New York City officials have declared a public health emergency in areas affected by a measles outbreak, with mandatory vaccinations now being ordered.
The outbreak has impacted people living in the ultra-Orthodox Jewish community in places such as Williamsburg in Brooklyn.
285 cases of measles have been confirmed since the beginning of the outbreak in October.
Most of the cases - 246 - have affected children under 18.
While no deaths have been linked to the outbreak, there have been 21 hospitalisations and five admissions to intensive care.
Authorities now say unvaccinated individuals living in affected areas will be required to receive the measles-mumps-rubella (MMR) vaccine.
Vaccination records of people who may have been in contact with infected patients will be checked, and anyone who hasn't received the vaccine could be fined $1,000.
Mandatory vaccinations
Mayor Bill de Blasio said: “There’s no question that vaccines are safe, effective and life-saving.
“I urge everyone, especially those in affected areas, to get their MMR vaccines to protect their children, families and communities.”
Health Commissioner Dr Oxiris Barbot, meanwhile, said the outbreak is being fueled by a 'small group of anti-vaxxers'.
She said: "They have been spreading dangerous misinformation based on fake science.
“As a pediatrician, I know the MMR vaccine is safe and effective."
Last month, one New York county banned children who haven't been vaccinated against measles from public places as a result of the outbreak.
Earlier this year, the UN warned that measles cases worldwide almost doubled in only a year.
According to the World Health Organisation (WHO), by mid-January this year they'd seen just under 230,000 reported cases of measles for 2018 around the world.
That compares to 115,000 cases from 2017 reported at the same time last year.
