As of 30 September 2026, 14 confirmed and one probable mumps case had been reported at San Diego State University, up from five confirmed or probable cases on 18 September. The outbreak remained confined to a single football team and one associated case, disrupting the team’s activities for three consecutive weeks.
Nationwide, 157 mumps cases had been reported across 31 US jurisdictions as of 10 September 2026, including 25cases in California.
Ensure you are immune to mumps before traveling!
Swiss recommendations: All persons born after 1963 who have no documented protection against infection should be vaccinated twice with MMR vaccine. Due to the insufficient effectiveness of the Rubini vaccine strain (contained in the previously administered vaccine Triviraten®), persons who had received this vaccine strain should receive additional MMR doses (i.e. 1 or 2 MMR doses, target: a total of 2 mumps-effective vaccine doses).