Measles outbreaks: what does it represent for the elimination strategy in the region of the Americas? A call for the action.

The US is experiencing a large multi-state measles outbreak that started in California in 2014. At this time, no source case for the outbreak has been identified. Measles was declared eliminated in the US in 2000, because at that time, there were high coverage rates with the two-dose schedule and these vaccines have been very immunogenic. Measles is still endemic in many parts of the world, and outbreaks can occur when unvaccinated groups are exposed to imported measles virus. The current multi-state outbreak underscores the ongoing risk of measles importation, the need for high measles vaccination coverage rates, and the importance of a prompt and appropriate public health response to individual cases and outbreaks. The US outbreak threatens measles control in the Americas. Strengthening immunization programs and keeping vaccination coverage rates above 95% with a two-dose schedule will be necessary for measles control strategies in the Americas.