Before the vaccine was introduced in France, the number of annual mumps cases was estimated to be in the hundreds of thousands. Since then, the incidence—which was estimated in 1986 at 859 cases per 100,000 people—has fallen very rapidly. In 2020, it was estimated at 11 cases per 100,000 (95% CI: 8–14), or nearly 80 times lower.

Protection against mumps that diminishes over time

The median age of cases rose from 5 years in 1986 to 22.5 years in 2020. Vaccination status among cases differs significantly between the two periods. Currently, data from the Sentinelles network indicate very low viral circulation. However, several small outbreaks have occurred in recent years. These outbreaks have mainly been observed in communities of adolescents or young adults (schools, universities, sports teams).
Analysis of these episodes shows that a significant proportion of cases occurred in individuals vaccinated several years earlier with two doses of the MMR vaccine. Similar outbreaks have occurred in recent years in Western countries with high vaccination coverage (the U.S., Canada, the Netherlands, Israel, etc.). The data suggest that protection against mumps diminishes over time, even after two doses of vaccine.

An increase in two-dose vaccination coverage

The “two-dose” MMR vaccination coverage at 24 months has increased in recent years. It rose from 60.9% to 86.3% between 2010 and 2019.

European and global surveillance data

• https://ecdc.europa.eu/en/mumps

• https://www.who.int/immunization/diseases/mumps/en/