Anti-vaccine advocates have swayed parents in New York to refuse immunizations for their kids, sparking two of the largest measles outbreaks in the state’s recent history, according to local health officials.

As of April 10, at least 285 people in New York City — mainly in Brooklyn’s Williamsburg and Borough Park neighborhoods — had fallen ill. In nearby Rockland County, 168 people have caught the virus. The outbreaks have prompted health officials in both areas to declare states of emergency. In the city, officials ordered mandatory immunizations among unvaccinated people on Tuesday, threatening those who opt out with fines. Nearby Rockland took the unusual step of barring anyone under the age of 18 who hadn’t been vaccinated for measles from public places for 30 days in March. That order that was put on hold by a judge ten days later.

What’s notable here is that the affected communities are closely linked: Cases are occurring mostly among unvaccinated or under-vaccinated Orthodox Jews, particularly children. When asked why people are opting out of vaccines, the New York city health department said anti-vaccine propagandists are distributing misinformation in the community.

The fearmongerers include a group called PEACH — or Parents Educating and Advocating for Children’s Health — which appears to be targeting the Jewish community with misinformation about vaccine safety, citing rabbis as authorities, through a hotline and magazines. Brooklyn Orthodox Rabbi William Handler has also been proclaiming the well-debunked link between the measles-mumps-rubella (MMR) vaccine and autism. Parents who “placate the gods of vaccination” are engaging in “child sacrifice,” he told Vox.

Last fall, when the outbreak started, I talked to Orthodox Jews in New York about the outbreak and their vaccine concerns. And I learned that a minority distrust vaccines — for reasons that have nothing to do with religious doctrine.

Yet the fact that some Orthodox Jews live outside the mainstream, avoid technology, and hold rabbinic opinion in high esteem may leave them particularly vulnerable to anti-vaxxers.

”Being a religious Jew, you also get used to having a minority viewpoint,” said Alexander Rapaport, the CEO of the Masbia Soup Kitchen Network in Brooklyn, and a public face of the Hasidic community. “So if something is not mainstream, it doesn’t take you away from believing it.”

He also explained that some Orthodox Jews in Brooklyn go to school together, worship together, and live and travel together. This means a few unvaccinated people living in close proximity can be dangerous. But it also means making inroads with public health messages requires extra effort. “We see government invest in public health awareness a lot,” Rapaport said. “But it never trickles down to Yiddish speakers or people who don’t own TV sets.”

The story in New York is familiar: Other tight-knit communities — like the Somali-American community in Minnesota, the Amish in Ohio, and, more recently, Russian-language immigrants in Washington — have recently fallen victim to measles outbreaks as a result of vaccine refusal. This New York outbreak is a reminder of how vulnerable more insular groups can be to anti-vaxxers, and the unique challenges for public health advocates in countering their messages in these communities.

Measles was eliminated in the US in 2000 — but outbreaks linked to vaccine refusal have been popping up in insular communities

There’s one fact that makes the measles virus really scary: It’s one of the most infectious diseases known to man. A person with measles can cough in a room, leave, and — if you are unvaccinated — hours later, you could catch the virus from the droplets in the air that they left behind. No other virus can do that.

So if you’re not vaccinated, it’s extremely easy to catch measles. In an unimmunized population, one person with measles can infect 12 to 18 others. That’s way higher than other viruses like Ebola, HIV, or Sars.

By 2000, because of widespread vaccination, the virus was declared eliminated in the United States: Enough people were immunized that outbreaks were uncommon, and deaths from measles were scarcely heard of.

But in order for any vaccine to be effective, you need to have a certain percentage of people in a population immunized. That’s what’s known as “herd immunity,” and it means diseases can’t spread through populations very easily. With the MMR vaccine, 95 percent of people need to get the shot. So just a few people refusing vaccines can be dangerous.

Since 2000, we’ve seen outbreaks every year in populations with lower levels of vaccine uptake, totaling between 37 and 667 cases. The virus typically spreads when unvaccinated travelers visit places where measles is circulating widely and bring it back to other unvaccinated or under-vaccinated people in a close-knit community where some parents have been opting out of vaccines for their kids.

That’s what happened in two of the largest recent measles outbreaks in the US since the disease was eliminated. In 2014, measles spread among unvaccinated Amish people in Ohio after a missionary brought the virus back from the Philippines. And in 2017, a traveler sparked an outbreak in an unvaccinated Somali-American community in Minnesota.

In New York, the current outbreaks also originated with travelers who had recently visited Israel, where a massive measles epidemic is currently underway. The travelers returned to the US and spread it among unvaccinated or under-vaccinated New Yorkers.

But this is not an isolated incident. The Orthodox Jewish community has already faced numerous outbreaks of vaccine-preventable diseases in recent years, including whooping cough and mumps. As recently as 2013, another measles outbreak involving 58 cases became the largest in the city since 1992, nearly a decade before measles was eliminated, and cost the city $400,000 to contain.

The reason parents aren’t vaccinating in New York

Most of the people I spoke to for this story had no concerns about vaccine safety and happily vaccinate their families. The majority view is also that there’s no religious reason to avoid vaccines.

“From a religious point of view, people have to vaccinate,” Rabbi David Niederman, executive director and president of the United Jewish Organizations of Williamsburg, told me. Instead, people have a duty to protect their families and the most vulnerable in their communities. “Anything that causes harm — you have to do whatever you can to [avoid] that.”

Yet Rabbinic authority, and the argument about avoiding harm, is being used by anti-vaccine campaigners as a vehicle to spread misinformation.

