[Reappearance of post-vaccination infection of measles, rubella and mumps. Should adolescents be revaccinated?].

Measles-mumps-rubella immunization has had a dramatic impact on the incidence of these diseases and their complications. However, a partial coverage, as seen in Belgium and France, only slows the spread of the wild virus, thus increasing the age at infection and the risk of complications. This is to be added to the fact that there are 5% primary vaccine failure (no antibody production) and 5% secondary vaccine failure (loss of antibodies over time). When introducing first immunization at 15 months of age it is thus very important to increase quickly the immunization coverage by immunization of all non-immune children entering school and by re-immunization of all teenagers.