Measles Cases Hit Highest Level Since 1991, Cato Expert Responds

“The CDC reported today that there were more measles outbreaks during the first five months of this year than in all of 2025—the highest number of cases since 1991. This news comes as the share of US counties where 95 percent or more of kindergartners have received the measles vaccine—the threshold needed to confer herd immunity—has dropped from 50 percent to 28 percent.”

“Secretary of Health and Human Services Robert F. Kennedy, Jr. has offered lukewarm support for the measles vaccine and has continued to question whether it causes autism—despite numerous large studies over the past several decades that have failed to find evidence of a link. He has also changed the language on the CDC website regarding “Autism and Vaccines” in a way that may reinforce concerns among vaccine-hesitant parents. Moreover, as my Cato colleague Adam Omary and I have written, autism’s high heritability makes a true epidemic unlikely, while broader diagnostic criteria and financial incentives have likely contributed to a surge in autism therapy spending.”

“No matter who occupies the White House, concentrating scientific authority in a federal bureaucracy invites politics to displace evidence. The CDC should return to its original mission of supporting state and local public health agencies as independent researchers, professional societies, and the broader scientific community evaluate the evidence and build scientific consensus.”