In the United States, reported cases of measles fell to a historic low in 1993, but a fourfold increase in 1994 underlines the need for continued vigilance. In Finland, indigenous measles, mumps, and rubella have been eliminated by a two-dose vaccination program, and substantial progress is being made in the Americas. Reported cases of mumps in the United States have declined by more than 99 percent to about 1,600 cases annually. Mumps primarily affects school-age children, but 35 percent of cases occur in adolescents and adults. A serologic survey of military recruits suggests that more than 15 percent of young adults in the United States are not protected against mumps.
Mumps vaccine is a live attenuated virus strain prepared from chick embryo cultures.
The vaccine is available alone, as mumps-rubella vaccine, or as MMR vaccine. MMR vaccine is the preparation of choice for the routine immunization of children at 15 months of age and at school entry and for older individuals who may be susceptible to measles and rubella as well as mumps. No adverse effects are associated with any of these vaccines in individuals who have been previously immunized against these diseases. Mumps vaccine is effective, inducing antibody production in more than 97 percent of recipients and providing clinical protection in 95 percent. Immunity is long lasting, and booster doses are not necessary.