The Americas: paving the road toward global measles eradication.

BACKGROUND: The Region of the Americas set a goal of interrupting endemic measles virus transmission by the end of 2000. This decision was primarily based on rapid decreases in measles disease burden in pioneering countries that implemented Pan American Health Organization-recommended vaccination and surveillance strategies. Review of these strategies may inform measles elimination efforts in other regions.
METHODS: Results from the implementation of the measles elimination strategy in the Americas were compiled and analyzed over a 30-year period, which was divided into 4 phases: the early years of the Expanded Program on Immunization (1980-1986); the start-up phase for elimination (1987-1994); the elimination phase (1995-2002); and the postelimination phase (2003-2010). Factors that contributed to elimination and the challenges confronted during the postelimination phase are discussed.
RESULTS: An analysis of vaccination strategies over time highlights the transition from monovalent measles vaccine to the incorporation of measles-mumps-rubella vaccine administered in the routine program. Regional vaccination coverage increased during the period 1987-2010, sustained at ≥90% since 1998. Measles elimination efforts led to the implementation of 157 national vaccination campaigns, vaccinating a total of 440 million persons. Endemic measles virus transmission was interrupted in 2002. After elimination, measles importations and associated outbreaks occurred. Measles incidence has remained at <1 case per 1 million population since 2002.
CONCLUSIONS: The success of measles elimination strategies in the Americas suggests that global measles eradication is attainable.