A Study on the Safety of an Investigational Chickenpox Vaccine, When Given to Healthy Children, 12 to 15 Months of Age

May 27, 2026 updated by: GlaxoSmithKline

A Phase 3a, Observer-blind, Randomized, Controlled Study to Evaluate the Safety of an Investigational Varicella Vaccine Compared With Varivax, Administered as a First Dose to Healthy Children 12 to 15 Months of Age

The purpose of this study is to assess how well-tolerated GSK's investigational varicella vaccine (VNS Vaccine) is, in comparison to an already approved varicella vaccine (VV) known as Varivax. The study will be conducted on healthy children aged 12 to 15 months, and who have neither contracted varicella nor received a varicella vaccination.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

750

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

  • Bulgaria
      • Burgas, Bulgaria, 8008
        • Withdrawn
        • GSK Investigational Site
      • Gabrovo, Bulgaria, 5300
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Svetla Pashova-Mihova
      • Kyustendil, Bulgaria, 2500
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Iliana Gogeva
      • Plovdiv, Bulgaria, 4002
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Miroslava Bosheva
      • Rousse, Bulgaria, 7000
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Svetoslav Dachev
      • Sevlievo, Bulgaria, 5400
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Stanka Kalcheva
      • Yambol, Bulgaria, 8600
        • Withdrawn
        • GSK Investigational Site
  • Denmark
      • Aarhus N, Denmark, 8200
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Nina Breinholt Staerke
      • Copenhagen, Denmark, DK-2100
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Anja Poulsen
      • Hvidovre, Denmark, 2650
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Thomas Benfield
      • Odense C, Denmark, DK-5000
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Isik Johansen
  • Estonia
      • Tallinn, Estonia, 10617
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Kaia Kiiroja
      • Tallinn, Estonia, 10615
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Eve Kivistik
  • Hong Kong
      • Hong Kong, Hong Kong, 00852
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Wing Shan Queenie See
      • Shatin, Hong Kong
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Agnes Sze-Yin Leung
  • Lithuania
      • Kaunas, Lithuania, 47116
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Giedra Leviniene
      • Kaunas, Lithuania, LT-48259
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Alina Kucinskiene
  • Mexico
      • Durango, Mexico, 34000
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Juan Carlos Tinoco-Favila
      • Tlalpan, Mexico, 14340
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Guadalupe Maldonado-Colin
  • Poland
      • Bydgoszcz, Poland, 85-796
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Oleg Warszalewski
      • Trzebnica, Poland, 55-100
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Henryk Szymanski
        • Contact:
        • Contact:
      • Warsaw, Poland, 02-172
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Damian Okrucinski
  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85006
        • Withdrawn
        • GSK Investigational Site
      • Tucson, Arizona, United States, 85741
        • Withdrawn
        • GSK Investigational Site
    • California
      • Huntington Park, California, United States, 90057
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Jose Diaz
        • Contact:
        • Contact:
      • National City, California, United States, 91950
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Mohammed Bailony
      • West Covina, California, United States, 91790
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Holly Lim
        • Contact:
        • Contact:
    • Florida
      • Hialeah, Florida, United States, 33012
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Jorge Alsina
      • Miami, Florida, United States, 33142
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Giselle Deiros
    • Illinois
      • Chicago, Illinois, United States, 60621
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Ayoade Akere
    • Kansas
      • El Dorado, Kansas, United States, 67042
        • Withdrawn
        • GSK Investigational Site
    • Louisiana
      • Lafayette, Louisiana, United States, 70508
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Jibran Atwi
        • Contact:
        • Contact:
    • Minnesota
      • Mankato, Minnesota, United States, 56002
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Mary Kathryn Smentek
    • Nebraska
      • Lincoln, Nebraska, United States, 68516
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Luke Anschutz
        • Contact:
        • Contact:
    • Ohio
      • Cincinnati, Ohio, United States, 45245
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Christopher Peltier
    • Texas
      • Dallas, Texas, United States, 75230-2571
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Ronald Blair
        • Contact:
        • Contact:
      • Dallas, Texas, United States, 75235
        • Withdrawn
        • GSK Investigational Site
      • Houston, Texas, United States, 77065
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Kashif Ali
        • Contact:
        • Contact:
      • Richmond, Texas, United States, 77469
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Michael Bornstein
        • Contact:
        • Contact:
      • San Antonio, Texas, United States, 78244
        • Withdrawn
        • GSK Investigational Site
    • Utah
      • Roy, Utah, United States, 84067
        • Completed
        • GSK Investigational Site
      • Syracuse, Utah, United States, 84075
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Peter Silas
    • Virginia
      • Richmond, Virginia, United States, 23294
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • John Scott
        • Contact:
        • Contact:
      • Vienna, Virginia, United States, 22180
        • Withdrawn
        • GSK Investigational Site

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 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 study entry.

