Image

A Study to Learn About the Safety, Tolerability, and Immunogenicity of a Fifth Dose of 6-Valent OspA-Based Lyme Disease Vaccine

A Study to Learn About the Safety, Tolerability, and Immunogenicity of a Fifth Dose of 6-Valent OspA-Based Lyme Disease Vaccine

Recruiting
7 years and older
All
Phase 3

Powered by AI

Overview

The purpose of this study is to learn about the safety effects of the Lyme disease vaccine (called VLA15), and its ability to protect people from Lyme disease after a 5th dose of the vaccine.

This study is seeking participants who:

  • are generally healthy and 7 years of age and older,
  • have already been vaccinated with 4 doses of VLA15 (from the VALOR study), and have blood sample taken post dose 4.
  • are not currently taking, or haven't recently taken, medicines like chemotherapy, blood products, or blood thinners.
  • 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 1 dose through a shot in the upper arm, either VLA15 or saline shot (saltwater).

The study will compare the experiences of people receiving the study vaccine or saltwater shot.

Participants will take part in this study for about 12 months. During this time, they will have 4 planned clinic visits. The clinic visits may include having a health check, giving a small amount of blood and getting the study vaccine or saltwater as a shot at the first visit.

Description

A Phase 3, Randomized, Placebo-Controlled, Double-Blinded Study to Evaluate the Safety, Tolerability, and Immunogenicity of a Fifth Dose of 6-Valent OspA-Based Lyme Disease Vaccine, VLA15, in Healthy Participants ≥7 Years of Age

Participants will be randomized in a 5:1 ratio to receive either one dose of VLA15 or placebo (saline) at the first visit. 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 1712 participants will be enrolled in the study.

Healthy individuals 7 years of age and older who have received 4 prior doses of active VLA15 from the C4601003 study, have a blood sample taken post dose 4, 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.

Eligibility

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.

Study details
    Lyme Disease

NCT07500506

Pfizer

13 May 2026

Step 1 Get in touch with the nearest study center
We have submitted the contact information you provided to the research team at {{SITE_NAME}}. A copy of the message has been sent to your email for your records.
Would you like to be notified about other trials? Sign up for Patient Notification Services.
Sign up

Send a message

Enter your contact details to connect with study team

Investigator Avatar

Primary Contact

  Other languages supported:

First name*
Last name*
Email*
Phone number*
Other language

FAQs

Learn more about clinical trials

What is a clinical trial?

A clinical trial is a study designed to test specific interventions or treatments' effectiveness and safety, paving the way for new, innovative healthcare solutions.

Why should I take part in a clinical trial?

Participating in a clinical trial provides early access to potentially effective treatments and directly contributes to the healthcare advancements that benefit us all.

How long does a clinical trial take place?

The duration of clinical trials varies. Some trials last weeks, some years, depending on the phase and intention of the trial.

Do I get compensated for taking part in clinical trials?

Compensation varies per trial. Some offer payment or reimbursement for time and travel, while others may not.

How safe are clinical trials?

Clinical trials follow strict ethical guidelines and protocols to safeguard participants' health. They are closely monitored and safety reviewed regularly.
Add a private note
  • abc Select a piece of text.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.