Why vaccination rates are falling in the U.S.

Record measles cases and rising childhood vaccine exemptions in the U.S. have fueled concerns that Americans are increasingly turning against vaccines.

But the reality may be more complicated than that. 

The biggest challenge for public health officials trying to contain deadly diseases may not be widespread anti-vaccine sentiment or the influencers and political figures who spread it. Only a small share of Americans indicate they firmly believe common myths about the shots, according to a survey released in July by health policy research organization KFF. 

Many other Americans fall into a large, uncertain middle ground — neither firmly pro-vaccine nor staunchly opposed — where they have questions or anxieties about shots and may be susceptible to conflicting messages about their safety and effectiveness.

KFF presented adults with four common vaccine myths. Fewer than 1 in 10 respondents said each claim was definitely true. But at least half fell into a gray area, saying the claims were either “probably true” or “probably false.” 

“What’s more true is a lot of people are confused,” Drew Altman, KFF CEO and founding president, said in an interview. “They don’t know who to believe, they don’t know what to believe, and that means that a lot of America is stuck in the middle, unsure and they’re up for grabs.”

That uncertainty could pose a growing public health hazard as the Trump administration reshapes federal vaccine policy and health officials grapple with declining immunization rates for some shots. Vaccine misinformation has a larger megaphone than ever with Trump in the White House: Earlier this month, without evidence, he linked the measles-mumps-rubella vaccine to autism, as he called for splitting the routine childhood immunization into separate shots.

People who are confused about vaccines may become “paralyzed” and delay or avoid decisions such as whether to immunize their children, Altman said.

The majority of Americans still get themselves and their children vaccinated, but “even little dips in that coverage could lead to more of a highly contagious virus like measles circulating,” said Jess Steier, a public health scientist and founder and CEO of Unbiased Science, which specializes in making complex scientific concepts understandable.

Still, she emphasized that while people with questions about vaccines may be susceptible to misinformation, they can also be reached through clear, evidence-based information and conversations with trusted healthcare providers. 

“Uncertainty can resolve once people have time, information and access,” she added. 

Vaccine hesitancy is much more complicated than outright opposition to vaccines, Steier said. Social media and the current political environment only fuel more of the confusion, she added. 

People are often exposed to emotionally charged, alarming content online because social media algorithms tend to amplify it, Steier said. As a result, many people are encountering conflicting messages about vaccines and struggling to determine which sources are trustworthy. Rather than being firmly anti-vaccine, many are simply overwhelmed by competing information, she said. 

Some of that messaging comes from political leaders such as Trump and Health and Human Services Secretary Robert F. Kennedy Jr., which makes the challenge facing other public health officials tougher. Kennedy has frequently said that he is not “anti-vaccine,” but he has a well-documented history of spreading scientifically inaccurate information around vaccine safety and efficacy.

Based on years of reviewing comments, questions and survey responses from people engaging with Unbiased Science’s social media platforms, Steier developed a framework for understanding vaccine hesitancy. 

She identifies five broad groups: “Lost” people who are confused by conflicting information and don’t know whom to trust; “Anxious” people who fear side effects; “Naturalists” who prefer natural immunity and are skeptical of medical interventions; “Distrusters” who are broadly suspicious of institutions such as government, medicine and pharmaceutical companies; and “Shruggers,” who aren’t opposed to vaccines but don’t view them as a priority or necessary for themselves.

Steier noted that while those are major factors driving vaccine hesitancy, people likely won’t “cleanly fall into one of these buckets.” 

Dr. Lori Handy, an attending physician and associate director of the Vaccine Education Center at Children’s Hospital of Philadelphia, agrees. 

“What we actually find is that individuals don’t bucket as nicely as we want because the factors that play into either having questions or having hesitancy about vaccines are really complex and are coming together as this combination of social factors, religious factors, access factors and who’s on their Instagram feed,” she said in an interview. 

Some people’s beliefs about one vaccine may not even transfer over to another shot at times, Handy added. 

