Mother Jones illustration; Andrew Harnik/Getty
In the anti-vaccine world, few immunizations are as demonized as the measles, mumps, and rubella or MMR shot. For years, vaccine “skeptics” have falsely claimed that the MMR vaccine causes autism, or sickens children with the very diseases it protects them against. But this week, the anti-vax world faced a reckoning when Trump’s Secretary of Health and Human Services, Robert F. Kennedy Jr., one of the nation’s most prominent anti-vaccine activists, wrote an op-ed for Fox News calling for MMR vaccines to be “readily accessible for all those who want them” amid an ongoing and sometimes fatal measles outbreak in Texas and other states.
In the op-ed, published on March 2, Kennedy wrote that while the “decision to vaccinate is a personal one,” vaccines “not only protect individual children from measles but also contribute to community immunity, protecting those who are unable to be vaccinated due to medical reasons.” On Monday, Kennedy issued an official statement on the outbreak. “This situation has escalated rapidly, with the Texas Department of State Health Services (DSHS) reporting 146 confirmed cases since late January 2025, primarily in the South Plains region,” Kennedy wrote. “Tragically, this outbreak has claimed the life of a school-aged child, the first measles-related fatality in the United States in over a decade.”
To describe this as a pivot for Kennedy would be an understatement. Children’s Health Defense, the organization where he was chair and CEO until 2023 when he went on leave to begin his presidential campaign, has engaged in a decades-long fearmongering campaign about MMR and other vaccines. In 2019, Kennedy visited Samoa, where he met with two anti-vaccine activists and discussed vaccines with the country’s prime minister, later describing that conversation as having focused a “limited amount” on vaccines. Following his visit, vaccination rates dropped and a massive measles outbreak ensued; 83 people died, most of them children. (Kennedy has repeatedly denied that his visit was primarily about vaccines or could have increased anti-vaccine sentiment, claiming during his Congressional hearings that his primary purpose for being there was to promote a “medical informatics” system.)
Kennedy also wrote a series of op-eds for CHD accusing Merck, which manufactures the MMR vaccine, of “chicanery” and suggesting that the mumps portion of the vaccine is somehow both ineffective and causes infertility in young men. (The NIH, meanwhile, says no studies have been conducted to determine whether the MMR vaccine is linked to infertility in men. But mumps in adulthood or childhood certainly is, although that, too, is relatively rare.)
CHD didn’t respond to a request for comment from Mother Jones or mention Kennedy’s remarks in any of their Monday posts, newsletters, or broadcasts. On the organization’s morning TV show on Monday, British anti-vaccine activist Polly Tommey interviewed a self-styled vaccine expert who warned of the dangers of MMR, including claiming that the cases in Texas were likely caused by the vaccine shedding—which is to say, they believed that vaccinated people were transmitting measles to others and driving the outbreak. But public health experts overwhelmingly agree that vaccine shedding is not causing the outbreak; post-MMR vaccine shedding, while possible, does not transmit measles. Moreover, even if it somehow could, the strain that’s been identified in the outbreak is a wild-type virus, not the live attenuated virus found in vaccines. Nonetheless, blaming shedding for measles outbreaks has long been a common anti-vaccine talking point.
“You have to piece it together because they won’t tell you the full story. They don’t inform us of the facts.”
“You have to piece it together because they won’t tell you the full story,” CHD’s chosen expert declared. “They don’t inform us of the facts.”
During his confirmation hearings, Kennedy repeatedly insisted, despite strenuously and publicly advocating against virtually every vaccine on the schedule since 2005, that he is not “anti-vaccine.” Senator Bill Cassidy of Louisiana, a physician and a key vote for Kennedy, ultimately voted to confirm him, after hesitating due to Kennedy’s anti-vaccine stance. Cassidy ultimately said that Kennedy had assured him the two men would have, in his words, “an unprecedently [sic] close collaborative working relationship if he is confirmed.”
Kennedy’s longtime allies and fellow travelers in the anti-vaccine movement were overjoyed by his confirmation. But they greeted his new MMR statements with a mixture of outrage, silence, and unusually cautious statements, seemingly waiting to hear more before denouncing Kennedy.
