CDC Vaccine Advisors Share Anti-Vax Content Days After Official Meeting

Members of the Advisory Committee on Immunization Practices have been promoting misinformation on X for days.

This post has been updated from its original email version.

Several of the members of the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices appointed last month by Health and Human Services Secretary Robert Kennedy Jr. have been posting anti-vax content on social media in the days since the panel met.

The anti-vax Kennedy fired the original 17 ACIP members ahead of the committee’s two-day meeting last month and replaced them with seven of his allies. On Tuesday, five days after the body met, one of those allies, committee chair Martin Kulldorff, took to the right-wing social media platform X to attack the nation’s largest professional association of pediatricians, the American Academy of Pediatrics.

Kulldorff, a biostatistician popular on the political right for his advocacy against COVID-19 mitigation measures, blasted the medical association over its continued support of thimerosal as a preservative in vaccines, accusing it of being “pro-mercury.”

“Mercury in vaccines creates distrust in vaccines, but the American Academy of Pediatrics is attacking CDC's ACIP after we no longer recommend mercury containing vaccines,” he wrote. “Astonishing that pro-mercury in kids is their battle cry!! @AmerAcadPeds.”

On Thursday, the newly-minted contrarian ACIP voted to recommend only seasonal flu vaccines free of the organomercury compound, which is used as a preservative in some vaccines. Thimerosal has long been a target of Kennedy’s despite having been largely removed from inoculations for decades—and despite scientific evidence indicating that its use as a vaccine preservative poses no risk to humans. Kulldorff moved into the world of anti-vaccine dark money after losing his job at Harvard Medical School over his refusal to get vaccinated against the disease.

AAP was highly critical of Kennedy’s reshaping of ACIP, noting that “More than 98% of families in this country choose to vaccinate their young children…now, vaccine policy is being shaped by the small, extreme minority that doesn’t.” The medical association boycotted last week’s meetings and its official X account posted a fact-check about thimerosal, decrying how “False information and faulty ‘science’” about the compound “are frequently used to mislead parents in an attempt to scare them out of vaccinating their children.”

In another post, it torched the advisory committee, writing, “This week's ACIP meeting was full of the same intentionally misleading fearmongering that causes vaccine hesitancy.”

“Children and families deserve better — public health information grounded in science,” the post read.

On Friday, the president of AAP put out a joint statement in STAT News with the presidents of other major medical associations, including American Academy of Family Physicians, American College of Physicians, American College of Obstetricians and Gynecologists, and the Infectious Diseases Society of America. Defying ACIP, the statement declared, “Our organizations will strongly continue recommending vaccines.”

Paul Offit, a pediatrician and renowned vaccine authority, told Important Context that “as head of the ACIP, Dr. Kulldorff should be aware of the differences between ethylmercury, which is harmless and the level contained in vaccines, and methylmercury, which has a much longer half-life and can be toxic at high quantities.”

“All mercury isn't the same,” Offit said. “The AAP's support of thimerosal as a harmless preservative in vaccines since the 1930s is because it virtually eliminated the cases of cellulitis, abscesses, and sepsis occasionally encountered with the inadvertent contamination of multi-dose vials.”

Kulldorff isn’t the only member of Kennedy’s reimagined ACIP to post anti-vaccine content since the panel met last week. Retsef Levi, a professor of operations management at the Massachusetts Institute of Technology who spent last week’s meeting promoting anti-vax narratives and was one of two votes against recommending a new RSV vaccine for children, shared Kulldorff’s mercury post as well another casting doubt on the safety of mRNA COVID vaccines for pregnant people.

Over the weekend, anti-vax physician and ACIP member Robert Malone posted a meme on X suggesting that immunizations were unnecessary. The meme featured an image of a smiling Amish man with the caption, in all capital letters:

“REMEMBER THE PLAGUE THAT WIPED OUT THE AMISH BECAUSE THEY DON’T VACCINATE THEIR CHILDREN? YEAH. ME NEITHER.”

Malone has made a career out of casting doubt on vaccines—specifically the COVID mRNA shots, which he has claimed cause a form of AIDS. Malone is a longtime ally of Kennedy and has been involved with several anti-vax groups. Those include The Unity Project, which sponsored the January 2022 Defeat the Mandates rally Kennedy spoke at, as well as his own Malone Institute, and the Independent Medical Alliance, an ivermectin-focused, anti-vaccine dark money group. He also spoke at the 2024 annual gala of the Brownstone Institute, which Kulldorff previously worked at.

Malone’s post went viral. As of this writing, it had received 105,000 “likes” and 19,000 retweets. However, it left out critical context.

Contrary to the meme’s implication that Amish children are fine without vaccines, most Amish have some level of vaccination, according to an Associated Press fact-check. There are also significant costs to low vaccine uptake in Amish communities—namely higher prevalence of vaccine-preventable diseases. A 2017 study, for example, found that Amish children were hospitalized with such diseases at significantly higher rates than other children outside of their communities. With the COVID-19 pandemic, the Amish were hit hard as well.

In its post on Malone’s meme, the Vaxopedia Substack compiled a list of notable outbreaks of vaccine-preventable diseases in Amish communities.

“As usual, Malone is wrong and spreading lies,” virologist Angela Rasmussen told Important Context. “Communities of any faith or culture that don’t vaccinate have been subject to explosive outbreaks of vaccine preventable diseases, particularly measles. I remember measles outbreaks that have disabled and killed children, including the current one raging in Mennonite communities in Texas that have claimed 2 young kids’ lives.”

Rasmussen, who is on the scientific advisory board of the Accountability Journalism Institute, which Important Context is part of, added, “These memes may seem innocuous but they kill children.”

Offit, meanwhile, recalled the 1979 polio outbreak, which hit three states and paralyzed 13 unvaccinated children in Amish communities.