Measles is one of the most contagious of all diseases:
The measles virus stays in the air for up to two hours after an infected person leaves an area.
About nine in 10 people with close contact to a person with measles will get the disease if they are not vaccinated.
Measles is preventable when people get vaccinated. Keeping measles immunization levels high in our communities is critical to preventing measles outbreaks. Measles is still common in many other countries and may be brought into the United States by unvaccinated travelers.
Even though measles was declared eliminated in the United States in the year 2000, outbreaks still happen in communities with low immunization rates. That is why efforts to make sure people are fully vaccinated continue to this day.