Measles vaccine.

Administration of measles vaccine has sharply reduced the occurrence of measles. However, "mini epidemics" occurring at increasing intervals through 1989 brought about the need for a routine two-dose schedule of measles vaccination. The prevention of preschool cases and school-based cases are two major goals of this new schedule. A two-dose schedule will address the latter goal, however, it will not affect the more difficult problem of measles among preschoolers, a group with lower immunization rates than school-age children. The use of Edmonston-Zagreb measles vaccine in developing countries offers the promise of reducing worldwide disease rates in young infants in the future. However, the major goal in the United States and other developed countries is to increase levels of measles immunity.