Hundreds of parents and vaccine skeptics have called on New York lawmakers not to narrow existing exemptions to the state childhood immunization rules.

The group stood in the rain outside the state Capitol Tuesday urging lawmakers to protect a state law that permits people not to vaccinate their children for religious reasons. They say that parents are best suited to make medical decisions for their children — even if the vaccines are recommended by public health experts.

Some lawmakers have proposed eliminating the religious exemption amid an ongoing measles outbreak. Most of the cases seen in New York are among unvaccinated people in Orthodox Jewish communities.

Measles was once common in the U.S. but gradually became rare after vaccination campaigns that started in the 1960s.