A Study to Learn About the Safety, Tolerability, and Immunogenicity of a Fifth Dose of 6-Valent OspA-Based Lyme Disease Vaccine
Eligible age
7+ yrs
Accepts
All genders
Locations
8 states
Healthy volunteers
Yes
See if you qualify for this study
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About this study
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.
Sponsor: Pfizer
You may qualify if…
- ✓ 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.
You may not qualify if…
- ✕ 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.
Where it's recruiting
Bangor
Worcester
Flemington
Cortland · Horseheads
Duncansville · Erie · Pittsburgh · Sayre …
East Greenwich
Burlington
Winchester
Source: ClinicalTrials.gov · NCT07500506 · last updated 2026-05-06