Antibody concentrations are expressed as Geometric Mean Concentrations (GMCs) in milli International Units per milliliter (mIU/mL). Seropositivity was defined as subjects with anti-measles virus antibody concentration equal or greater than 150 mIU/mL.

ATP cohort for immunogenicity: included all eligible subjects with post-dose serology results available for at least one antigen of measles, mumps, or rubella, who complied with the protocol, who did not meet any elimination criteria and had no intercurrent medical conditions leading to elimination up to the Visit 2 (Day 42) blood sample.

Antibody concentrations are expressed as Geometric Mean Concentrations (GMCs) in EU/mL. Seropositivity was defined as subjects with anti-mumps virus antibody concentration equal or greater than 5 EU/mL

ATP cohort for immunogenicity: included all eligible subjects with post-dose serology results available for at least one antigen of measles, mumps, or rubella, who complied with the protocol, who did not meet any elimination criteria and had no intercurrent medical conditions leading to elimination up to the Visit 2 (Day 42) blood sample.

Antibody concentrations are expressed as Geometric Mean Concentrations (GMCs) in IU/mL. Seropositivity was defined as subjects with anti-rubella virus antibody concentration equal or greater than 4 IU/mL

ATP cohort for immunogenicity: included all eligible subjects with post-dose serology results available for at least one antigen of measles, mumps, or rubella, who complied with the protocol, who did not meet any elimination criteria and had no intercurrent medical conditions leading to elimination up to the Visit 2 (Day 42) blood sample.

Seroresponse was defined as:

Anti-measles virus antibody concentration equal to or above the threshold of 200 mIU/mL after administration of INV_MMR vaccine vs. COM_MMR at Day 42.

ATP cohort for immunogenicity: included all eligible subjects with post-dose serology results available for at least one antigen of measles, mumps, or rubella, who complied with the protocol, who did not meet any elimination criteria and had no intercurrent medical conditions leading to elimination up to the Visit 2 (Day 42) blood sample.

Seroresponse was defined as:

Anti-mumps virus antibody concentration equal to or above the threshold of 10 EU/mL after administration of INV_MMR vaccine vs. COM_MMR at Day 42.

ATP cohort for immunogenicity: included all eligible subjects with post-dose serology results available for at least one antigen of measles, mumps, or rubella, who complied with the protocol, who did not meet any elimination criteria and had no intercurrent medical conditions leading to elimination up to the Visit 2 (Day 42) blood sample.

Seroresponse was defined as:

Anti-rubella virus antibody concentration equal to or above the threshold of 10 IU/mL after administration of INV_MMR vaccine vs. COM_MMR at Day 42.

ATP cohort for immunogenicity: included all eligible subjects with post-dose serology results available for at least one antigen of measles, mumps, or rubella, who complied with the protocol, who did not meet any elimination criteria and had no intercurrent medical conditions leading to elimination up to the Visit 2 (Day 42) blood sample.

For subjects with seronegative status at pre-vaccination, a 4-fold rise in antibody concentration is defined as 4 times the cut-off level of the assay. Cut-off levels for anti-measles, anti-mumps and anti-rubella virus antibody concentrations are 150 mIU/mL, 5 EU/mL and 4 IU/mL.

ATP cohort for immunogenicity: included all eligible subjects with post-dose serology results available for at least one antigen of measles, mumps, or rubella, who complied with the protocol, who did not meet any elimination criteria and had no intercurrent medical conditions leading to elimination up to the Visit 2 (Day 42) blood sample.

Assessed solicited local symptoms were pain, redness and swelling. Any = Occurrence of any local symptom regardless of their intensity grade. Grade 3 Pain = Significant pain at rest. Prevented normal every day activities. Grade 3 redness = redness with surface diameter >50mm. Grade 3 swelling = swelling with surface diameter >50mm.

Total Vaccinated cohort included all vaccinated subjects with a documented vaccine administration.

Fever was assessed:Any fever (≥38°C) = occurrence of any fever regardless of its intensity grade or relationship to vaccination. Grade3 fever = fever >39.5°C. . Related = symptom assessed by the investigator as causally related to study vaccination.The preferred route for recording temperature in this study was oral.

Total Vaccinated cohort included all vaccinated subjects with a documented vaccine administration.

Assessed MMR specific symptoms were parotid/salivary gland swelling and any sign of meningism/seizure. Parotid/salivary gland swelling: Any = occurrence of any general symptoms regardless of their intensity grade or relationship to vaccination; Grade 3 Parotid/salivary gland swelling = Swelling accompanied with general symptoms. Meningism/seizure: Any= occurrence of any general symptoms regardless of their intensity grade or relationship to vaccination; Grade-3 meningism/seizure= Prevented normal, everyday activities (In adults/adolescents, such an AE could, for example, prevented attendance at work/school and could necessitated the administration of corrective therapy). Related symptom = symptom assessed by the investigator as causally related to study vaccination.

Total Vaccinated cohort included all vaccinated subjects with a documented vaccine administration.

Any untoward medical occurrence in a patient or clinical investigation child, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product

Total Vaccinated cohort included all vaccinated subjects.

Assessed any rash, Grade 3, Related, Localized rash, Generalized rash,measles/rubella-rash. Any= occurrence of any general symptom regardless of its intensity grade or relationship to vaccination. Grade3 rash/exanthema= Rash which prevented normal, everyday activities (In adults/adolescents, such an AE could, for example, prevented attendance at work/school and could necessitated the administration of corrective therapy). Grade 3 measles/rubella/varicella-like rash = Rash with more than150 lesions. Related = symptom assessed by the investigator as causally related to study vaccination.

Total Vaccinated cohort included all vaccinated subjects with a documented vaccine administration.

Assessed any, Grade-3, Related. Any= occurrence of any general symptom regardless of its intensity grade or relationship to vaccination; Grade3 joint pain (arthralgia/arthritis)= Pain which prevented normal, everyday activities (In adults/adolescents, such an AE could, for example, prevented attendance at work/school and could necessitated the administration of corrective therapy). Related = symptom assessed by the investigator as causally related to study vaccination.

Total Vaccinated cohort included all vaccinated subjects with a documented vaccine administration.

Occurrence of new onset chronic diseases (NOCDs)

Total Vaccinated cohort included all vaccinated subjects.

Occurrence of AEs prompting emergency room (ER) visits.

Total Vaccinated cohort included all vaccinated subjects.

A serious adverse event (SAE) is any untoward medical occurrence that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization or results in disability/incapacity.

Total Vaccinated cohort included all vaccinated subjects.