The order applies to anyone living, working or going to school in four ZIP codes in the neighborhood and requires all unvaccinated people at risk of exposure to the virus to get the vaccine, including children over six months old.
The outbreak has largely centred around ultra-Orthodox Jewish communities where immunisation rates are low.
Rockland County, located near New York City, has also declared a 30-day public health emergency over a measles outbreak there that has seen 168 people contract the disease, according to the CDC. "Our goal is to vaccinate people". Anyone who resists could be fined up to US$1000.
'You get phony, phony articles and studies, so yes, some people will fall for that, ' he said. Those who are uninsured will pay what they can afford, de Blasio said, and those who cannot afford the vaccination will receive it free.
To encourage immunization, the city has created the slogan, "Don't wait".
De Blasio, a Democrat, said officials were confident the order would withstand legal scrutiny.
"There's still a lot of speculation about vaccines out there and, of course, we try to dispel those myths all the time when we talk to families", Belmonte said. In other boroughs we've seen no cases.
"There is a very strong anti-vaccination propaganda movement in these communities, and they're very effective", said Blima Marcus, a nurse practitioner who lives in Brooklyn.
"I know that parents may be afraid of getting their child vaccinated, but as a pediatrician, I know that getting vaccinated is far safer than getting measles", said NYC Department of Health Commissioner Dr. Oxiris Barbot. Non-immune pregnant women are at particular risk, she said.
In the city alone, 285 cases have been confirmed - 246 of which have been in children. While there have been no confirmed deaths so far, 21 people have been hospitalized, with five admitted to intensive care, officials said. As of late last week, there had been at least 166 confirmed cases there. "As Passover is coming up, it's important that all New Yorkers get vaccinated especially if they plan to travel overseas to Europe or Israel".
Since the Health Department issued its mandatory exclusion order in December, numerous schools violating the city's emergency mandate played host to mini outbreaks of the extremely virulent disease, including one Williamsburg yeshiva that inspectors have connected to more than 40 cases since January.
Measles is a highly-contagious disease which is spread through the air and by person-to-person contact. "I urge everyone to get vaccinated". In 2018, there were 56 instances and there have been more than 225 cases already this year.
"We can not wait until someone dies for us to act".
Barbot said 8,000 people have been vaccinated since September 30.
Officials say the outbreak is spreading due to a small group of anti-vaxxers.
"To challenge the unsafe misinformation that is being spread by a group of anti-vaxxers, it's crucial that everyone around them be vaccinated to shield them from infection", Barbot said.
It said the vaccine was 97 per cent effective.
Health officials also expressed alarm at reports of parents in the city holding so-called "measles parties" where they intentionally expose their unvaccinated children to an infected child in the mistaken belief doing so is a safe means to create immunity.
On the other hand, Kentucky Governor Matt Bevin did recently claim that he exposed all nine of his children to a chickenpox-infected person. "We live in a different world now".
Earlier this week, the city ordered religious schools and day care programs serving that community to exclude unvaccinated students or risk being closed down.
Since October, the city has barred all kids who don't have the vaccine from attending school, including the private yeshivas.