOT_YET_RECRUITING

    East Greenwich, Rhode Island, 02818, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.