A Study on the Immune Response and Safety of an Investigational Chickenpox Vaccine and a Marketed Measles, Mumps and Rubella Vaccine When Administered as Intramuscular Injection to Healthy Children 12 to 15 Months of Age

May 27, 2026 updated by: GlaxoSmithKline

A Phase 3a, Open-Label, Randomized, Controlled Study to Evaluate the Immunogenicity and Safety of Intramuscular Administration of an Investigational Varicella Vaccine and Priorix Compared With Subcutaneous Administration of Varivax and Priorix, When Given as a First Dose to Healthy Children 12 to 15 Months of Age

This study aims to assess the immune response and safety of GSK's candidate chickenpox and marketed MMR vaccines when given to children 12 to 15 months of age via a muscle injection. It compares the GSK vaccines to Merck's chickenpox vaccine, administered just under the skin. Additionally, the study will evaluate the immune response and safety of giving the GSK vaccines along with other childhood vaccines through a muscle injection.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

911

Phase

  • Phase 3

Contacts and Locations

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

Study Contact

Study Contact Backup

Study Locations

  • Belgium
      • Alken, Belgium, 3570
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Hilde Bollen
  • Estonia
      • Tartu, Estonia, 50106
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Airi Poder
  • Greece
      • Athens, Greece, 11527
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Maria Tsolia
      • Athens, Greece, 115 27
        • Withdrawn
        • GSK Investigational Site
      • Thessaloniki, Greece, 54642
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Elias Iosifidis
  • Poland
      • Trzebnica, Poland, 55-100
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Henryk Szymanski
        • Contact:
        • Contact:
  • Romania
      • Brasov, Romania, 500283
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Dana Baraghin
      • Calarasi, Romania, 910160
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Alexandra Carmen Cara
  • Thailand
      • Chiang Mai, Thailand, 50200
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Peninnah Oberdorfer
  • United States
    • Arizona
      • Tucson, Arizona, United States, 85704
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Dena Petersen
    • California
      • Huntington Park, California, United States, 90255
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Albert Nassir
      • Sherman Oaks, California, United States, 91403
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Dmitriy Romanenko
    • Florida
      • Coral Gables, Florida, United States, 33134
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Ivo Alonso
      • Miami Lakes, Florida, United States, 33014
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Angel Rico
      • Tampa, Florida, United States, 33612
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Michele Johnson Towson
    • Idaho
      • Idaho Falls, Idaho, United States, 83404
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Boyd Southwick
    • Ohio
      • Dayton, Ohio, United States, 45414
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Julie Shepard
    • Texas
      • Houston, Texas, United States, 77584
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Yvette Poindexter
      • Lewisville, Texas, United States, 75067
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Asgar Dudhbhai
      • Mansfield, Texas, United States, 76063
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Keithlee Dolinta
      • Pharr, Texas, United States, 78577
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Belinda Jordan
    • Virginia
      • Richmond, Virginia, United States, 23294
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • John Scott
        • Contact:
        • Contact:

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

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Participant's parent(s)/ Legally acceptable representatives (LAR[s]), who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of the eDiaries, return for follow-up visits).
  • Written or witnessed/thumb printed informed consent obtained from the participant's parent(s)/LAR(s) prior to performance of any study-specific procedure.
  • Healthy participants as established by medical history and clinical examination before entering into the study.
  • A male or female between, and including, 12 to 15 months of age (i.e., from the day of 1-year birthday until the day before 16 months of age) at the time of the administration of study interventions.

  • Only for children in countries where PCV is recommended at 12 to 15 months of age as per national immunization schedule and provided as part of the study interventions:

    • Participant who previously received the primary series of PCV in the first year of life with last dose at least 60 days prior to the administration of study intervention.

Exclusion Criteria:

  • History of any reaction or hypersensitivity likely to be exacerbated by any component of the study interventions including hypersensitivity to neomycin or gelatin.
  • Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
  • Hypersensitivity to latex.
  • Major congenital defects, as assessed by the investigator.
  • Recurrent history of uncontrolled neurological disorders or seizures.
  • History of measles, mumps, rubella, or varicella disease.
  • Active untreated tuberculosis.
  • Participants with bleeding disorders (e.g., thrombocytopenia or any coagulation disorder).
  • Condition that in the judgment of the investigator would make intramuscular injection unsafe.
  • Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study.

Prior/Concomitant therapy

  • Use of any investigational or non-registered product (drug, vaccine or invasive medical device) other than the study interventions during the period beginning 30 days before the dose of study interventions administration (Day -29 to Day 1), or their planned use during the study period.

  • Chronic administration of immune-modifying drugs (defined as more than 14 consecutive days in total) and/or planned use of long-acting immune modifying treatments at any time up to the end of the study.