One of the major architects of the MAHA movement has yet to say anything at all. Film producer, Kennedy’s former campaign manager, and longtime fixture in the anti-vaccine world, Del Bigtree, is now the CEO of MAHA Action, a group made up of former team Kennedy staffers explicitly dedicated to furthering Kennedy’s MAHA agenda. Bigtree didn’t respond to requests for comment from Mother Jones about Kennedy’s remarks. He previously tried to reassure the faithful that Kennedy would remember his friends and principles when ensconced in the halls of power. “For all the doubters,” he tweeted in December with a link to a story about how, if confirmed, Kennedy would “investigate” the link between vaccines and autism. (Vaccines do not cause autism and such a purported link has been debunked many times over.)
Steve Kirsch, a Silicon Valley entrepreneur-turned-ardent anti-vaccine activist, also appeared to be reserving judgment on Kennedy’s statement. In the past, Kirsch has frequently repeated the debunked claim that the MMR shot causes autism. Recently, Kirsch has emerged as a major supporter of Kennedy and claimed he started a Super PAC to support his 2024 presidential run. Yet on X this week, Kirsch stopped short of criticizing Kennedy’s about-face on the MMR vaccine. He posted the editorial, and when a pro-vaccine account called The Real Truther asked him if he agreed, Kirsch responded, “I’m waiting to hear the backstory.”
Larry Cook, leader of the anti-vaccine group Medical Freedom Patriots, also didn’t quite come out against the statement. Shortly after Kennedy’s op-ed went up, Cook posted, “I read the measles and MMR vaccine statement by RFK Jr. Though unfortunate that the vaccine is being recommended, what also was mentioned is that it should be a parent’s choice (end vax mandates) and that nutrients and raising healthy children is also an option.” (Kennedy’s op-ed read, in part, “Good nutrition remains a best defense against most chronic and infectious illnesses. Vitamins A, C, and D, and foods rich in vitamins B12, C, and E should be part of a balanced diet.”)
Nicole Shanahan is a wealthy tech mogul and was Kennedy’s former running mate. Shanahan has claimed in the past that routine vaccinations caused her child’s autism and recently offered grants to “qualified researchers” to summarize the evidence between vaccines and a variety of health conditions. She also hasn’t weighed in.
Yet others have not been so restrained. Candace Owens, a rightwing political commentator and producer of a series of movies about the supposed dangers of vaccines, was one of the more vocal in her outrage, posting to her 6.7 million followers on X, “I’m thinking I might need to release the MMR episode of my Shot in Dark series for free so parents understand this is not a safe vaccine at all.” Responding to a comment on that post, she wrote, “RFK Jr. is friends with [Jewish author and influencer] Rabbi Shmuley. That’s all you really need to know.” (In the wake of the October 7 Hamas attack, Owens has repeatedly advanced antisemitic conspiracy theories.)
Another far-right influencer, live streamer Stew Peters, has also spoken out against Kennedy’s op-ed and used the opportunity to advance antisemitic claims. “RFK, Jr. is going to bring in the next death shot, healthy people will be dropping dead, Trump will ignore the mass die-off, tout the bioweapon as a ‘great accomplishment’, and MAGA will praise him,” Peters posted on Monday to his 789,000 followers on X. Later, he reposted a tweet that said “We were played by Trump, by Kennedy, by all the Jews in his cabinet,” adding the comment “It’s going to be ugly when MAGA figures it out.” In 2022, Peters rose to prominence by producing a movie called “Died Suddenly” that promoted the disproven claim that Covid vaccines were killing people.
“Has Sec. Kennedy already been captured by the vaccine industry? Or is there something else afoot here?”
Mike Adams, who goes by the name “the Health Ranger,” and who runs the wildly conspiratorial and reliably anti-vaccine website Natural News, was more alarmed. “Admittedly, this is VERY bad for the credibility of the MAHA movement,” he posted. “If MAHA = vaccines, then count me out.” Mary Talley Bowden, a doctor who advocated for disproven Covid treatments during the pandemic later reposted that tweet to her 526,000 followers. In his daily newsletter, Adams wrote, “Has Sec. Kennedy already been captured by the vaccine industry? Or is there something else afoot here?”
Yet others seemed to hope against hope that somehow, Kennedy would reveal that making pro-vaccine statements was part of the anti-vaccine plan all along. On Twitter/X, at least one MAHA fan tried to suggest that Kennedy was acting strategically.
“There are so many things in the article that have never been discussed on a national wide scale and people are missing it,” wrote one self-styled researcher with a modest audience who makes TikTok videos about politics. “I thought this was a great way to plant a seed for people who see vaccines as their religion. We can’t just tell these people ‘you are done with your vaccines.’ Imagine telling a Christian that God isn’t real. That’s what we are dealing with right now.”
