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

August 19, 2026 updated by: Pfizer

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

VLA15-221 is a randomized, observer-blind, placebo controlled, multicenter Phase 2 study, which is set up in two parts: Main Study Phase (Part A) and Booster Phase (Part B). In Part A 600 subjects aged 5-65 years will be enrolled 1:1:1 into three groups: Group 1 will be vaccinated with VLA15 at Month 0-2-6, Group 2 will be vaccinated with VLA15 at Month 0-6 and with placebo at Month 2 and Group 3 will be vaccinated with placebo at Month 0-2-6. In Part B all eligible subjects will receive booster injections with VLA15 or placebo at Month 18, 30 and 42.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
625

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Connecticut
      • Bridgeport, Connecticut, United States, 06606
        • New England Research Associates
      • Stamford, Connecticut, United States, 06905
        • Stamford Therapeutics Consortium
      • Waterbury, Connecticut, United States, 06708
        • Chase Medical Research, LLC
      • Waterbury, Connecticut, United States, 06708
        • Pediatric Associates of Conn. PC
    • Minnesota
      • Minneapolis, Minnesota, United States, 55402
        • Clinical Research Institute, Inc.
    • New Jersey
      • East Orange, New Jersey, United States, 07018
        • Foundation Pediatrics
      • Irvington, New Jersey, United States, 07111
        • Med Clinical Research Partners, LLC
    • New York
      • Binghamton, New York, United States, 13905
        • Meridian Clinical Research LLC
      • Rochester, New York, United States, 14609
        • Rochester Clinical Research, Inc.
      • Staten Island, New York, United States, 10314
        • Richmond Behavioral Associates
      • The Bronx, New York, United States, 10467
        • Advantage Clinical Trials
    • Ohio
      • Cleveland, Ohio, United States, 44122
        • Velocity Clinical Research, Inc.
    • Pennsylvania
      • Erie, Pennsylvania, United States, 16506
        • Allegheny Health and Wellness Pavilion
      • Erie, Pennsylvania, United States, 16508
        • Liberty Family Practice
      • Fort Washington, Pennsylvania, United States, 19034
        • Lockman & Lubell Pediatric Associates
    • Rhode Island
      • Providence, Rhode Island, United States, 02906
        • The Miriam Hospital
      • Providence, Rhode Island, United States, 02903
        • Rhode Island Hospital
      • Providence, Rhode Island, United States, 02903
        • Hasbro Children's Hospital
      • Warwick, Rhode Island, United States, 02886
        • Velocity Clinical Research Providence

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

5 years to 65 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 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 Criteria:

  • 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 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 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 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 is pregnant, has plans to become pregnant during the course of the study or is lactating at the time of enrollment;
  • Subject has donated or plans to donate blood or blood-derived products 4 weeks prior to Day 1;
  • 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 in a dependent relationship with the sponsor/investigator

