A county in New York State has invoked a ban prohibiting unvaccinated children from attending public spaces like schools, malls, and places of worship amid a state-wide measles outbreak.

Rockland County announced the ban on Tuesday, as there have been 153 confirmed cases of measles in the New York suburb, which is about 20 miles north of Manhattan.

“We will not sit idly by while children in our community are at risk,” Rockland County Executive Ed Day said in a statement. “This is a public health crisis, and it is time to sound the alarm.”

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A recent report by the Centers for Disease Control and Prevention (CDC) indicated that the anti-vax movement has played a vital role in the global resurgence of measles outbreaks.

“Measles is extremely transmissible. Anyone who is unvaccinated is at risk for measles and puts other unvaccinated people, both in and outside their community, at risk of contracting this dreaded disease,” CDC said in a statement to Global Citizen. “State law gives health departments authority to broadly implement control measures in response to outbreaks.”

The MMR vaccine protects against measles, mumps, and rubella.

Anti-vaxxers often believe that the MMR vaccination is linked to autism due to findings published findings in the Lancet by now-discredited former doctor Andrew Wakefield. There has never been anything to back up Wakefield’s findings and they were retracted. A new study was also just released that dispelled his findings yet again.

In 2017, more than 100,000 people died from the measles — most of which were children under the age of 5. Unsurprisingly, the Rockland County outbreak has primarily affected school-age children.

The ban came in to effect as of midnight Wednesday and will last for 30 days or until unvaccinated children receive the MMR shot.

While it may be considered slightly unorthodox to ban children from attending public areas, pro-vaccine experts could argue that this is a way to encourage health security — protecting both vaccinated and unvaccinated children alike.

The current outbreak in Rockland County began when an unvaccinated resident returned to the suburb with measles after visiting Israel. Other outbreaks, such as the one in British Columbia, Canada.

New York City’s Brooklyn and Queens boroughs have also reported at least 181 cases of measles since October.