Author: Suzanne Nuyen, TEGNA | Published: 2:20 PM EDT March 26, 2019 | Updated: 2:20 PM EDT March 26, 2019

Rockland County, New York will declare a state of emergency today in response to an ongoing measles outbreak, according to multiple media reports.

The state of emergency will go into place at midnight on Wednesday. Under the declaration, anyone who is unvaccinated and under the age of 18 will be barred from public spaces, according to the Westchester Journal News.

A press release from the county said that as of March 26, there have been 153 confirmed reported cases of measles. 15 percent of those cases were in children less than 1 year old. 82.1 percent of people affected had not had the MMR vaccine.

Measles is a highly contagious respiratory disease caused by a virus. It is one of the most contagious viruses on earth. According to Rockland County, 90 percent of unvaccinated people exposed to the virus become infected.

Symptoms of measles include high fever, cough, runny nose and red, watery eyes. White spots can appear inside the mouth and a rash made of flat red spots can also appear a few days after infection.

The virus is especially dangerous for babies and young children, pregnant women and those whose immune system is compromised. Severe cases of measles can cause pneumonia, swelling of the brain and death.

The first case of measles was reported in Rockland County at the end of September last year. The Rockland Health Department is offering free vaccines and advising individuals who may have been exposed to the virus to contact their doctor before going in for care. They stress that those who have been exposed should tell their doctors before coming in so that facilities can prepare to prevent exposure among patients and faculty.