    - Up to 90 days prior to the study intervention administration:

  • For corticosteroids, this will mean prednisone equivalent >=0.5 mg/kg/day with maximum of 20 mg/day for pediatric participants. Inhaled and topical steroids are allowed.

  • Administration of immunoglobulins and/or any blood products or plasma derivatives.

    - Up to 180 days prior to study interventions administration: long acting immune-modifying drugs including among others immunotherapy (e.g., tumor necrosis factor-inhibitors), monoclonal antibodies (except the ones not interfering with the immune response to the study vaccines, e.g., nirsevimab), antitumoral medication.

  • Previous vaccination against measles, mumps, and rubella.
  • Previous vaccination against varicella virus.
  • Previous vaccination against hepatitis A virus.
  • Only for children in countries where PCV is recommended at 12 to 15 months of age as per national immunization schedule and provided as part of the study interventions, participant who previously received a booster dose of any PCV.

Prior/Concurrent clinical study experience

• Concurrently participating in another clinical study, at any time during the study period, in which the participant has been or will be exposed to an investigational or a non-investigational intervention (drug/invasive medical device).

Other exclusion criteria

  • Any study personnel or their immediate dependents, family, or household members.
  • Child in care.
  • Participants with the following high-risk individuals in their household: • Immunocompromised individuals.
  • Pregnant women without documented history of varicella.
  • Newborn infants of mothers without documented history of varicella.
  • Newborn infants born <28 weeks of gestation

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: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: VNS+ MMR Vaccine
Participants receive 1 dose of the candidate varicella vaccine (VNS vaccine), 1 dose of a measles, mumps, and rubella (MMR) vaccine, 1 dose of a hepatitis A virus (HAV vaccine), and 1 dose of PCV (either PCV 13 or Vaxneuvance or PCV 20) on Day 1.
Biological: Hepatitis A vaccine
Hepatitis A vaccine co-administered intramuscularly.
Biological: PCV (pneumococcal conjugate vaccine) 13
The 13-valent pneumococcal conjugate vaccine co-administered intramuscularly. In some countries PCV will only be administered depending on the availability, country's registration status and national recommendations for pneumococcal vaccination at the time of study conduct.
Biological: PCV 20
The 20-valent pneumococcal conjugate vaccine co-administered intramuscularly. In some countries PCV will only be administered depending on the availability, country's registration status and national recommendations for pneumococcal vaccination at the time of study conduct.
Biological: Candidate varicella vaccine
Investigational varicella vaccine administered intramuscularly.
Biological: MMR vaccine
MMR vaccine administered subcutaneously or intramuscularly.
Biological: Vaxneuvance
The Vaxneuvance (15-valent pneumococcal conjugate vaccine) co-administered intramuscularly. In some countries Vaxneuvancewill only be administered depending on the availability, country's registration status and national recommendations for pneumococcal vaccination at the time of study conduct.
Active Comparator: VV+MMR Vaccine
Participants receive 1 dose of a Marketed varicella vaccine (VV), 1 dose of a MMR vaccine, 1 dose of a HAV vaccine, and 1 dose of PCV (either PCV 13 or Vaxneuvance or PCV 20) on Day 1.
Biological: Hepatitis A vaccine
Hepatitis A vaccine co-administered intramuscularly.
Biological: PCV (pneumococcal conjugate vaccine) 13
The 13-valent pneumococcal conjugate vaccine co-administered intramuscularly. In some countries PCV will only be administered depending on the availability, country's registration status and national recommendations for pneumococcal vaccination at the time of study conduct.
Biological: PCV 20
The 20-valent pneumococcal conjugate vaccine co-administered intramuscularly. In some countries PCV will only be administered depending on the availability, country's registration status and national recommendations for pneumococcal vaccination at the time of study conduct.
Biological: Marketed varicella vaccine
Marketed varicella vaccine administered subcutaneously.
Biological: MMR vaccine
MMR vaccine administered subcutaneously or intramuscularly.
Biological: Vaxneuvance
The Vaxneuvance (15-valent pneumococcal conjugate vaccine) co-administered intramuscularly. In some countries Vaxneuvancewill only be administered depending on the availability, country's registration status and national recommendations for pneumococcal vaccination at the time of study conduct.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of participants with seroresponse to Varicella Zoster Virus (VZV) anti- glycoprotein E (gE) Immunoglobulin (IgG)
Time Frame: At Day 43
The seroresponse rate is defined as the percentage of participants for whom the post-vaccination Day 43 anti VZV gE IgG concentration is above the seroresponse threshold.
At Day 43
Geometric Mean Concentration (GMC) of anti-VZV gE IgG
Time Frame: At Day 43
Concentrations of anti-VZV gE IgG are presented as GMC and expressed in milli-international units per milliliter (mIU/mL) for each group.
At Day 43
Percentage of participants with seroresponse to MMR antigens
Time Frame: At Day 43
The seroresponse rate is defined as the percentage of participants for whom the post-vaccination Day 43 anti-measles, mumps, and rubella antibody concentrations are above the seroresponse threshold.
At Day 43
GMC of Anti-measles antibodies
Time Frame: At Day 43
At Day 43
GMC of Anti-mumps antibodies
Time Frame: At Day 43
At Day 43
GMC of Anti-rubella antibodies
Time Frame: At Day 43
At Day 43