Consider the story of Rachel,* an Orthodox Jew in Brooklyn. When her eldest child was 18 months old, she brought her baby to the doctor for the MMR vaccine. Soon after, the girl came down with a fever that climbed up to 106 and eventually had to be hospitalized.

“The doctor said there was no correlation with the vaccine,” the mother of seven, ranging in age 11 months to 15 years, recalls. But Rachel was skeptical. After that, she noticed her daughter was getting sick all the time. “Ear infections, viruses. I lived at the doctor’s office.” She thought vaccines might be the culprit.

So she read up on the shots in PEACH’s pamphlets, watched the anti-vaccine documentary Vaxxed, and talked to her neighbors in her Brooklyn Orthodox Jewish community.

“The rabbis that don’t think vaccines are the right way to go keep a low profile,” she said, “but I could name you a bunch of them.”

She read and heard about things that concerned her. The ingredients in vaccines didn’t seem safe or healthy, and she heard rumors of neighbors whose kids got autism right after their shots. (For the record, data on thousands of people over the past half-century have found vaccines are overwhelmingly safe and effective.)

So over the years, Rachel has vaccinated her kids “less and less.” Her two youngest aren’t immunized at all.

Nowadays, between bringing her children to school and changing diapers, the stay-at-home mom hosts a library in her home, where parents can borrow books about vaccines and discuss what they read. The library includes both pro- and anti-vaccine books. “People can read and decide for themselves.”

Her library is advertised in anti-vaccine materials that are being spread in Rachel’s community, and she’s now part of the minority who resists vaccines — one that’s helped spark two of the largest measles outbreaks in recent US history.

“It has been very difficult to dissuade parents”

Some of Rachel’s concerns are reflected in the Vaccine Safety Handbook, purportedly produced out of Brooklyn by the PEACH group. (The group declined to be interviewed for this story.) The book carries the slogan, “You can always vaccinate later. You can never unvaccinate,” pages of misinformation about vaccines, including the well-debunked link with autism, as well as advice from rabbis about the “Biblical commandment” to avoid putting one’s life or health in danger — including the danger of vaccines.

Another source of vaccine misinformation is Rabbi William Handler, who also holds the view that vaccines cause autism — and shares it with parents. “I explain to parents that public health authorities like [the Centers for Disease Control and Prevention] are not interested in individual children,” he said. The best way to avoid potential harm is to avoid getting immunized, he advises. “[Parents] don’t want to play Russian roulette with their children. It’s like child sacrifice.”

Though large-scale studies involving thousands of participants in several countries have failed to establish a link between the MMR vaccine and the mental developmental disorder, it’s the autism views that the New York City health department hears a lot of.

“Unfortunately the concern about whether there’s any linkage has really lingered and [because of] misinformation, and it has been very difficult to dissuade parents,” Jane Zucker, New York City’s assistant commissioner of the bureau of immunization, told Vox. “We hear they want to wait until the child is older so they know the child doesn’t have autism, then get the child vaccinated.”

The challenge of countering anti-vaccine rhetoric in isolated communities

New York State does not allow parents to refuse vaccines for philosophical reasons, though parents can get exemptions for health and religious reasons. Once children reach school, they have to present evidence that their kids have been vaccinated, unless they have been granted an exemption.

Zucker says vaccine levels in Jewish schools in New York City look average, although religious schools have more religious exemptions than non-religious schools. And before kids get to school, there’s a problem in Williamsburg: It has one of the lowest rates of vaccine coverage among young children, ages 19 to 35 months, in the city.

So it was no surprise to Zucker that the children currently affected by measles in this outbreak were all too young to be in school. According to the city health department, the Williamsburg and Borough Park measles cases involved only small children, ages ranging from seven months to 4 years old. (Rockland declined to provide details about the affected, citing privacy concerns.)

That means there’s a cohort of kids for which state vaccine laws aren’t applicable, and who are vulnerable to vaccine-preventable diseases.

“Once the kids get into school we know we have good vaccine uptake,” said Zucker. “It’s the delay, though, and that’s what’s linked to this outbreak.”

Reaching vaccine-hesitant parents isn’t easy, however. The public health department has sent notifications to schools and hospitals with large Orthodox Jewish populations, done outreach, and placed ads and distributed posters in Orthodox papers in both Yiddish and English.

Public health officials need to intervene before outbreaks start

But they need to try harder, community leaders said, and intervene before outbreaks start.

“We have a language barrier, a culture barrier,” said Rabbi Avi Greenstein, executive director of the Boro Park Jewish Community Council, in one of the affected areas, “and it only makes sense the health department should reach out to [our community].”

After outbreaks, posters about the importance of vaccines from the public health department will show up in community centers and neighborhood bodegas, said Alexander Rapaport, the Masbia Soup Kitchen CEO. But, “The posters from the city are reactionary,” he added, and not enough is being done to educate people ahead of outbreaks.

In a recent Facebook post, Rapaport also shared his view that the city vaccine mandate might backfire. “Instead of spending some real numbers on marketing and awareness they are trying coercion tactics. It will not work,” he wrote. “Spend some real money on a pro-vaccination message.”

Prior to the mandate, the outbreak led to a surge in MMR vaccine uptake among children in the city, according to data from New York City’s health department last fall.

So maybe the health emergency will be an opportunity to change people’s views. “It’s becoming increasingly clear if people take the position [not to vaccinate], they are an irresponsible person, an irresponsible parent,” Greenstein reiterated. “This is the challenge for the community.”

* We did not use Rachel’s real name because she was concerned about privacy and backlash about her views.