Study to Evaluate the Immunogenicity, Reatogenicity and Safety of Double Viral Vaccine (MR) for Measles and Rubella

Inclusion Criteria: * Both sex; * Good health (no significant medical history); * 11 months of age on the first dose of vaccine; * To be up-to-date with the national vaccination calendar; * Availability for follow-up throughout the study period; * Willing to provide name, address, telephone and other contact information in order to be contacted, whenever needed (example: in case of missing any scheduled visit, contact for confirmation of scheduling a visit, urgent safety notifications); * Willing to strictly follow the study protocol; * At least one legal guardian of the research participants must be able to understand and sign the informed consent form; * Legal guardians by the research participants who can understand the child's inability to participate in another clinical trial during the time they are participating in the study; * Legal guardian with intellectual capacity to fill out the signs of signs and symptoms at home. Exclusion Criteria: * Previous vaccination against measles and rubella; * Personal history of measles or rubella; * Personal history of anaphylactic shock, asthma, urticaria or other hypersensitivity reaction to previous vaccinations, or who are allergic or hypersensitive to vaccine components of the study; * Use of antiallergic injections with antigens within 14 days or less prior to vaccination; * Use of immunoglobulin in the last 12 months prior to vaccination; * Use of blood products in the last 12 months prior to vaccination; * Use of any type of vaccine less than 30 days prior to study vaccination; * Use of injectable vaccines less than 42 days after study vaccination; * Chronic use of any medications (except homeopathic medicines and trivial medication such as saline and vitamins); * Previous use of immunosuppressive or cytotoxic medication; * Use of systemic therapy with high doses of steroids; * Use of any type of medication in a clinical trial within 12 months prior to vaccination; * Personal history of clinically significant neurological, cardiovascular, respiratory, hepatic, renal, haematological, rheumatologic or autoimmune diseases; * Personal history of coagulopathies diagnosed by a physician or report of capillary fragility; * Personal history of seizures; * Personal history of an active (eg any cancer) or treated malignant disease that may recur during the study; * Personal history of sickle cell anemia; * Asplenia (absence of spleen or removal of the spleen); * HIV positive or history of any immunosuppressive disease; * Presence of any disorder which, in the opinion of the principal investigator, may interfere with the evaluation of the study objectives; * Legal guardian with limited capacity for adherence to the study, according to the researcher's evaluation; * Impossibility of blood collection for pre-vaccine evaluation.