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Part A+B - Group 1
Part A: VLA15 at Month 0, 2 and 6 Part B: VLA15 at Month 18, 30 and 42
Biological: VLA15
a multivalent recombinant Outer Surface Protein A (OspA) based vaccine candidate
Experimental: Part A+B - Group 2
Part A: VLA15 at Month 0 and 6, placebo at Month 2 Part B: VLA15 at Month 18, 30 and 42
Biological: VLA15
a multivalent recombinant Outer Surface Protein A (OspA) based vaccine candidate
Biological: Placebo
PBS (Phosphate Buffered Saline)
Placebo Comparator: Part A+B - Group 3
Part A: Placebo at Month 0, 2 and 6 Part B: Placebo at Month 18, 30 and 42
Biological: Placebo
PBS (Phosphate Buffered Saline)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Percentage of Participants With Solicited Local and Solicited Systemic Adverse Events (AEs) Within 7 Days After Vaccination 1
Time Frame: From Day 1 to Day 7 after vaccination 1 at Month 0
Participants or their legal guardians were required to record any solicited local and systemic AEs in the electronic diary. Solicited symptoms were pre-defined symptoms which were collected via an electronic diary. Solicited local AEs included pain, tenderness, erythema/redness meeting grading scale (MGS), swelling MGS and induration/hardening MGS. Solicited systemic AEs included headache, muscle pain, joint pain, nausea, vomiting, fatigue and fever.
From Day 1 to Day 7 after vaccination 1 at Month 0
Percentage of Participants With Solicited Local and Solicited Systemic AEs Within 7 Days After Vaccination 2
Time Frame: From Day 1 to Day 7 after vaccination 2 at Month 2
Participants or their legal guardians were required to record any solicited local and systemic AEs in the electronic diary. Solicited symptoms were pre-defined symptoms which were collected via an electronic diary. Solicited local AEs included pain, tenderness, erythema/redness MGS, swelling MGS and induration/hardening MGS. Solicited systemic AEs included headache, muscle pain, joint pain, nausea, vomiting, fatigue and fever.
From Day 1 to Day 7 after vaccination 2 at Month 2
Percentage of Participants With Solicited Local and Solicited Systemic AEs Within 7 Days After Vaccination 3
Time Frame: From Day 1 to Day 7 after vaccination 3 at Month 6
Participants or their legal guardians were required to record any solicited local and systemic AEs in the electronic diary. Solicited symptoms were pre-defined symptoms which were collected via an electronic diary. Solicited local AEs included pain, tenderness, erythema/redness MGS, swelling MGS and induration/hardening MGS. Solicited systemic AEs included headache, muscle pain, joint pain, nausea, vomiting, fatigue and fever.
From Day 1 to Day 7 after vaccination 3 at Month 6
Percentage of Participants With Solicited Local and Solicited Systemic AEs Within 7 Days After Any Vaccination During the Main Study Phase
Time Frame: From Day 1 to Day 7 after any vaccination 1, 2 or 3 at Month 0, 2 and 6, respectively
Participants or their legal guardians were required to record any solicited local and systemic AEs in the electronic diary. Solicited symptoms were pre-defined symptoms which were collected via an electronic diary. Solicited local AEs included pain, tenderness, erythema/redness MGS, swelling MGS and induration/hardening MGS. Solicited systemic AEs included headache, muscle pain, joint pain, nausea, vomiting, fatigue and fever.
From Day 1 to Day 7 after any vaccination 1, 2 or 3 at Month 0, 2 and 6, respectively
Geometric Mean Titers (GMTs) for Immunoglobulin G (IgG) Against Each Outer Surface Protein A (OspA) Serotype (ST1 to ST6) at Day 208 During the Main Study Phase
Time Frame: At Day 208 (Month 7)
GMTs for IgG against each OspA serotype ST1 to ST6, determined by an IgG binding assay at Day 208 was presented in this outcome measure.
At Day 208 (Month 7)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Percentage of Participants With Solicited Local and Solicited Systemic AEs Within 7 Days After Vaccination 1 Booster Dose
Time Frame: From Day 1 to Day 7 after vaccination 1 booster dose at Month 18
Participants or their legal guardians were required to record any solicited local and systemic AEs in the electronic diary. Solicited symptoms were pre-defined symptoms which were collected via an electronic diary. Solicited local AEs included pain, tenderness, erythema/redness MGS, swelling MGS and induration/hardening MGS. Solicited systemic AEs included headache, muscle pain, joint pain, nausea, vomiting, fatigue and fever.
From Day 1 to Day 7 after vaccination 1 booster dose at Month 18
Percentage of Participants With Solicited Local and Solicited Systemic AEs Within 7 Days After Vaccination 2 Booster Dose
Time Frame: From Day 1 to Day 7 after vaccination 2 booster dose at Month 30
Participants or their legal guardians were required to record any solicited local and systemic AEs in the electronic diary. Solicited symptoms were pre-defined symptoms which were collected via an electronic diary. Solicited local AEs included pain, tenderness, erythema/redness MGS, swelling MGS and induration/hardening MGS. Solicited systemic AEs included headache, muscle pain, joint pain, nausea, vomiting, fatigue and fever.
