A vial of measles, mumps and rubella vaccine and an information sheet is seen at Boston Children's Hospital in Boston. (Brian Snyder/Reuters)

JERUSALEM — Ultra-Orthodox Jews in Israel have been hit especially hard by the country’s year-long measles outbreak, which has spread to some ultra-Orthodox communities in the United States.

The reason, health officials say, has nothing to do with religion and everything to do with the ultra-Orthodox way of life, as well as public health services that don’t meet the needs of large families.

“Most rabbis encourage vaccination based on the Torah commandment to protect one’s life,” said Rabbi Yuval Cherlow, founder and head of the ethics department of the Tzohar Rabbinical Organization in Israel. “In Judaism, the majority has the right to dictate what takes place in the public space to ward off danger.”

Still, “there is no pope in Judaism, and no one can force you to vaccinate,” Cherlow said.

In 2018, Israel’s Health Ministry reported 4,000 cases of measles, compared with 30 the year before. In the United States this year, 387 cases have been reported through March, compared with 372 during all of 2018, according to the Centers for Disease Control and Prevention.

Vaccination rates among ultra-Orthodox Jews in both countries have risen in recent months, following calls by prominent rabbis for their community’s children to be vaccinated and even bans on unvaccinated individuals from schools and synagogues.

But new cases are being reported in some particularly insular ultra-Orthodox communities in Israel, New York and New Jersey, where rabbis believe more in the will of God than in the authority of health officials.

In late March, Ed Day, county executive of Rockland County, N.Y., declared a state of emergency intended to bar unvaccinated children and teenagers from public places. About 6,000 unvaccinated children, many of them ultra-Orthodox, attend schools in the county.

In 2018, three outbreaks in New York state, New York City and New Jersey took place mostly among unvaccinated people in Orthodox Jewish communities, associated with travelers who brought measles back from Israel, according to the Centers for Disease Control and Prevention.

Despite outbreak clusters, the “vast majority” of American Jews, like their Christian and Muslim counterparts, have been vaccinated, said Joshua Williams, an assistant professor of pediatrics at the University of Colorado who studies the role of clergy in the vaccination process.

Ultra-Orthodox Jews who refuse to vaccinate their children “tend to cite secular concerns about the safety of vaccines, the risk of autism and side effects, and not religious doctrine,” Williams said.

Rafi Goldmeier, a blogger who writes about Orthodox life, said few Jews refuse to be vaccinated on religious grounds “because being anti-vax has nothing to do with Judaism.”

If anything, Goldmeier said, “among the extreme haredim [ultra-Orthodox sects] it’s due to a lack of trust in the government. If they see something like vaccination promoted by the government, they may refuse to do it.”

Hagai Levine, head of the environment health track at the Hebrew University-Hadassah Braun School of Public Health and Community Medicine, said vaccination refusal in the Israeli ultra-Orthodox community is “very rare” and that about 96 percent of Israeli children are vaccinated.

That number rises to nearly 100 percent in Israel’s Christian and Arab Muslim communities, which generally follow the recommendations of their leaders.

When ultra-Orthodox parents do not vaccinate their children, it’s usually because health services aren’t tailored to their specific needs, Levine said.

“We know from research from past and current measles outbreaks that in families with many children, where the mother is out working and the father is studying Torah full time, it’s very difficult to get all the children immunized on time. They are not anti-vax,” he said.

In Israel, where the average family has three children, ultra-Orthodox families have seven children on average, though 10 or 12 is not uncommon. Half of all ultra-Orthodox Jews live below the poverty line because of the community’s high birthrate and the fact that Torah study for men is often valued over workplace participation.

While the first child or the first few children are vaccinated at the proper time, “the 10th child is not well vaccinated,” Levine noted.

Levine said Israel’s universal health-care system could do more to prevent measles. He would like to institute home visits for the purpose of vaccination or at the very least, extend the opening hours for clinics.

Prevention in the tightknit ultra-Orthodox community is vital, Levine said, because of its overcrowded conditions and the high percentage of babies too young to be vaccinated.

“Because measles is so contagious, a vaccination rate of 80 to 85 percent isn’t enough to contain it,” he said.

One young American Israeli mother who requested anonymity because she does not want to create discord in her family, said she was fearful when her son underwent a brit, or ritual circumcision in Israel, a few months ago.

“There’s been a big measles outbreak in Israel, and my husband is from a huge ultra-Orthodox family,” she said. “Some of his siblings don’t vaccinate their children, so when it came time to invite people to the brit, I didn’t want to invite the non-vaxxers.”

She said she decided to host the entire family to keep “shalom bayit” — peace in the home — but kept her baby away from relatives.

Levine emphasized that Israel’s measles outbreak is fueled by outbreaks in other countries such as Ukraine and in Europe.

“The problem didn’t start with us, but we weren’t protected enough, and now we have an outbreak,” he said. “Now it’s our obligation to increase our efforts and vaccinate more people.”