U.S. vaccine hesitancy rises as measles cases hit 35-year high and childhood immunization rates slip

Record measles cases and a slight drop in childhood immunization rates have highlighted growing uncertainty about vaccines among U.S. adults. A July survey by health-policy research group KFF found that fewer than one-in-ten respondents considered common vaccine myths to be definitely true, but about half were unsure, answering that the statements were "probably true" or "probably false."

"What's more true is a lot of people are confused," KFF CEO Drew Altman said. "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."

The Centers for Disease Control and Prevention reported 2,566 confirmed measles cases and 38 outbreaks across 47 jurisdictions this year, the highest in 35 years. More than 93% of those cases involved individuals who were unvaccinated or whose vaccination status was unknown. At the same time, CDC data showed kindergarten vaccination coverage slipping to about 92%, while non-medical exemptions rose to a record 4.2%, representing roughly 155,000 children.

Public health experts warned that even modest declines in coverage could allow highly contagious diseases like measles to spread more widely. Jess Steier, founder and CEO of Unbiased Science, said small drops in vaccination rates could increase the circulation of such viruses.

"Uncertainty can resolve once people have time, information and access," Steier added.

Researchers identified five broad categories of vaccine-hesitant individuals – "Lost," "Anxious," "Naturalists," "Distrusters," and "Shruggers" – but noted that people rarely fit neatly into a single group. Dr. Lori Handy of the Children's Hospital of Philadelphia emphasized that hesitancy stems from a mix of social, religious, access-related and informational factors, and that attitudes toward one vaccine do not always translate to others.

Political rhetoric has amplified confusion. President Trump recently claimed, without evidence, that the measles-mumps-rubella (MMR) vaccine is linked to autism and advocated splitting the combined shot. Health officials said such statements undermine confidence in vaccines.

Experts recommend that healthcare providers begin conversations by listening rather than lecturing, acknowledging the role of social-media platforms in shaping perceptions, and offering clear, evidence-based information.

"We need to revisit this question that parents may have because times have changed, and we need to really keep their child safe," Handy said.