New York City declared a public health emergency Tuesday over a measles outbreak and ordered mandatory vaccinations in one neighborhood for people who may have been exposed to the virus.
Mayor Bill de Blasio announced the unusual order amid what he said was a measles "crisis" in Brooklyn's Williamsburg section, where more than 250 people, mostly members of an ultra-Orthodox Jewish religious community, have gotten measles since September.
The order applies to anyone living, working or going to school in four ZIP codes in the neighborhood.
The declaration requires all unvaccinated people who may have been exposed to the virus to get the vaccine, including children over 6 months old.
People who ignore the order could be fined $1,000. The city said it would help everyone covered by the order get the vaccine if they can't get it quickly through their regular medical provider.
"If people will simply cooperate quickly, nobody will have to pay a fine," de Blasio said.
New York City's health commissioner is empowered by law to issue such orders in cases where they might be necessary to protect against a serious public health threat.
Earlier this week, the city ordered religious schools and day care programs serving that community to exclude unvaccinated students or risk being closed down.
Officials say 285 measles cases have been confirmed in New York City since the beginning of the outbreak, the largest in the city since 1991.
New York City accounted for about two-thirds of all U.S. measles cases reported last week.
Another Jewish religious community, north of the city but with close ties to Brooklyn, has also seen a surge, with at least 166 cases since October. Last week, a state judge blocked an attempt by Rockland County officials to halt the spread of measles by banning unvaccinated children from public places.
The Centers for Disease Control and Prevention recommends that all children get two doses of measles vaccine. It says the vaccine is 97% effective.