In defending his record on measles, Health and Human Services Secretary Robert F. Kennedy Jr. twice said during a recent Senate hearing, “We promote” the measles vaccine. While it’s true that the Centers for Disease Control and Prevention continues to recommend the shot, Kennedy has rarely made an unequivocal endorsement of it, even as the nation has seen an alarming rise in measles cases.
Over a series of seven congressional hearings in April, Kennedy, who previously led a nonprofit that has spread vaccine misinformation, was quizzed about his views on the measles, mumps and rubella, or MMR, vaccine and his response to the many large outbreaks of measles over the last year and a half.
Experts blame the outbreaks on a decline in the vaccination rate, particularly in some areas of the country where vaccine coverage is especially low, which allows introductions of the disease to spread and grow. The U.S. eliminated the disease in 2000, meaning there hadn’t been continuous transmission of measles for more than a year within U.S. borders. With few exceptions, the U.S. has seen no more than a few hundred cases annually for many years. But since January 2025, there have been more than 4,200 cases and the first measles deaths since 2015.
When asked by a senator on April 22 what he was doing to reduce the number of measles cases and improve the MMR vaccination rate, Kennedy responded, “Improve the MMR. We promote the MMR. We have advised every child to get the MMR. That’s what we do.”
In the same hearing, Democratic Sen. Michael Bennet of Colorado similarly asked, “Are you taking the position, as your CDC director has taken, that the measles vaccine is vital to keeping American children healthy in this country? Are you taking that position today? That has not been your position.”
“That’s my position. I — we promote the measles vaccine,” Kennedy said. “The measles vaccine prevents measles in 97% of the people who take it. I’ve always said that. That’s what the science says.”
Kennedy had often noted the MMR vaccine’s effectiveness. But prior to last month, we could not find a single instance in which Kennedy offered vigorous, unqualified support for the vaccine, without including or later adding inaccurate or misleading information that might cause someone to rethink vaccination.
We reviewed his statements, focusing on the last year and a half, to put his claim in context. In the interactive timeline below, we identify Kennedy’s most significant remarks with respect to measles or the MMR vaccine.
For example, in an April 2025 X post that was widely covered by the press and angered some of his anti-vaccine supporters, Kennedy accurately stated that the MMR vaccine is the “most effective way to prevent the spread of measles.”
Later the same day, however, Kennedy posted again, writing that two local doctors “have treated and healed some 300 measles-stricken Mennonite children.” He cited two drugs that don’t have evidence to support them as a treatment for the disease.
Measles is a highly contagious viral illness that has no cure or specific therapies. While vaccination or immunoglobulin shortly after exposure can be effective, once someone is sick, physicians can only treat symptoms.
In much of his messaging, Kennedy was willing to say the vaccine works. But he also emphasized parental choice and spoke of vaccine safety concerns.
“We should have informed choice, and — but if people don’t want it, they shouldn’t be — the government shouldn’t force them to do it,” Kennedy said of vaccination in a March 11, 2025, interview with Fox News’ Sean Hannity, a little more than a month into a measles outbreak in West Texas. “There are adverse events from the vaccine. It does cause deaths every year. It causes — it causes all the illnesses that measles itself causes, encephalitis and blindness, etc. And so, people ought to be able to make that choice for themselves. And — and what we need to do is give them the best information, encourage them to vaccinate. The vaccine does stop the spread of the disease.”
The MMR vaccine is a very safe vaccine, and there isn’t evidence it causes deaths “every year.” While serious side effects can occur, they are rare. Because the vaccine contains a live but weakened virus, it can in extremely rare cases lead to a measles infection that can be severe or fatal in someone who is severely immunocompromised. For this reason, the vaccine is not supposed to be given to anyone who has a serious immunodeficiency. The Infectious Diseases Society of America notes on its website that there have been “no deaths shown to be related to the MMR vaccine in healthy people.”
Even when Kennedy has said that he recommends the vaccine — usually only when asked directly or pressed to do so — he limited the endorsement to certain groups or undercut it by offering other inaccurate information that could discourage vaccination.
In his first non-Fox network TV interview as secretary, Kennedy did say when asked that it was his position and the federal government’s position that “people should get the measles vaccine.”
“But,” he added, “the government should not be mandating those.” He went on to misleadingly say that the risks of vaccines are unknown because they are not adequately safety tested. (It is up to individual states to determine the vaccinations required to attend school; while all states as of 2025 require the MMR vaccine, it is not mandated at the federal level.)
Earlier in the interview, Kennedy baselessly claimed that the two children who died of measles in Texas actually died of other things (the state health authorities have said both deaths were caused by measles). He also wrongly implied that measles outbreaks were occurring “because the vaccine wanes very quickly.”
In each of these appearances, even if Kennedy did briefly say that the vaccine was being recommended, the overall takeaway for viewers may not have been to go out and get the vaccine.
Dr. David Gorski, a professor of surgery and oncology at the Wayne State University School of Medicine who blogs about vaccine misinformation and has been following Kennedy for more than a decade, told us that he had observed a nuanced shift in Kennedy’s language since becoming health secretary.
Kennedy has “toned down” his rhetoric, “but without really changing the overall message,” he said. “RFK Jr.’s and CDC’s messaging has basically been, ‘You can take the MMR if you want to and it’ll prevent measles, but measles isn’t so bad.’”
Kennedy, as far as we can tell, did not say the MMR vaccine was safe until his congressional testimony on April 16, when Rep. Madeleine Dean, a Democrat of Pennsylvania, asked him — yes or no — if the MMR vaccine is “safe and effective.” He said, “Yes.” But even then, he qualified the statement, adding, “It’s safe for most people.”
Other HHS officials have made stronger endorsements of the MMR vaccine.
“There is no cure for measles, which is why prevention is so critical,” Dr. Jay Bhattacharya, National Institutes of Health director and then-acting CDC director, said in a March 2 video posted to X. “The MMR vaccine remains the most reliable and effective way to prevent it. Two doses are 97% effective at providing lifelong protection against measles and its complications. Vaccination protects not only individuals but entire communities.”
Dr. Mehmet Oz, who heads the Centers for Medicare & Medicaid Services, told CNN on Feb. 8, “Take the vaccine, please. We have a solution for our problem.”
We reached out to HHS to ask for comment and also to identify positive remarks Kennedy has made about the MMR or measles vaccine. We didn’t get a response. Previously, the agency has told other news outlets that HHS leadership “has consistently said that the MMR vaccine is the best way to prevent the spread of measles and protect public health.”
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