NEW SQUARE, N.Y. (CBSNewYork) — Officials in Rockland County confirmed on Wednesday a measles outbreak has gotten worse. So far, there have been 40 confirmed cases, and most of those affected are children.

Authorities warned the disease is more than just an uncomfortable rash. Complications can occur, that’s why they’re hoping the public takes the expanding outbreak seriously.

“We already have two children who have been hospitalized with measles, and one is in intensive care,” Health Commissioner Dr. Patricia Schnabel Ruppert said.

In addition to the 40 confirmed cases, nearly a dozen more are suspected.

Starting Monday, all students in New Square who have not received a measles vaccine will have to stay home from school. A similar policy is in place for the rest of the county at schools with a low vaccination rate.

Health officials say the new policy impacts more than a thousand students.

According to the state, students in kindergarten through 12th grade must have at least two doses of the measles vaccine, but there are some exceptions.

“I’ve met with rabbis and I’ve asked them directly if there’s a religious reason why people should not be vaccinated, and they said no,” Ruppert said.

The new police gives parents two options: either they vaccinate their child, or the student will have to stay home from school until the outbreak is over — which could be weeks or even months.

Officials say free vaccines will be made available at the community outreach center in Monsey.