(CNN) There have been 971 cases of measles reported in the United States this year, the US Centers for Disease Control and Prevention said Thursday.

This means 2019, which is not quite half over, now has the greatest number of cases in a single year in nearly three decades.

The number of cases in 1994 was 963, which was lower than in 1992 when there were 2,237 cases.

"Measles is preventable and the way to end this outbreak is to ensure that all children and adults who can get vaccinated, do get vaccinated. Again, I want to reassure parents that vaccines are safe, they do not cause autism. The greater danger is the disease that vaccination prevents," said CDC Director Dr. Robert Redfield.

Measles was eliminated in the United States in 2000, meaning it was no longer continuously transmitted in the country.

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