Exclusion Criteria:

  • History of any reaction or hypersensitivity likely to be exacerbated by any component of the study interventions.
  • Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
  • Hypersensitivity to latex.
  • Recurrent history of uncontrolled neurological disorders or seizures.
  • History of varicella disease.
  • Active untreated tuberculosis
  • Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study.
  • 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.
  • Planned administration of a vaccine in the period starting 30 days before the dose and ending 43 days after the dose of study interventions administration (Visit 2), with the exception of inactivated influenza vaccine which may be given at any time during the study and administered at a different location than the study interventions. Any other age-appropriate vaccine may be given starting at Visit 2 and anytime thereafter.

  • 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 hepatitis A virus.
  • Previous vaccination against varicella 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.
  • 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).
  • Child in care.
  • Any study personnel's immediate dependents, family, or household members.

  • 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 less than (<) 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: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: VNS Group
Participants receive 1 dose of a VNS vaccine, 1 dose of measles, mumps, and rubella (MMR) vaccine, 1 dose of hepatitis A (HAV) vaccine, and 1 dose of PCV (either PCV 13 or Vaxneuvance or PCV 20) on Day 1.
Biological: Investigational varicella vaccine
1 dose of investigational varicella vaccine administered subcutaneously.
Biological: Measles, mumps, and rubella vaccine
1 dose of measles, mumps, and rubella vaccine co-administered subcutaneously or intramuscularly.
Biological: Hepatitis A vaccine
1 dose of hepatitis A vaccine co-administered intramuscularly.
Biological: PCV (pneumococcal conjugate vaccine) 13
1 dose of 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
1 dose of 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: Vaxneuvance
1 dose of 15-valent pneumococcal conjugate (Vaxneuvance) 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.
Active Comparator: VV Group
Participants receive 1 dose of a marketed VV, 1 dose of MMR vaccine, 1 dose of HAV vaccine, and 1 dose of PCV (either PCV 13 or Vaxneuvance or PCV 20) on Day 1.
Biological: Measles, mumps, and rubella vaccine
1 dose of measles, mumps, and rubella vaccine co-administered subcutaneously or intramuscularly.
Biological: Hepatitis A vaccine
1 dose of hepatitis A vaccine co-administered intramuscularly.
Biological: PCV (pneumococcal conjugate vaccine) 13
1 dose of 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
1 dose of 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: Vaxneuvance
1 dose of 15-valent pneumococcal conjugate (Vaxneuvance) 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
1 dose of marketed varicella vaccine administered subcutaneously.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of participants reporting each solicited administration site events
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 event
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
Time Frame: Day 1 (post-dose) to Day 22
Fever is defined as temperature greater than or equal to (>=) 38.0°C (100.4°F) by any route (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
Time Frame: Day 1 (post-dose) to Day 43
Solicited administration site include injection site varicella-like rash.
Day 1 (post-dose) to Day 43
Percentage of participants reporting solicited systemic events
Time Frame: Day 1 (post-dose) to Day 43
Solicited systemic events includes varicella-like rash (non-injection site), and general rash (not varicella-like).
Day 1 (post-dose) to Day 43
Percentage of participants reporting unsolicited adverse events (AEs)
Time Frame: Day 1 (post-dose) to Day 43
An unsolicited AE is an AE that was either not included in the list of solicited events or could be included in the list of solicited events but with an onset outside the specified period of follow-up for solicited events.
Day 1 (post-dose) to Day 43
Percentage of participants reporting medically attended AEs (MAAE)
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 adverse events (SAEs)
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)

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)

November 26, 2024

Primary Completion (Estimated)

November 23, 2026

Study Completion (Estimated)

November 23, 2026

Study Registration Dates

First Submitted

November 15, 2024

First Submitted That Met QC Criteria

November 15, 2024

First Posted (Actual)

November 18, 2024

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

  • 213997
  • 2024-515868-31-00 (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

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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