NEW CITY, N.Y. (CBSNewYork) – Rockland County is taking the fight against the measles outbreak to summer camp, saying all campers and staff must be vaccinated.

The mandatory vaccination order includes day and overnight camps.

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Parents must provide documentation that their child has received two doses of the MMR vaccine.

Only medical exemptions, supported by a medical professional, will be accepted.

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There have been 255 measles cases confirmed in Rockland since the outbreak began last October.

The CDC said last week that the nation’s measles crisis has reached a level not seen in a generation, with nearly 1,000 cases reported this year.

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Most of those have been centered in the New York area and Orthodox Jewish communities.