Aseptic meningitis following mumps vaccine. A retrospective survey by the French Regional Pharmacovigilance centres and by Pasteur-Mérieux Sérums & Vaccins.

Since 1989 many case series and observational studies of aseptic meningitis (AM) associated with the use of live attenuated mumps vaccines containing the Urabe AM9 strain have been reported worldwide. The aim of this retrospective reported AM in France following mumps vaccination with monovalent or multivalent vaccines containing the Urabe strain. Fifty-four cases of AM were reported to the Regional Pharmacovigilance centres or to the manufacturer from the time each vaccine was launched up until June 1992. Twenty cases were temporally associated with the administration of a monovalent mumps vaccine and 34 with a trivalent measles, mumps and rubella vaccine (MMR). A mumps virus was isolated in four cases in the cerebrospinal fluid and an Urabe-like strain was characterized twice by polymerase chain reaction (PCR). A probable mumps origin was assumed in 17 other cases where the patients presented with other clinical or biological signs of mumps infection. The clinical outcome of AM, known in 87% of the population, was always favourable. The global incidence of mumps vaccine-associated AM was 0.82/100,000 doses, which is significantly lower than the incidence in the unvaccinated population. Even considering that the actual incidence of AM is much higher when assessed by active surveillance studies, the risk/benefit ratio of mumps vaccine remains in favour of vaccination.