Last week, leaders at the Centner Academy, a Miami private school, sent teachers an email with a stark warning: Skip the coronavirus vaccines or else you’re not welcome in the classroom.

“We cannot allow recently vaccinated people to be near our students until more information is known,” the school’s co-founder Leila Centner said in a letter first reported on by the New York Times.

Centner cited debunked misinformation to justify the policy, suggesting that “reports have surfaced recently of non-vaccinated people being negatively impacted by interacting with people who have been vaccinated,” despite medical consensus that the coronavirus vaccines effectively prevent serious infections and carry few risks.

The school’s decision alarmed public health experts and demonstrated the pervasive reach of misinformation about the vaccines, which have now been given to at least 141 million people in the United States. A dozen state attorneys general last month demanded that Facebook and Twitter do more to enforce policies against vaccine misinformation.

The Centner Academy is in Miami’s swanky Design District, known for art galleries, shopping and architecture. Tuition starts at $15,160 for part-time preschoolers and runs up to $29,850 for its middle school students.

Coronavirus vaccine makers have started clinical trials to test their vaccines on infants and teenagers, a crucial step toward controlling the pandemic. (Luis Velarde/The Washington Post)

In her letter to teachers last week and a second note sent to parents on Monday, the school’s co-founder alluded to misinformation about the vaccines’ impact on fertility and menstruation in women and girls and inaccurately suggested that vaccinated individuals “may be transmitting something” to unvaccinated people. Experts agree that vaccinated people cannot “shed” the vaccines and spread their effects to unvaccinated individuals.

None of the coronavirus vaccines approved for use in the United States have been linked to infertility, miscarriages or any other adverse impact on women’s reproductive health. The Centers for Disease Control and Prevention recommends pregnant women get a coronavirus vaccine, after observing “no safety concerns” among 35,000 women vaccinated during their third trimester. The CDC also said there were no vaccine-related safety concerns for the women’s babies.

The source of the unsupported concern in the letter is unclear, but the school has numerous public links with the anti-vaccination community.

David and Leila Centner identify themselves as “health freedom advocates,” and their school has posted guidance to help parents file for exemptions to state-required vaccinations. In late January, they invited Robert F. Kennedy Jr., a prominent anti-vaccine advocate, to speak at the school.

Two prominent anti-vaccine advocates also publicly endorsed the school’s decision on Monday and said they have relatives enrolled at the Centner Academy.

Christiane Northrup, an obstetrics and gynecology physician who promotes alternative medicine, posted on Facebook praising the school late Monday night. She posted a photo with Kelly Brogan, who co-runs an alternative health website and has a history of posting coronavirus misinformation on Instagram.

Both women were identified in a report last month by the Center for Countering Digital Hate and Anti-Vax Watch as one of 12 individuals, dubbed the “Disinformation Dozen,” responsible for spreading up to 65 percent of coronavirus misinformation online. That report led Democratic Sens. Amy Klobuchar (Minn.) and Ben Ray Luján (N.M.) to urge Facebook and Twitter to stop those prolific posters from “spreading content that can harm the health of Americans.”

After the report, Northrup defended her social media posts, arguing in a Facebook video that she would not “believe in unfounded conspiracies and become involved in something that would result in such defamation.” Her social media accounts remain active.

On Monday, Northrup again acknowledged the report while throwing her support behind the Centner Academy’s push to prevent teachers from getting the coronavirus vaccine.

“Spent some time with Kelly Brogan, MD, one of my soul sisters and a fellow warrior who also made the famous Disinformation Dozen list,” Northrup wrote on Monday. “We both have children (grandchildren in my case) who go to the Centner Academy, a miraculous school in Miami. We are keeping the vibration of joy and grounding as high as we possibly can!”

Northrup in recent weeks has posted on Instagram and Facebook claiming, without evidence, that the coronavirus vaccines may be interfering with women’s periods. In her posts, she also promoted anti-vaccine groups, including Millions Against Medical Mandates and Maine Stands Up, which have opposed mask mandates, social-distancing-related restrictions and the widespread use of the coronavirus vaccines.

The Centner Academy letter did not mention Northrup or any other sources, but it echoed many of the unsubstantiated claims the doctor has promoted on her social media accounts.

The letter sent to the Centner Academy staff last week gave employees two options to remain employed through the end of the school year: Teachers could either remain distanced from students if they had already received a coronavirus vaccine or delay vaccination and teach in person.

That letter also told teachers that, if they chose to receive the vaccination, they would only be allowed to return after summer break when clinical trials had been completed — and only if they had not already been replaced by the school in the meantime, the Times reported.