Breastfeeding after MMR shot: is it safe for baby?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Women: * Pregnant woman * Age ≥ 18 years * Planning to breastfeed her infant (mixed feeding is allowed) * Having a negative serology for rubella during pregnancy * Negative serology for measles based on the result from local laboratory * Affiliated to a social security regimen Infants: * Informed consent form signed by the person(s) holding parental authority. * Term newborn (≥36LMP) Exclusion Criteria: Women: * Woman having a multiple pregnancy * Woman planning to get pregnant in the month following the 2nd vaccination * Woman with known or suspected HIV infection * Woman with known or suspected immunodeficiency * Woman with family history of hereditary immune deficiency * Woman not mastering enough the reading / understanding of the French language to be able to consent to participate to the study * Woman incapable to follow the procedures of the study and to respect study visits for the whole period of the study. * Woman with contraindication for MMR vaccination: * Scarce hereditary problems of fructose intolerance * Woman with history of hypersensitivity to the active substances or to any of the excipients of the vaccine * Administration of human gammaglobulins in the past 3 to 11 months depending on the dose of human globulins administered (except for Rhophylac®) * Acute severe febrile illness within 7 days prior to injection * Woman under systemic corticosteroids (prednisone, or equivalent ≥10 mg/day) within the previous 15 days or planning to use corticosteroids (i.e. prednisone, or equivalent ≥10 mg/day) during the 15 days following vaccination * Woman under immunosuppressive therapy within the previous 3 months before vaccination or planning to use immunosuppressive therapy during the 15 days following vaccination Woman participating in any clinical trial with another investigational product 28 days prior to visit V0 or intent to participate in another clinical study with another investigational product at any time during the conduct of this study * Any other reason which, according to the investigator, may interfere with the evaluation of the study objectives * Woman with documented history of measles vaccination (1 or 2 doses) and/or history of documented measles Infants: * Blood draw is contraindicated or cannot be performed * Infant with family history of hereditary immune deficiency * Infant with suspected or confirmed immunodeficiency * Any other reason which, according to the investigator, may interfere with the evaluation of the study objectives