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.
• 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.