The city's health commissioner, Dr Oxiris Barbot, said that the majority of religious leaders in Brooklyn's large Orthodox communities support vaccination efforts, but that rates have remained low in some areas because of resistance from some groups that believe the inoculations are risky.
- New York City's Health Department is threatening to fine and possibly close several Yeshivas in Brooklyn that continue to allow unvaccinated children to attend class despite previous warnings prompted by a measles outbreak.
The order is signed to remain in effect until the next meeting of the New York City Board of Health on April 17 at which time "it may be continued or rescinded by the board".
The outbreak began when an unvaccinated child visited Israel, where thousands of people have been sick, contracted the disease, and came back to Brooklyn. He was joined by city health officials who decried what they called "misinformation" spread by opponents of vaccines.
In the modern era, measles is rarely fatal, but Center for Disease Control numbers showed 1 in 10,000 cases resulted in death before 1963.
The United States in 2000 declared measles eliminated from the country thanks to widespread vaccination, meaning it was no longer constantly present. Before then, between 3 million and 4 million people got measles every year, according to the CDC.
There have been 285 cases of measles since the outbreak began in the fall, mostly in the ultra-Orthodox Jewish community, and the number has more than doubled since February.
Under the order, any person living in the affected areas who has not been vaccinated must be immunised within 48 hours.
An outbreak in Rockland County outside New York City led officials to ban unvaccinated children from public places in mid-March.
Federal officials are also tracking outbreaks in New Jersey, California, Michigan and Washington state.
Many vaccine opponents believe medically baseless claims that inoculations can cause autism and other negative health effects.
"It's crucial for people to understand the measles vaccine works", de Blasio continued.
"As a pediatrician, I know the MMR vaccine is safe and effective", said New York City Health Commissioner Dr. Oxiris Barbot. She added that the city will help unprotected individuals secure affordable and accessible vaccination, and emphasized that vaccination is safe and effective.