Amid measles outbreak in Texas, RFK Jr. misleads on measles vaccine safety in Fox News interview

On 11 March 2025, Fox News aired an interview with Robert F. Kennedy Jr., the current secretary of the U.S. Department of Health and Human Services. During the interview, Kennedy discussed the current measles outbreak in Texas with host Sean Hannity.

According to the most recent measles update from Texas health authorities at the time of publication, there are 223 identified cases, 29 hospitalizations, and one confirmed death. Most cases have occurred in Gaines County, mainly in undervaccinated communities.

During the interview, Kennedy stated that “We will make sure anyone who wants a vaccine can get one” and acknowledged that the measles vaccine can stop the spread of the disease. But at the same time, he made several remarks undermining the vaccine, sometimes rehashing long-debunked misinformation. Kennedy, who for many years led the anti-vaccine organization Children’s Health Defense, has a record of making inaccurate and misleading claims about vaccine safety. We explain what’s wrong with his claims.

Kennedy draws false equivalence between measles risk and vaccine risk

Claim by Kennedy (Misleading): “There are adverse events from the vaccine, it does cause deaths every year, it causes all the illnesses that measles itself causes, encephalitis and blindness”

Kennedy provided no evidence to back up his claim. But his use of the term “adverse events” suggests the claim may be based on reports submitted to the U.S. Vaccine Adverse Event Reporting System (VAERS). Vaccine adverse events are untoward medical events that occur after vaccination. However, the mere fact that an adverse event occurred after vaccination isn’t proof positive that the vaccine caused the event. Causality depends on a number of factors, not just temporal association, as we explained in an earlier Insight article.

The VAERS website states that VAERS reports alone don’t establish causality:

“VAERS is not designed to determine if a vaccine caused a health problem, but is especially useful for detecting unusual or unexpected patterns of adverse event reporting that might indicate a possible safety problem with a vaccine. This way, VAERS can provide CDC and FDA with valuable information that additional work and evaluation is necessary to further assess a possible safety concern.”

In spite of this warning, VAERS reports are commonly misused by those spreading vaccine misinformation to suggest that vaccines are unsafe.

Another basis for Kennedy’s claim could be the measles vaccine package insert. Citing vaccine package inserts is another popular anti-vaccine tactic. For example, encephalitis and death are listed among the adverse reactions listed in the MMR vaccine package insert. Having said that, blindness isn’t, and it’s unclear what Kennedy based this particular claim on.

Like VAERS reports, the Adverse Reactions section on a vaccine package insert lists untoward medical events that occurred after vaccination, but doesn’t demonstrate causality. So it isn’t evidence that the vaccine caused the reaction.

As with any medical intervention, vaccines can cause side effects. The most common side effects from the MMR vaccine are fever, a rash, and soreness at the injection side. These side effects are expected as the immune system responds to the vaccine.

It’s true that the MMR vaccine can cause disease in a specific group: namely people who are immunocompromised, such as those with immunodeficiencies. This is because the MMR vaccine contains live virus. Unlike the wild measles virus, the vaccine strain is weakened, so it doesn’t cause illness in people with a normally-functioning immune system. But it can make people with weakened immune systems sick^[1-3]. Therefore, experts recommend that immunocompromised people avoid live vaccines like the MMR vaccine.

However, immunocompromised people are at even greater risk from measles than the general population^[4]. As they cannot receive the MMR vaccine, they rely on those around them to be vaccinated for protection (herd immunity). Because measles is highly contagious, a very high level of vaccine coverage is needed: 19 out of 20 people need to be vaccinated to achieve herd immunity.

Kennedy’s language implies that the risks of the MMR vaccine are similar to those of measles. But measles is more likely to cause chronic health problems than the vaccine, making his claim an example of false equivalency.

The Institute for Vaccine Safety at Johns Hopkins University states that on rare occasions, the MMR vaccine can cause febrile seizures in children, at a rate of 26.4 per 1,000 person-years. However, febrile seizures, while alarming to witness, are typically benign and don’t result in lasting effects.

Measles-containing vaccines, like the MMR vaccine, can also rarely cause immune thrombocytopenia. This is a condition in which platelets, cell fragments that aid blood clotting, fall to levels lower than normal. The Melbourne Vaccine Education Centre places the risk of vaccine-associated immune thrombocytopenia at roughly 1 in 25,000 doses.

Measles, on the other hand, causes complications at a greater rate. About 3 in 10 children who get measles develop complications, including ear infections that can cause hearing loss, eye damage that can cause blindness, and encephalitis that can cause neurological damage. About 1 in 1,000 will die even with treatment. And immune thrombocytopenia, mentioned earlier as a rare vaccine side effect, occurs more often with viral infection like measles. Measles also weakens the immune system by causing immune amnesia.

Like any medical intervention, vaccines can cause side effects. Most are benign and transient. In rare cases, some of these side effects can be serious. But measles infection is much more likely to cause serious health problems that lead to lifelong consequences. Getting vaccinated mitigates this risk by preventing measles and its associated complications.

When we weigh up the risks of the vaccine against that of the disease, it’s clear that the vaccine prevents more harm than it causes. Overall, the benefits of the MMR vaccine outweigh its risks.

Measles can cause permanent disability; death is not the only important negative outcome

Claim by Kennedy (Misleading): “The death […] from measles, historically it was between 1 and 1,200 and 1 and 10,000 and so it does not have a high infection fatality rate and the people who tended to die were people who had comorbidities and they were malnourished” 

According to the U.S. Centers for Disease Control and Prevention, before the vaccine was available, there were “about 500,000 reported cases and 500 deaths annually”. This would place the case fatality rate of measles at around 1 in 1,000, which is somewhat close to the lower end of Kennedy’s estimate.

While Kennedy characterized the measles fatality rate as one that’s not high, death isn’t the only negative outcome of measles infection. As we explained earlier, measles infection has the potential to cause permanent disability, like hearing loss and vision problems, in those who catch it. Neurological damage from measles can also result in intellectual disability.

So while it’s true that most who catch measles will survive, there’s no guarantee that they’ll return to full health.

It’s also true that healthy people with no nutritional deficiencies stand a better chance of fighting off an infection compared to people with preexisting medical conditions or malnourishment. Notably, vitamin A deficiency is associated with a greater risk of measles complications and death.

But the implication that most measles deaths occur in people who are already sick—and that healthy children aren’t at risk of death—is false. The American Academy of Pediatrics states that before the vaccine was available, most measles deaths occurred in previously healthy children. Indeed, the one confirmed measles death in the Texas measles outbreak so far was an unvaccinated child who was reported to be otherwise healthy.

REFERENCES

• 1 – Monafo et al. (1994) Disseminated measles infection after vaccination in a child with a congenital immunodeficiency. Journal of Pediatrics.
• 2 – Angel et al. (1998) Vaccine-associated measles pneumonitis in an adult with AIDS. Annals of Internal Medicine.
• 3 – Bitnun et al. (1999) Measles inclusion-body encephalitis caused by the vaccine strain of measles virus. Clinical Infectious Diseases.
• 4 – Permar et al. (2006) Immune Containment and Consequences of Measles Virus Infection in Healthy and Immunocompromised Individuals. Clinical and Vaccine Immunology.