From Day 1 to Day 7 after vaccination 2 booster dose at Month 30
Percentage of Participants With Solicited Local and Solicited Systemic AEs Within 7 Days After Vaccination 3 Booster Dose
Time Frame: From Day 1 to Day 7 after vaccination 3 booster dose at Month 42
Participants or their legal guardians were required to record any solicited local and systemic AEs in the electronic diary. Solicited symptoms were pre-defined symptoms which were collected via an electronic diary. Solicited local AEs included pain, tenderness, erythema/redness MGS, swelling MGS and induration/hardening MGS. Solicited systemic AEs included headache, muscle pain, joint pain, nausea, vomiting, fatigue and fever.
From Day 1 to Day 7 after vaccination 3 booster dose at Month 42
Percentage of Participants With Serious Adverse Events (SAEs)
Time Frame: From Day 1 of vaccination 1 up to 6 months following the last booster dose (up to Month 48)
A SAE was any untoward medical occurrence that at any dose: resulted in death; required inpatient hospitalization or prolongation of existing hospitalization; was life-threatening; resulted in persistent or significant disability/incapacity; was a congenital anomaly/birth defect; was another medically important condition.
From Day 1 of vaccination 1 up to 6 months following the last booster dose (up to Month 48)
Percentage of Participants With Adverse Events of Special Interest (AESIs)
Time Frame: From Day 1 of vaccination 1 up to 6 months following the last booster dose (up to Month 48)
An AESI (serious or non-serious) was one of scientific and medical concern specific to the sponsor's product or program, for which ongoing monitoring and rapid communication by the investigator to the sponsor were appropriate.
From Day 1 of vaccination 1 up to 6 months following the last booster dose (up to Month 48)
Percentage of Participants With Unsolicited AE
Time Frame: Up to 28 Days after vaccination 1, 2 or 3 at Month 0, 2 and 6, respectively, and up to 28 Days after vaccination 1, 2 or 3 booster dose at Month 18, 30 and 42, respectively
An AE was any untoward medical occurrence in a participant administered an investigational product, whether or not related to this treatment. Unsolicited AEs were defined as any solicited local or systemic AE if it had an onset date more than 6 days after vaccination or any other symptom or untoward medical event.
Up to 28 Days after vaccination 1, 2 or 3 at Month 0, 2 and 6, respectively, and up to 28 Days after vaccination 1, 2 or 3 booster dose at Month 18, 30 and 42, respectively
Percentage of Participants With SAEs, AESIs, Solicited and Unsolicited AEs Stratified by Age Group
Time Frame: SAEs & AESIs: From Day 1 of vaccination up to Month 48; Solicited AEs: from Day 1 to Day 7 after vaccination 1, 2, 3, 4, 5 and 6; Unsolicited AEs: up to 28 Days after vaccination 1, 2, 3, 4, 5 and 6
Percentage of participants with SAEs, AESIs, solicited and unsolicited AEs stratified by age group 5-11, 12-17 and 18-65 years were reported. SAE: any untoward medical occurrence that at any dose: resulted in death; required inpatient hospitalization or prolongation of existing hospitalization; was life-threatening; resulted in persistent or significant disability/incapacity; was a congenital anomaly/birth defect; was another medically important condition. AESI: scientific and medical concern specific to the sponsor's product or program. Solicited AE: predefined reactions at injection site or systemic reactions after each vaccination. Unsolicited AEs: any solicited local or systemic AE if it had an onset date more than 6 days after vaccination or any other symptom or untoward medical event.
SAEs & AESIs: From Day 1 of vaccination up to Month 48; Solicited AEs: from Day 1 to Day 7 after vaccination 1, 2, 3, 4, 5 and 6; Unsolicited AEs: up to 28 Days after vaccination 1, 2, 3, 4, 5 and 6
GMTs for IgG Against Each OspA Serotype (ST1 to ST6) at Baseline, Days 85, 180, 365 and Month 18
Time Frame: Baseline; Days 85, 180 and 365; Month 18
GMTs for IgG against each OspA serotype ST1 to ST6, determined by an IgG binding assay were evaluated.
Baseline; Days 85, 180 and 365; Month 18
Seroconversion Rate (SCR) at Days 85, 180, 208, 365 and Month 18
Time Frame: Days 85, 180, 208 and 365; Month 18
Seroconversion for enzyme linked immunosorbent assay (ELISA) was defined as a change from seronegative at baseline to seropositive at a measured time point. For participants who were OspA seropositive at baseline, seroconversion was defined as a greater than or equal to (>=) 4-fold rise in IgG antibody titer from baseline. SCR was percentage of participants with seroconversion reported for each OspA serotype specific IgG ST1 to ST6, as determined by ELISA.
Days 85, 180, 208 and 365; Month 18
Geometric Mean of the Fold Rise (GMFR) for IgG When Compared to Baseline Against Each OspA Serotype (ST1 to ST6) at Days 85 and 208
Time Frame: Days 85 and 208
GMFR for IgG when compared to baseline against each OspA serotype ST1 to ST6, determined by IgG binding assay at Day 85 and Day 208 were evaluated.
