Not even three months into 2025, the United States is approaching the number of measles cases it saw in all of last year: 222 and counting. A growing outbreak in Texas and New Mexico has claimed two lives, including one unvaccinated school-aged child.
In response, Secretary of Health and Human Services Robert F. Kennedy Jr. has praised the benefits of the measles, mumps, and rubella vaccine. But he has also touted the benefits of vitamin A, cod liver oil, and good overall nutrition as ways to stem the outbreak.
Here are four recent statements Kennedy made about measles and what infectious disease experts had to say about his handling of the crisis so far.
“The decision to vaccinate is a personal one.”
In an opinion piece published by Fox News, Kennedy wrote, “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.” He added that getting the vaccine is a personal choice.
Dr. Shira Doron, chief infection control officer for Tufts Medicine, said it was problematic for the country’s top public health official to not more aggressively endorse vaccination amid the current outbreak.
“Some vaccines could be a personal choice. For example, even the CDC leaves some leeway on certain vaccines,” said Doron, including one for Respiratory Syncytial Virus, which the Centers for Disease Control and Prevention recommends for everyone 75 and older but for only some adults ages 60 to 74. “But because [measles] is so contagious — it’s the most contagious virus that we know — you have to have a very high rate of vaccination in your community.”
Measles, best known for the signature red rash it causes, infects 9 out of every 10 unvaccinated people exposed to it. But it is also highly preventable. Two doses of the MMR vaccine — the first typically given when children are between the ages of 12 and 15 months and the second given between the ages of 4 and 6 years old — are 97 percent effective at preventing infection and provide lifelong immunity for most people.
Herd immunity for measles requires a 95 percent vaccination rate, yet in the Texas county where measles has been spreading, roughly 82 percent of the kindergarten population had received the measles vaccine. Nationally, US MMR coverage among kindergarteners has fallen below the 95 percent threshold and is decreasing, according to the CDC.
“Studies have found that vitamin A can dramatically reduce measles mortality.”
While it’s true that the World Health Organization recommends vitamin A for all children with measles, regardless of their country of residence, it is most frequently administered in low-income countries where malnutrition is common. In the United States — where fewer than 1 percent of the population is vitamin A deficient — there is no clinical proof that giving vitamin A to children reduces mortality or the illness’s severity, experts said.
“We’ve never done a trial in the US, so I can’t tell you for certain whether it’s beneficial or it’s not,” said Dr. Alfred Sommer, a professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health and a contributor to a 2020 report by the National Foundation for Infectious Diseases that urged further research into vitamin A treatment for measles in the United States.
The American Academy of Pediatrics notes that “many US experts concur with administering vitamin A to all children in the United States with measles, regardless of hospitalization status” and adds that children with more severe measles may have lower vitamin A concentrations.
However, vitamin A, unlike vaccination, cannot prevent measles. It’s also important for parents to consult doctors before giving children vitamin A, because it’s possible to overdose.
In a recent Fox News interview, Kennedy also claimed that children with measles in Texas were being given cod liver oil, which is naturally high in vitamin A.
Doron expressed confusion over Kennedy’s claims.
“You would not administer vitamin A that way,” she said. “It doesn’t have even close to what you would give if you were administering medical-grade vitamin A.”
Vitamin A — along with vitamin supplementation in general — has long been promoted by antivaccine activists as an alternative to vaccination for disease prevention, including by the antivaccine organization Children’s Health Defense, which Kennedy founded and formerly chaired.
“If you are healthy it’s almost impossible for you to be killed by an infectious disease in modern times.”
Kennedy made this claim in an interview with Fox News last week.
“Of course, a balanced diet is very important for health, but a nutrition-rich diet alone will not stop the most contagious disease in the world from infecting an unvaccinated child,” said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota last week on his podcast.
Doron echoed his comments.
“People should absolutely pay attention to their underlying health, including exercise, a healthy diet, stress management, smoking cessation, and optimizing chronic diseases like diabetes with medications,” she said. “Doing so will boost the immune system and reduce the risk of complications. However, even healthy people contract infectious diseases, have complications, and die.”
“By 1960 — before the vaccine’s introduction — improvements in sanitation and nutrition had eliminated 98 percent of measles deaths."
Doron criticized Kennedy’s historical framing of measles mortality. “It’s not percentages that we should care about, it’s absolute numbers,” she said. “We were seeing 400 to 500 deaths a year [prior to the introduction of vaccination], on top of that permanent disability in children due to measles.” Long-term effects of measles can include deafness, lung scarring, and sometimes fatal brain damage, Doron added.
“MMR vaccines and other vaccines are safe,“ said Dr. Vandana Madhavan, a pediatric infectious disease specialist at Mass General for Children. ”Unfortunately, that does not get the same amount of media attention as anti-vaccine misinformation, which has led to a greater rate of vaccine hesitancy,”
“If vaccine skepticism continues to spread, we’re going to see more outbreaks of diseases that had become rare in the US,” Madhavan added.
Nathan Metcalf can be reached at nathan.metcalf@globe.com. Follow him on Instagram @natpat_123.