As New York officials declared a public health emergency in parts of Brooklyn this week, establishing mandatory vaccinations in an effort to stop the city’s worst measles outbreak in almost 30 years, health advocates pointed to what they believe is a major source of vaccine misinformation in the affected neighborhoods.

The false messages that they say convinced hundreds of New Yorkers not to vaccinate their children weren’t spread in a Facebook group or on YouTube, but through a glossy magazine written by and for Orthodox Jewish parents. Copies of the magazine were shared in a way that seems old-fashioned in the age of misinformation — through family, friends and neighbors.

“The Vaccine Safety Handbook” looks legitimate but is filled with wild conspiracy theories and inaccurate data. Published by an anonymously led group called Parents Educating and Advocating for Children’s Health, or PEACH, the handbook disputes the well-established dangers of illnesses like measles and polio, challenges the effectiveness of vaccines in eradicating those illnesses, and likens the U.S. government's promotion of vaccines to the medical atrocities of Nazi Germany.

Inside its 40 pages, between cartoons mocking the medical establishment, PEACH’s magazine inaccurately suggests vaccines are made up of “toxins.” Without evidence, it claims that vaccines are the nation’s greatest threat to public health, linked to autism, ADHD, Sudden Infant Death Syndrome, miscarriage and other maladies.

A note from the handbook’s editor in chief explains why Parents Educating and Advocating for Children’s Health is an anonymous organization: “Please forgive us for our anonymity. It is not because we don’t believe in our cause. We do! It is because many of us have suffered abuse from fellow community members for questioning the medical authorities and advocating for children’s health.”

Yet according to New York State's Department of State and internet domain registration records, PEACH appears to be linked both to a decade-old misinformation hotline targeting the Orthodox community and to Enriched Parenting, a website that peddles new-age cures from a Jewish perspective alongside vaccine hoaxes.

Enriched Parenting’s website features retouched photos of children picking flowers in fields of lavender alongside articles that explain how concern over the measles outbreak is overblown. There are articles about how to beat back-to-school blues and treat urinary tract infections with herbs. There is also a forum where members trade sourdough recipes and alternative cancer treatments.

It’s not just trendy, it’s effective. Research shows combining vaccine misinformation with alternative medicine, homeopathy and diet content this way is one of the most pervasive and persuasive techniques used by anti-vaccination advocates to forward their agenda.

“When a piece of misinformation is linked to other beliefs, attitudes, values and behaviors that one already accepts, that misinformation becomes easier to understand and accept,” said Meghan Bridgid Moran, assistant professor at the Johns Hopkins Bloomberg School of Public Health. “And anti-vaccine websites can leverage this by associating misinformation about vaccines with alternative medicine or holistic healthcare.”

In 2017, members of Pittsburgh’s Orthodox Jewish community — which has largely embraced vaccinations — complained on Facebook that PEACH was targeting their neighborhoods by mailing out unsolicited copies of the handbook.

Since the start of the New York measles outbreak in October, 285 cases have been confirmed in the city, most of them unvaccinated or partially vaccinated children, resulting in 21 hospitalizations and five admissions to the intensive care unit. This outbreak, like others last year in New York and New Jersey, spread within Orthodox Jewish communities.

Blima Marcus, a nurse practitioner at Memorial Sloan Kettering Cancer Center and a member of the Orthodox Jewish Nurses Association, told the New York blog Gothamist that the magazine “was a piece of anti-vaccination propaganda” that was particularly effective in the Orthodox community in part due to “an almost genetic fear of whether what the government says is true.”

Dr. Oxiris Barbot, the city’s health commissioner, said Tuesday that the outbreak “is being fueled by a small group of anti-vaxxers in these neighborhoods. They have been spreading dangerous misinformation based on fake science.”

For a decade, through the Akeres Habayis Hotline, a recorded-message center for Orthodox Jewish women, PEACH has been spreading unfounded fears about vaccines in the Orthodox community and helping skeptical parents avoid them. Chany Silber, 41, has been moderating the conference calls since at least 2011, according to advertisements in Jewish magazines. In 2014, according to internet registration records, Silber bought the domain name PeachMoms.org — a website that never appears to have gotten past the “coming soon” phase.

Silber declined an interview when the website Gothamist rang her doorbell last month, but claimed that the Centers for Disease Control and Prevention “says a lot of fake things,” Gothamist reported. Silber did not respond to an email and text message requesting comment, and a woman coming out of Silber’s apartment Thursday ignored questions from an NBC News reporter.

