Headlines

Clusters of Mumps Cases in 4 French Regions In France, data from the Sentinelles network and the limited number of reports of mumps clusters to the Regional Health Agencies (ARS) suggested very low circulation of the virus in recent years. Since late March 2013, several outbreaks have been reported to the ARS in four regions (Nord, Rhône-Alpes, Aquitaine, and Île-de-France) at universities among young adults. The current situation therefore indicates an increase in viral circulation. Initial data collected regarding the vaccination status of the cases show that the majority of them had received two doses of the combined measles-mumps-rubella (MMR) vaccine, in accordance with the vaccination schedule. This finding is not surprising. Indeed, several similar outbreaks have occurred in recent years (in the United States, Israel, and the Netherlands) during which the proportion of individuals who had received two doses of the vaccine ranged between 60% and 80%. This finding indicates a decline over time in the immunity conferred by MMR vaccination, with a greater decline for the mumps component than for the other two antigens. This is confirmed by data from the seroprevalence survey conducted in France in 2009–2010 (Sero-Inf Survey). Among individuals aged 20 to 24, 14% did not have antibodies at a level considered protective. [...]