Measles in Saudi Arabia: from control to elimination.

This article describesthe tremendous efforts made in the field of measles immunization in Saudi Arabia in the past 20 years, from the control phase to the elimination phase. Mandatory measles vaccination with one-dose Schwartz vaccine was introduced in 1982 by a royal decree, a step aimed at increasing vaccine coverage. In 1991, a two-dose schedule was implemented using Edmonston-Zagreb measles vaccine, with a first dose at 6 months to protect children younger than 9 months and a second dose of MMR at 12 months of age to protect those who did not respond to the first dose. A marked reduction in the epidemic peak and a shift of infection to older age were noticed. But the same data showed that 50% of measles cases in the 1- to 4-year age group occurred in vaccinated children. In 1998, with the start of elimination phase, an MMR campaign was launched in two phases, targeting school children in 1998 (secondary schools) and in 2000 (primary and intermediate schools). Evaluation of the MMR campaign and surveillance data was reflected in the measles immunization policy by shifting the age of measles immunization to 12 months and to preschool using the two-dose MMR schedule.