A Study on the Immune Response and Safety of the Second Dose of an Investigational Chickenpox Vaccine When Given to Healthy Children 3 Months After a First Dose at 12 to 15 Months of Age

Inclusion Criteria: * Participant's parent(s)/Legally acceptable representative (LAR)(s), who, in the opinion of the investigator, can and will comply with the requirements of the protocol * 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 the first 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. * Hypersensitivity to latex. * Major congenital defects, as assessed by the investigator. * Recurrent history of uncontrolled neurological disorders or seizures. * History of varicella disease. * Active untreated tuberculosis. * Any other clinical …