Phase 2 Study Of VLA15, A Vaccine Candidate Against Lyme Borreliosis, In A Healthy Pediatric And Adult Study Population

Trial details

Who runs it

Pfizer

Trial code

NCT04801420

Record updated

15 September 2026

Original description

VLA15-221 is a Phase 2 study, which will be conducted in two parts: Main Study Phase (Part A) and Booster Phase (Part B). The study will compare the safety and immunogenicity of two different primary immunization schedules applying three (Month 0-2-6) or two (Month 0- 6) vaccinations. Within the study, 600 healthy subjects aged 5-65 years will be included. Subjects with a history of Lyme borreliosis (previous infection with Borrelia) as well as Borrelia naïve subjects will be enrolled. Study duration per subject will be a maximum of 50 months per subject.Read full original descriptionShow less

SAFETY AND IMMUNOGENICITY STUDY OF VLA15, A MULTIVALENT RECOMBINANT OSPA BASED VACCINE CANDIDATE AGAINST LYME BORRELIOSIS: A RANDOMIZED, CONTROLLED, OBSERVER-BLIND PHASE 2 STUDY IN A HEALTHY PEDIATRIC AND ADULT STUDY POPULATION

VLA15-221 is a Phase 2 study, which will be conducted in two parts: Main Study Phase (Part A) and Booster Phase (Part B). The study will compare the safety and immunogenicity of two different primary immunization schedules applying three (Month 0-2-6) or two (Month 0- 6) vaccinations. Within the study, 600 healthy subjects aged 5-65 years will be included. Subjects with a history of Lyme borreliosis (previous infection with Borrelia) as well as Borrelia naïve subjects will be enrolled. Study duration per subject will be a maximum of 50 months per subject.

Inclusion: Subject is aged 5 to 65 years at the day of screening (Visit 0); Subject is of good general health; Parent(s)/legal representative(s) and subject understand the study and its procedures, agree to its provisions; for subjects aged 18-65 years: written informed consent prior to any study related procedures; for subjects aged 5-17 years: written informed consent by the subject's legal representative(s), according to local requirements, and written informed assent of the subject, if applicable, prior to any study related procedures; If subject is of childbearing potential: Subject has a negative serum pregnancy test at screening (Visit 0) and agrees to employ adequate birth control measures according to following timelines:; Main Study Phase: duration of entire study; Booster Phase: until 5 months after each booster vaccination (Booster 1 until Month 23, Booster 2 until Month 35 and Booster 3 until Month 47); Subject is willing and able to comply with scheduled visits, treatment plan, and other study procedures; Subject is available for the duration of the study and can be contacted by telephone during study participation.

Exclusion: Subject has a chronic illness related to Lyme borreliosis (LB), an active symptomatic LB, or received treatment for LB within the last 3 months prior to Day 1; Subject received previous vaccination against LB; Subject had a tick bite within 4 weeks prior to Day 1; Subject has a known thrombocytopenia, bleeding disorder, or received anticoagulants in the 3 weeks prior to Day 1; Subject has received an active or passive immunization within 4 weeks prior to Day 1; Subject has received any other registered or non-registered medicinal product in another clinical trial within 4 weeks prior to vaccination at Day 1; Subject has a known or suspected defect of the immune system or received immuno-suppressive therapy within 4 weeks prior to Day 1; Subject has donated or plans to donate blood or blood-derived products 4 weeks prior to Day 1; Subject has a medical history of or currently has a clinically relevant disease; Subject has a medical history of or currently has a neuro- inflammatory or autoimmune disease; Subject has a history of anaphylaxis of unknown cause or severe allergic reactions of unknown cause or has a known hypersensitivity or allergic reactions to one of the components of the vaccine; Subject had any malignancy in the past 5 years; Subject has any condition that may compromise its well-being, might interfere with evaluation of study endpoints, or would limit the subject's ability to complete the study; Subject is pregnant, has plans to become pregnant during the course of the study or is lactating at the time of enrollment; Subject is in a dependent relationship with the sponsor/investigator.

ClinicalTrials.gov NCT04801420