A Study to Learn About the Safety, Tolerability, and Immunogenicity of a Fifth Dose of 6-Valent OspA-Based Lyme Disease Vaccine
Start Date
4/8/2026
Completion Date
12/4/2026
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.
Detailed 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 Criteria
Age Range: 7 years to No maximum
Interventions
VLA15
Placebo
Conditions
Locations
Northern Light Eastern Maine Medical Center
Bangor, Maine 04401
United States
Northern Light Family Medicine and Residency Center
Bangor, Maine 04401
United States
University of Massachusetts Chan Medical School
Worcester, Massachusetts 01655
United States
Hunterdon Medical Center
Flemington, New Jersey 08822
United States
Smith Allergy and Asthma Specialists
Cortland, New York 13045
United States
Smith Allergy & Asthma Specialists
Horseheads, New York 14845
United States
Altoona Center For Clinical Research
Duncansville, Pennsylvania 16635
United States
Allegheny Health and Wellness Pavilion
Erie, Pennsylvania 16506
United States
Central Erie Primary Care
Erie, Pennsylvania 16508
United States
Preferred Primary Care Physicians, Preferred Clinical Research (Ofc 18)
Pittsburgh, Pennsylvania 15236
United States
Preferred Primary Care Physicians, Preferred Clinical Research - St.Clair
Pittsburgh, Pennsylvania 15243
United States
Robert Packer Hospital
Sayre, Pennsylvania 18840
United States
Frontier Clinical Research, LLC
Scottdale, Pennsylvania 15683
United States
Northeast Clinical Trials Group
Scranton, Pennsylvania 18510
United States
Frontier Clinical Research, LLC
Smithfield, Pennsylvania 15478
United States
Preferred Primary Care Physicians
Uniontown, Pennsylvania 15401
United States
Velocity Clinical Research, Providence
East Greenwich, Rhode Island 02818
United States
The University of Vermont Medical Center Inc.
Burlington, Vermont 05401
United States
Amherst Family Practice, P.C.
Winchester, Virginia 22601
United States
Milestone Research Inc.
London, Ontario N5W 6A2
Canada
Stouffville Medical Research Institute Inc.
Stouffville, Ontario L4A 1H2
Canada
Diex Recherche Inc. Division Sherbrooke
Sherbrooke, Quebec J1L 0H8
Canada