Measles Vaccination Rates Are Plummeting Across the U.S.

Childhood vaccination charges in opposition to measles, mumps, and rubella have been declining in a lot of the U.S. because the begin of the COVID-19 pandemic, a brand new research has discovered.

The research, which was published in JAMA on June 2, analyzed measles, mumps, and rubella (MMR) vaccination charges by county the place information have been obtainable. Researchers at Johns Hopkins College collected county-level information on MMR vaccination charges for kindergarteners from every state’s well being division web site for the college years earlier than the pandemic (2017-2018) and after (2023-2024). In states the place that information weren’t obtainable, researchers analyzed probably the most comparable information as an alternative.

Of the two,066 counties in 33 states that researchers analyzed, 78% of them reported a decline in vaccination charges. Researchers discovered that the county-level imply vaccination charge decreased from nearly 94% earlier than the pandemic to about 91% after the pandemic—falling properly beneath what public-health experts generally consider to be the brink for herd immunity in opposition to measles of about 95%.

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Lauren Gardner, senior writer of the research and director of Johns Hopkins College’s Middle for Programs Science and Engineering, says the objective of this analysis was to get a “extra complete, increased decision understanding of the vaccination panorama” within the nation.

The U.S. Facilities for Illness Management and Prevention (CDC) “has national- and state-level information, however we all know that vaccination patterns can differ considerably inside a state and even at a better decision than that throughout communities, inside even the county,” Gardner says. For locations with a low vaccination charge, “if measles will get launched into these areas, there’s extra prone to be an outbreak. And that’s what we’re seeing.”

As of Might 29, a complete of 1,088 confirmed measles instances have been reported by 33 jurisdictions within the U.S., according to the CDC. Of these instances, 96% have been in individuals who have been both unvaccinated or whose vaccination standing was unknown. Thus far in 2025, there have been 14 reported outbreaks and three individuals confirmed to have died of measles-related problems, all of whom have been unvaccinated. Earlier than this 12 months, the final confirmed measles-related demise within the nation occurred in 2015.

Getting vaccinated is one of the simplest ways to be protected in opposition to measles. The MMR vaccine is each secure and efficient, and the CDC has said that most individuals who get it will likely be protected in opposition to measles for all times.

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The brand new research discovered that solely 4 of the 33 states that researchers analyzed—California, Connecticut, Maine, and New York—reported an increase within the median county-level vaccination charges. Researchers didn’t examine the causes behind disparate charges, and Gardner says that many components—together with the pandemic’s affect on entry to well being care, completely different populations, the standard of reported information, and vaccine hesitancy—play a job in a neighborhood’s vaccination charges. However she additionally notes that the 4 states that reported a rise within the measles vaccination charge are among the many few that don’t allow non-medical exemptions for varsity immunization necessities, such because the MMR vaccine.