Although the studies below are dated and is specific to an MMR vaccine which has been withdrawn from the market in the UK, it is still an interesting read.
September 1992 – Vaccines containing Urabe strain of mumps withdrawn following demonstration of an increased risk of aseptic meningitis 15-35 days after vaccination.
September 1992 – May 1998 – following the withdrawal of the Urabe-containing mumps vaccines, the only MMR vaccines available was MMRII from Sanofi Pasteur, which contained the Jeryl Lynn mumps component. Subsequent reports from other countries showed that aseptic meningitis was associated with all mumps vaccine strains except the Jeryl Lynn strain.
May 1998 – replacement vaccine Priorix from GlaxoSmithKline introduced. No laboratory-confirmed mumps meningitis detected amongst children aged 12-23 months after administration of 1.6 million doses in England or Wales.
The study confirms that the risk of aseptic meningitis with Priorix vaccine, if it exists at all, is significantly lower than that with Urabe-containing mumps vaccines. The study allowed the exclusion of risk as rare as 1 in 437,000 for laboratory-confirmed mumps meningitis with non-Urabe-containing MMR vaccines.
Sources:
Risks of convulsion and aseptic Meningitis following Measles-Mumps-Rubella Vaccination in the United Kingdom. American Journal of Epidemiology – Vol. 165 No6 – DOI: 10.1093/aje/kwk045 – Advanced Access Publication January 4, 2007 – AM J Epidemiol 2007;704-709
