Health officials in New York are cautiously optimistic that they have a large measles outbreak under control after tackling the noxious anti-vaccine myths and unfounded fears that fueled the disease’s spread.

Since last fall, New York has tallied 177 confirmed cases of measles, the largest outbreak the state has seen in decades. It began with infected travelers, arriving from parts of Israel and Europe where the highly contagious disease was spreading. In New York, that spread has largely been confined to ultra-Orthodox Jewish communities.

As measles rippled through those insular religious communities, health officials ran into members who were wary of outsiders as well as those who harbor harmful myths and fears about vaccines. This included the completely false-yet-pernicious belief that the measles vaccine causes autism.

To quash the outbreak, health officials met with rabbis and pediatricians in the community, who in turned urged community members to be vigilant and, above all, get vaccinated, according to The New York Times.

“Good people, great parents were terrified,” Rabbi Yakov Horowitz, founder of Darchei Noam yeshiva in Monsey in Rockland County, told the Times. Despite the fears, he insisted parents vaccinate their children. “They felt that I was asking to give their children something that would harm them.”

Rabbi David Niederman, a community leader and executive director of the United Jewish Organizations of Williamsburg, explained how he persuaded members of his congregation. “We are telling people the health department is looking out for your health… They are the experts and you should take the vaccinations.”

Health officials also reported confronting “a small pocket of people who are anti-vaccine who have been peddling this information, fostering confusion and fear.”

With a lull in new cases, health officials are optimistic that the tactics worked. “I’m sort of holding my breath,” Dr. Jane Zucker, head of New York City’s health department’s Bureau of Immunization. “I think we have promising news, but I don’t want to be optimistic too soon.”