A state of emergency has been issued in Rockland County, New York because of a measles outbreak. 

The measure went into effect at 12 a.m. Wednesday.

Anyone under the age of 18 without an MMR vaccine is banned from entering public places for 30 days. Those found in violation could face legal consequences.  County officials say the only exemption from vaccinations are people who cannot receive it for medical reasons.

The announcement comes nearly six months after the first measles case was reported in the county.  As of Tuesday, there are 153 confirmed cases, with 84 percent of the people infected under the age of 18.

The first cases were reported back in October with unvaccinated travelers visiting ultra-Orthodox and Hasidic communities in New Square and Monsey.                

Rockland County Executive Ed Day says parents will be held accountable if they are found to be in violation of the state of emergency. They could be subject to a $500 fine or even jail time.

News 12 asked the county executive how he would enforce that, but he said he does not anticipate that he’ll have to. "The focus of this effort is on the parents of these children. We are urging them once again with the authority of law, get your children vaccinated," said Day.

So far, nearly 17,000 vaccines have been administered through clinics in the county, and another one will be held this afternoon at the Rockland County Health Complex in Pomona at 1 p.m. There will be more clinics scheduled.

Officials say no cases of measles have been reported in Connecticut towns.