CI

At a glance

ClinicalIndex Comparison Record
Phase 2Completed· 625 enrolled
Drug / intervention
VLA15 +1 morebiological
Likely dose
Not stated in record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT04801420
NCT04801420Phase 2Completed

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

Pfizer·interventional·Posted Mar 17, 2021·Updated May 19, 2026

In Brief

A Phase 2 clinical trial evaluating VLA15 and Placebo for Lyme Borreliosis. Completed, enrolled 625 participants across 19 sites.

Detailed Summary

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.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesUnited States

Timeline

Phase 2CompletedFinished
20222023202420252026
First PostedMar 17, 2021
Enrollment StartMar 8, 2021
Primary CompletionMar 25, 2022
Study CompletionJul 2, 2025
TodayJul 2, 2026
Enrollment to primary: 1.0 yearsPosted 5.3 years ago

Interventions

VLA15biological

a multivalent recombinant Outer Surface Protein A (OspA) based vaccine candidate

Placebobiological

PBS (Phosphate Buffered Saline)