NCT06855160 · GlaxoSmithKline
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
What this study is about
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.
View original scientific description
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.
Interventions
BIOLOGICAL
Candidate varicella vaccine
Investigational varicella vaccine administered intramuscularly.
BIOLOGICAL
Marketed varicella vaccine
Marketed varicella vaccine administered subcutaneously.
BIOLOGICAL
MMR vaccine
MMR vaccine administered subcutaneously or intramuscularly.
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
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.
Primary outcome measures
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.
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.
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.
GMC of Anti-measles antibodies
Time frame: At Day 43
GMC of Anti-mumps antibodies
Time frame: At Day 43
GMC of Anti-rubella antibodies
Time frame: At Day 43
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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
Where
- Tucson, Arizona
- Huntington Park, California
- Sherman Oaks, California
- Coral Gables, Florida
- Miami Lakes, Florida
- Tampa, Florida
- Idaho Falls, Idaho
- Dayton, Ohio
- Houston, Texas
- Lewisville, Texas
- Mansfield, Texas
- Pharr, Texas
And 1 more location — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 29, 2026 · Source of record for eligibility and locations