Recruiting
Phase 3

VLA15

Sponsor:

Pfizer

Code:

NCT07500506

Conditions

Lyme Disease

Eligibility Criteria

Sex: All

Age: 7+

Healthy Volunteers: Accepted

Interventions

VLA15

Placebo

Study Details

Brief summary:

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.

Conditions

Lyme Disease

Study ID

NCT07500506

Start date

Apr 8, 2026

Status verified date

May, 2026

Completion date

Dec 4, 2026

Anticipated

Primary completion date

Dec 4, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 7+

Healthy Volunteers: Accepted

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 Design

Enrollment

1712 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: VLA15-1A

Participants will receive a single injection in the muscle (IM) of VLA15 at Visits 1, two years after their 4th dose of VLA15

placebo comparator: VLA15-1B

Participants will receive a single injection in the muscle (IM) of Saline at Visits 1, two years after their 4th dose of VLA15

experimental: VLA15-2A

Participants will receive a single injection in the muscle (IM) of VLA15 at Visits 1, one year after their 4th dose of VLA15

placebo comparator: VLA15-2B

Participants will receive a single injection in the muscle (IM) of saline at Visits 1, one year after their 4th dose of VLA15

Interventions

VLA15

VLA15 injection IM

Placebo

Saline Injection

Primary outcome measure

  • Percentage of participants reporting prespecified local reactions [ Time Frame: Within 7 days following each study intervention administration ]
  • Percentage of participants reporting prespecified systemic events [ Time Frame: Within 7 days following each study intervention administration ]
  • Percentage of participants reporting adverse events (AEs) [ Time Frame: Through 1 month following study intervention administration ]
  • Percentage of participants reporting newly diagnosed chronic medical conditions (NDCMCs) [ Time Frame: Through study completion, up to approximately 12 months. ]
  • Percentage of participants reporting serious adverse events (SAEs) [ Time Frame: Through study completion, up to approximately 12 months. ]
  • Geometric mean ratio (GMR) of anti-OspA IgG concentrations for each serotype (ST1-ST6) [ Time Frame: At 1 month after completion of Dose 5 ]
  • Sero-response of anti-OspA IgG concentrations for each serotype (ST1-ST6). [ Time Frame: At 1 month after completion of Dose 5 ]

Central Contacts and Locations

Central contacts

Pfizer CT.gov Call Center

1-800-718-1021ClinicalTrials.gov_Inquiries@pfizer.com

Locations

University of Massachusetts Chan Medical School

Recruiting

Worcester, Massachusetts, United States, 01655

Smith Allergy and Asthma Specialists

Recruiting

Cortland, New York, United States, 13045

Smith Allergy & Asthma Specialists

Recruiting

Horseheads, New York, United States, 14845

Altoona Center For Clinical Research

Recruiting

Duncansville, Pennsylvania, United States, 16635

Allegheny Health and Wellness Pavilion

Recruiting

Erie, Pennsylvania, United States, 16506

Central Erie Primary Care

Recruiting

Erie, Pennsylvania, United States, 16508

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

Recruiting

Pittsburgh, Pennsylvania, United States, 15236

Robert Packer Hospital

Recruiting

Sayre, Pennsylvania, United States, 18840

Frontier Clinical Research, LLC

Recruiting

Scottdale, Pennsylvania, United States, 15683

Northeast Clinical Trials Group

Recruiting

Scranton, Pennsylvania, United States, 18510

Frontier Clinical Research, LLC

Recruiting

Smithfield, Pennsylvania, United States, 15478

Diex Recherche Inc. Division Sherbrooke

Recruiting

Sherbrooke, Quebec, Canada, J1L 0H8

More Information

Sponsor

Pfizer

Last update posted

May 6, 2026

Last verified

May, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Pfizer on 2026-05-06.