There are several connections between PEACH and Enriched Parenting in online and public records. PEACH is registered as a nonprofit group with New York State’s Department of State. In those state records, PEACH lists Enriched Parenting, which describes itself as dedicated to “informing parents on how to promote their children's lifelong physical and emotional well-being,” as its website. In the past, “donate” links from the Enriched Parenting site, accessed by the Internet Archive’s “Wayback Machine,” led donors to a PEACH donation page. And the website enrichedparenting.org was registered in 2015 under the email address of founder and current president Rebecca Fleischmann, and lists as its organization’s name Parents Educating and Advocating for Children’s Health, according to historical internet domain records.

Calls and emails to Enriched Parenting and to Fleischmann were not returned. In a text from the phone number listed on Enriched Parenting’s website, a person who declined to be identified denied any association with the handbook.

A copy of the magazine, which lists Enriched Parenting among the first of eight “helpful websites,” currently appears on the Enriched Parenting website in a section labeled “assets.”

Asked about the numerous associations, another reply came via text.

“Enriched Parenting is a DBA of Parents Educating & Advocating for Children’s Health, Inc,” the text read. “Our organization is not affiliated with Peach magazine. We are an organization that supports religious, philosophical, and medical choice. We are not, nor ever have been ‘anti’ anything other than coercion and loss of civil liberties. We support informed decision making and right of choice for all parents. Our activities are geared toward education and health options on a wide variety of subjects not limited to vaccine information.”

From 2015 until the fall of 2018 — about the beginning of the current measles outbreak — Enriched Parenting’s website had a large section on its homepage dedicated to vaccines, according to historical internet records.

The entire vertical, which included dozens of articles and links to resources and research that pushed vaccine misinformation, was removed when the group rebranded and relaunched the website sometime after last August.

The rebrand came with a flashy new website, a revamped social media presence, and a less in-your-face method to anti-vaccination advocacy. Enriched Parenting seems to aspire to be a lifestyle brand.

Through Enriched Parenting, Fleischmann has hosted events featuring holistic health practitioners such as Long Island pediatrician Lawrence Palevsky, a star in the anti-vaccine world who has appeared in at least one anti-vaccine documentary, and Dr. Leonard Kundel, a dentist with disciplinary records in Connecticut and New York after being accused of improperly treating a patient in 2011, who practices a “whole body approach” to dentistry. Kundel is Fleischmann’s personal family dentist, according to her Instagram account, and keeps an “Enriched Parenting library” full of almost exclusively anti-vaccination books in his waiting room.

“I don’t associate Enriched Parenting with anti-vaccine only,” said Lena Podolsky, the manager of Kundel’s practice, who responded to a request for him to comment. “I’ve been to a couple of seminars and it's pretty cool. So I don’t think they’re controversial. They’re sort of really forward thinking.”

Other events included a “Spa Night for the Body, Mind & Soul,” which featured a homeopath who promotes herbal cures for depression and anxiety. Recently, the group has organized smaller group sessions for local chapters across six states with monthly themes like "Bloom Where You Are Planted."

Enriched Parenting’s Facebook page has over 1,900 followers. And its reach stretches beyond the Orthodox community, with its president and a partner contributing articles and posts in 162,000-member Stop Mandatory Vaccination, Facebook’s largest and most active private anti-vaccination group.

Moishe Kahan, 47, of Brooklyn, listed as a contributing editor in PEACH’s handbook, often posts to Enriched Parenting’s Facebook page. Along with helping administer Enriched Parenting’s page, Kahan also runs the group Jews and Vaccines, previously named Jewish Vaccine Skeptics. He did not immediately respond to emailed questions.

By Wednesday, few articles on vaccines remained on the Enriched Parenting site. An article from Binyamin Rothstein — an anti-vaccine advocate whose medical licenses were revoked in Maryland and New York in 2005 and 2012 respectively, for inappropriately treating patients with intravenous vitamins and hydrogen peroxide — suggested measles were not a threat to human life and the unvaccinated should just take Vitamin A. (Like other anti-vaccination advocates, Rothstein contends he does not oppose vaccinations, while spreading misinformation about their purported dangers.)

Rothstein, who currently leads PEACH conference calls on the Akeres Habayis Hotline, is licensed to practice in Pennsylvania, but he’s under probation by the medical board. The article was removed from the website Wednesday after an inquiry from NBC News.

Enriched Parenting’s YouTube channel and Instagram profile are still filled with anti-vaccination content.

The current mailing address listed on Enriched Parenting’s website is home to two school bus companies. Workers there told a reporter they had never heard of Enriched Parenting.