Study of Rubella Immunity. Response to Vaccination of Subjects With Very Low, Equivocal or Undetectable Titers of Rubella Virus Antibodies

Inclusion Criteria: * Women over 18 * Rubella serology negative, ambiguous or weakly positive during a first prenatal consultation and for which the second determination of the immunity anti rubella is necessary after 18 weeks of pregnancy * Accepting the rubella vaccination after the childbirth; * Accepting a blood test, during a postnatal consultation, 6 in 8 weeks after vaccination, to verify their immunity towards the virus of the rubella. * Affiliated to a social security scheme * Having given a written consent Exclusion Criteria: * Rubella contracted since the first serology realized during the first prenatal consultation * Autoimmune pathologies * Intolerance / allergy known about a previous vaccination whatever it is * Immunosuppression (HIV, transplants) * Injection of multivalent immunoglobulins (except anti-D)