NEW YORK (CBSNewYork) – Health officials in the Tri-State area are taking an unusual step to prevent a recent measles outbreak from spreading further.

At schools that have dealt with confirmed cases, students who haven’t received the measles vaccination are being ordered to stay home until at least early November.

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At least 17 people have tested positive for the airborne disease. Officials say there are 11 in confirmed cases in Rockland County and six others in Williamsburg, Brooklyn.

(Credit: CBS2)

The outbreak is centered in Hasidic communities, including one in New Square. Banners and fliers throughout the community are urging people to receive the vaccination.

Several children at yeshivas have contracted measles, and now the Rockland health commissioner has ordered unvaccinated kids to stay home. It’s an action allowed under a seldom-used provision of state law, which required Dr. Patricia Schnabel Ruppert to get permission from the state’s Department of Health to issue the order.

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The county won’t say how many schools, or how many children, are affected.

“I think with children at risk, every measure needs to be taken to keep our children safe,” said New Square resident Aaron Eisenberg.

The vast majority of people are immune from measles after receiving the so-called “MMR vaccine,” but the disease can be highly contagious for the unvaccinated. Classic symptoms include red rash, fever, runny nose, red eyes that become sensitive to light, and coughing.

A quarter of victims wind up in the hospital.

“There are patients who have measles who have serious complications, especially for the younger children,” Dr. Ruppert said.

The commissioner says her order is a serious measure meant to stem a serious outbreak.

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Investigators believe travelers brought the disease from Ukraine, where there’s currently a massive outbreak. From there, they brought it to Israel and eventually New York.