New York City has declared the measles outbreak affecting the Orthodox Jewish community in Williamsburg to be a public health emergency, Mayor Bill de Blasio said Tuesday, as reported by CNN.

Unvaccinated people living in select zip codes will be required to receive the measles, mumps and rubella vaccine, known as MMR, to curtail the outbreak and protect others, he said.

Under the mandatory vaccinations, members of the city’s Department of Health and Mental Hygiene will check the vaccination records of any individual who may have been in contact with infected patients. Those who have not received the MMR vaccine or do not have evidence of immunity may be given a violation and could be fined $1,000.

“Every hour, every day matters here. If people would just go and get vaccinated, there’s no cause for a fine,” said de Blasio. “It’s not our goal to issue violations. We want to simply solve the problem.”

New Yorkers should call 311 to access a list of facilities that can provide the measles vaccine at low or no cost, de Blasio said.

The public health emergency comes in response to 285 cases of measles reported in Brooklyn and Queens since the beginning of the outbreak in October. The same outbreak is responsible for 15 cases of measles in Orange County, New York, and 168 cases in Rockland County, New York. The outbreak began when, according to health officials, an unvaccinated child became infected with the illness while visiting Israel.