A Study on the Immune Response and Safety of a Combined Measles, Mumps, Rubella, Chickenpox Vaccine Compared to a Marketed Combined Vaccine, Given to Healthy Children 4 to 6 Years of Age

Inclusion Criteria

• Healthy participants as established by medical history and clinical examination before entering into the study.
• A male or female between, and including, 4 years and 6 years of age (i.e., from 4 year birthday until the day before the 7-year birthday) at the time of study intervention administration, and in accordance with local regulations.
• Participant who previously received a first dose of varicella-containing vaccine in the second year of life.
• Participant who previously received a single dose of measles-, mumps-, rubella-containing vaccine in the second year of life.
• Written informed consent obtained from the participants' parent(s)/legally acceptable representative(s) (LAR[s]) prior to performance of any study-specific procedure (participant informed assent will be obtained from participants in line with local rules and regulations).
• Participants' parent(s)/LAR(s), who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of electronic diaries [eDiaries], return for follow-up visits).

Exclusion Criteria

Medical Conditions

• History of any reaction or hypersensitivity likely to be exacerbated by any component of the study interventions including hypersensitivity to neomycin or gelatin.
• Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
• Hypersensitivity to latex.
• Major congenital defects, as assessed by the investigator.
• History of measles, mumps, rubella, or varicella disease.
• Recurrent history of or uncontrolled neurological disorders or seizures.
• Acute disease at the time of enrollment. Acute disease is defined as the presence of a moderate or severe illness with or without fever. Fever is defined as body temperature >=38.0 degrees Celsius (°C) (100.4 degrees Fahrenheit [°F)] by any age-appropriate route. All study interventions can be administered to participants with a minor illness such as diarrhea, mild upper respiratory infection without fever.
• Participant with history of coronavirus disease 2019 (COVID-19) who is still symptomatic.
• Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study.

Prior and Concomitant Therapy

• Use of any investigational or non-registered product (drug, vaccine, or medical device) other than the study interventions during the period beginning 30 days before the dose of study interventions (Day -29 to Day 1), or their planned use during the study period.
• Chronic administration (defined as more than 14 days in total) of immunosuppressants or other immune-modifying drugs during the period starting 90 days prior to the study intervention administration. For corticosteroids, this will mean prednisone equivalent >= 0.5 mg/kg/day or 20 mg/day whichever is the maximum dose for pediatric participants. Inhaled and topical steroids are allowed.
• Administration of immunoglobulins and/or any blood products or plasma derivatives during the period starting 180 days before the dose of study interventions or planned administration during the study period.
• Administration of long-acting immune-modifying drugs at any time during the study period (e.g., infliximab).
• Previous vaccination with a second dose of varicella-containing vaccine or measles-, mumps-, rubella-containing vaccine.
• Administration or planned administration of a vaccine not foreseen by the study protocol in the period starting 30 days before the dose and ending at 43 days after the dose of study interventions administration* (Visit 3), with the exception of:
• inactivated influenza (flu) vaccine which may be given at any time during the study and administered at a different location than the study interventions and,
• routinely recommended licensed childhood DTPa-containing vaccines which can preferably be co-administered a