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of participants reporting medically attended AEs (MAAE) post-dose of study interventions administration
Time Frame: Day 1 (post-dose) to Day 181 (Study end)
A MAAE is an AE for which the participant received medical attention including any symptom or illness requiring hospitalization, or an emergency room visit, or visit to/by a healthcare professional.
Day 1 (post-dose) to Day 181 (Study end)
Percentage of participants reporting Serious AEs (SAEs) post-dose of study interventions administration
Time Frame: Day 1 (post-dose) to Day 181 (Study end)
A SAE is an AE which results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in disability/incapacity, or other situations that are considered serious per medical or scientific judgment.
Day 1 (post-dose) to Day 181 (Study end)
Percentage of participants with seroresponse to MMR antigens with a reduced non-inferiority margin
Time Frame: At Day 43
At Day 43
Percentage of participants reporting each solicited administration site events post-dose of investigational VNS vaccine or VV administration
Time Frame: Day 1 (post-dose) to Day 4
Solicited administration site events include injection site redness, pain, and swelling.
Day 1 (post-dose) to Day 4
Percentage of participants reporting each solicited administration site events post-dose of MMR vaccine administration
Time Frame: Day 1 (post-dose) to Day 4
Solicited administration site events include injection site redness, pain and swelling.
Day 1 (post-dose) to Day 4
Percentage of participants reporting each solicited systemic events post-dose of study interventions administration
Time Frame: Day 1 (post-dose) to Day 15
Solicited systemic events include drowsiness, loss of appetite and irritability.
Day 1 (post-dose) to Day 15
Percentage of participants reporting each solicited systemic event in terms of fever post-dose of study interventions administration
Time Frame: Day 1 (post-dose) to Day 22
Fever is defined as temperature greater than or equal (>=) 38.0 degrees Celsius (°C) regardless of the location of measurement (the preferred location for measuring temperature is the axilla).
Day 1 (post-dose) to Day 22
Percentage of participants reporting each solicited administration site events post-dose of study interventions administration
Time Frame: Day 1 (post-dose) to Day 43
Solicited administration site events include injection site varicella-like rash.
Day 1 (post-dose) to Day 43
Percentage of participants reporting each solicited systemic events post-dose of study interventions administration
Time Frame: Day 1 (post-dose) to Day 43
Solicited systemic events includes varicella-like rash (non-injection site), measles/rubella-like rash, and general rash (not varicella like and not measles/rubella-like).
Day 1 (post-dose) to Day 43
Percentage of participants reporting unsolicited Adverse Events (AEs) post-dose of study interventions administration
Time Frame: Day 1 (post-dose) to Day 43
Unsolicited AEs include any AE reported in addition to solicited events during the study, or any "solicited" symptoms with onset outside of the specified period of follow-up for solicited symptoms, are assessed for each group after the administration of all vaccines. Unsolicited AEs include nonserious and serious AEs.
Day 1 (post-dose) to Day 43
Percentage of participants with seroresponse to demonstrate an acceptable immune response for IM administration of MMR vaccine
Time Frame: At Day 43
At Day 43

Collaborators and Investigators

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

Sponsor

GlaxoSmithKline

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)

April 17, 2025

Primary Completion (Estimated)

September 10, 2026

Study Completion (Estimated)

February 2, 2027

Study Registration Dates

First Submitted

February 25, 2025

First Submitted That Met QC Criteria

February 25, 2025

First Posted (Actual)

March 3, 2025

Study Record Updates

Last Update Posted (Actual)

May 29, 2026

Last Update Submitted That Met QC Criteria

May 27, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 223105
  • 2024-518840-18-00 (Other Identifier: EU CT Number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Study Sponsor will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk-studyregister.com/About_GSK_Patient_Level_Data_Sharing_Final_13July2023.pdf

IPD Sharing Time Frame

Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or asset(s) with development terminated across all indications.

IPD Sharing Access Criteria

Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months, but an extension may be granted, when justified, for up to 6 months.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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