Andrew, a 19-year-old from Pennsylvania who asked that his last name be omitted for privacy, said his family is the primary reason why he has not yet received any vaccines. He said several factors shape his family’s skepticism about immunization: misinformation, distrust of the healthcare industry and the government, and their religious background. 

He said he grew skeptical of his family’s vaccine positions over time and eventually researched immunizations, which helped him “know the reality better” and decide to start getting vaccinated. He said he’s “fairly certain” he’ll get caught up on all the major vaccines over the next few months.

He said he still has a few concerns about vaccines, such as potential side effects, but noted that the bigger issue at hand is the conflict his decision could create within his family.

Many Americans are uncertain about vaccines at a time when the U.S. is seeing record cases of measles, potentially heightening the risk to public health. 

The U.S. has so far reported 2,566 confirmed measles cases and 38 new outbreaks across 47 jurisdictions this year, marking a 35-year high that surpasses 2025’s previous multidecade record, according to data released this month from the Centers for Disease Control and Prevention. More than 93% of the infected individuals are unvaccinated or have an unknown vaccination status, the agency said. 

At the same time, U.S. childhood vaccination rates have inched down to about 92% for kindergartners, while nonmedical exemptions reached a record high of 4.2% during the 2025-2026 school year, the CDC said this week. Those exemptions — the majority of which are for non-medical reasons — represent an estimated 155,000 children nationally.

This postpandemic decline in both figures leaves some communities vulnerable and could help fuel the resurgence of preventable illnesses such as measles.

“This is one of those really terrifying things about certain infectious diseases — they are just so spreadable in so many areas, and when you have a high population of unvaccinated individuals, they will inevitably get infected when they encounter that virus,” Steier said. 

Handy said hesitancy around the measles vaccine dates back to 2000 or even earlier. She cited a publication, which has since been retracted, that tried to link the measles-mumps-rubella, or MMR, vaccine to autism despite studies repeatedly proving that there is no relationship. 

Still, that unfounded claim has continued to make some parents question the MMR shot, Handy said. Over the last two to three years, political leaders have further added to that skepticism by questioning the measles vaccine and attempting to change recommendations around it. 

Trump this month signed an executive order that suggests splitting the MMR shot, falsely claiming that the combined version is “quite lethal” and tying the vaccine and other jabs to autism. That type of rhetoric “makes parents less and less likely to vaccinate their child because they are seeing individuals in a position of authority who do not endorse it,” Handy said. 

While the infectious disease and pediatric communities still strongly recommend the measles vaccine due to its safety record, some parents trust different authorities, she added. 

“All of a sudden, vaccine science has become a political issue or a partisan issue in a way that we’ve never seen before, and it is really, really challenging to be part of the American public and not know which message to trust because we are seeing different messages come out from the government, from our healthcare providers, from different health authorities, and people really have to then decide,” Handy said. 

Health experts said that addressing vaccine-hesitant people starts with listening rather than lecturing. 

“We’ve been a bit more paternalistic in the past, where we tell people things versus listening first and understanding why they might be hesitant or what questions they have,” Steier said. “A lot of this, in my opinion, centers on listening first, understanding what’s driving the hesitancy, not dismissing these things outright.”

Instead of dismissing social media as a source, providers should acknowledge that many people rely on platforms such as TikTok for health information and then help them compare that information with evidence from trusted medical sources, Handy added. 

The goal is to have an open conversation that addresses individual fears and helps people better evaluate the information they see, she said. 

Handy also argued that vaccines have become victims of their own success. 

Because diseases such as measles were largely eliminated for decades, many parents have never seen the illness firsthand and don’t view it as a serious threat. As a result, the perceived risk of the disease is lower than the perceived risk of the vaccine, she said. 

“We’re in a different period with a different risk profile that people need to understand for their child,” Handy said. “Let’s revisit this question that parents may have because times have changed, and we need to really keep their child safe.”