Days 85 and 208
GMTs for IgG Against Each OspA Serotype (ST1 to ST6) Stratified by Age Group at Baseline, Days 85, 180, 194, 365 and Month 18
Time Frame: Baseline; Days 85, 180, 194 (18 to 65 years only) and 365; Month 18
GMTs for IgG against each OspA serotype ST1 to ST6, determined by an IgG binding assay stratified by age group (5-11, 12-17 and 18-65 years) were evaluated. Day 194 data was reported for adult participants only as pre-specified in protocol.
Baseline; Days 85, 180, 194 (18 to 65 years only) and 365; Month 18
SCR Stratified by Age Group at Days 85, 180, 194, 208, 365 and Month 18
Time Frame: Days 85, 180, 194 (18 to 65 years only), 208 and 365; Month 18
Seroconversion for ELISA was defined as a change from seronegative at baseline to seropositive at a measured time point. For participants who were OspA seropositive at baseline, seroconversion was defined as a >=4-fold rise in IgG antibody titer from baseline. SCR was percentage of participants with seroconversion reported for each OspA serotype specific IgG ST1 to ST6, as determined by ELISA. Day 194 data was reported for adult participants only as pre-specified in protocol.
Days 85, 180, 194 (18 to 65 years only), 208 and 365; Month 18
GMFR for IgG When Compared to Baseline Against Each OspA Serotype (ST1 to ST6) Stratified by Age Group at Days 85 and 208
Time Frame: Days 85 and 208
GMFR for IgG when compared to baseline against each OspA serotype ST1 to ST6, stratified by age group (5-11, 12-17 and 18-65 years) determined by IgG binding assay at Day 85 and Day 208 were evaluated.
Days 85 and 208
GMTs for IgG Against Each OspA Serotype (ST1 to ST6) at Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
Time Frame: Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
GMTs for IgG against each OspA serotype ST1 to ST6, determined by an IgG binding assay were evaluated.
Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
SCR at Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
Time Frame: Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
Seroconversion for ELISA was defined as a change from seronegative at baseline to seropositive at a measured time point. For participants who were OspA seropositive at baseline, seroconversion was defined as a >=4-fold rise in IgG antibody titer from baseline. SCR was percentage of participants with seroconversion reported for each OspA serotype specific IgG ST1 to ST6, as determined by ELISA.
Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
GMFR for IgG Against Each OspA Serotype (ST1 to ST6) at Months 19, 31 and 43 During the Booster Phase
Time Frame: Months 19, 31 and 43
GMFRs for IgG were determined by IgG binding assay for each OspA serotype (ST1-ST6) at Months 19, 31, and 43 relative to the corresponding pre-booster timepoints Months 18, 30, and 42, respectively.
Months 19, 31 and 43
GMTs for IgG Against Each OspA Serotype (ST1 to ST6) Stratified by Age Group at Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
Time Frame: Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
GMTs for IgG against each OspA serotype ST1 to ST6, determined by an IgG binding assay stratified by age group (5-11, 12-17 and 18-65 years) were evaluated.
Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
SCR Stratified by Age Group at Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
Time Frame: Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
Seroconversion for ELISA was defined as a change from seronegative at baseline to seropositive at a measured time point. For participants who were OspA seropositive at baseline, seroconversion was defined as a >=4-fold rise in IgG antibody titer from baseline. SCR was percentage of participants with seroconversion reported for each OspA serotype specific IgG ST1 to ST6, as determined by ELISA.
Months 18, 19, 23, 26, 30, 31, 39, 42, 43 and 48
GMFR for IgG Against Each OspA Serotype (ST1 to ST6) Stratified by Age Group at Months 19, 31 and 43 During the Booster Phase
Time Frame: Months 19, 31 and 43
GMFRs for IgG were determined by IgG binding assay for each OspA serotype (ST1-ST6), stratified by age group (5-11, 12-17 and 18-65 years) at Months 19, 31, and 43 relative to the corresponding pre-booster timepoints Months 18, 30, and 42, respectively.
Months 19, 31 and 43

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Pfizer

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Valneva Austria GmbH

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 8, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 25, 2022

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 2, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 8, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 15, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 17, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 19, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • VLA15-221
  • C4601008 (Other Identifier: Alias Study Number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

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