NCT06855160

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

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

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 900 (estimated)
• Sponsor: GlaxoSmithKline · Industry
• Sex: All
• Age: 12 Months – 15 Months
• Healthy volunteers: Accepted

Summary

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.

Conditions

• Chickenpox

Interventions

Type	Name	Description
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.

Timeline

• Start date: 2025-04-17
• Primary completion: 2026-09-10
• Completion: 2027-02-02
• First posted: 2025-03-03
• Last updated: 2025-12-04

Locations

12 sites across 2 countries: United States, Belgium

Regulatory

• FDA-regulated drug study