Mumps incidence in Israel--impact of MMR vaccine.

BACKGROUND: Measles-mumps-rubella (MMR) vaccine replaced measles vaccine in the routine childhood vaccination schedule in Israel in December 1988, primarily to eliminate congenital rubella syndrome. In this observational study, we report on changes in mumps incidence in Israel from the time of the introduction of MMR vaccine until the end of 1991. METHODS: The report is based upon passive surveillance of mumps incidence, which has been notifiable in Israel since 1977. RESULTS: In the three years since the introduction of MMR vaccine, reported mumps incidence has fallen to less than 10% of the pre-vaccine period. CONCLUSIONS: Although this report is based on a relatively short period of observation, it can be tentatively concluded that MMR has led to a reduction in mumps incidence in Israel. It would be imprudent, however, to predict that mumps outbreaks will not occur in the future, and further observation of morbidity data will be needed to determine the magnitude and durability of the observed trend.