New data shows that more than 75% of US counties have widespread vaccination coverage, with many people not exempt from the outbreak.
New county-level data compiled from state health agencies shows that measles cases are surged while vaccination compensation is eroding across the US.
The outbreak of measles has infected more people than any other year since the early 1990s, and has already killed three people. So far, all but eight states have reported cases of measles, and the disease declared by the US in 2000 was eliminated in 2000. Almost 92% of these cases are either unvaccinated or have no vaccination status.
Federal data released in July showed that while the share of children exempted for religious and philosophical reasons has increased, many years of stable childhood vaccination rates have declined.
“What we’re seeing is that when trust is eroding as vaccination rates drop, it’s a measles outbreak,” said Adam Ratner, a member of the American Academy of Pediatrics’ Committee on Infectious Diseases.
Ratner said the outbreak should act as a public health warning system, indicating that other diseases could continue.
“You have to look beyond that because diseases that are preventable with vaccines but are a little less contagious than measles are what you see afterwards,” he said.
To assess coverage at the local level, Johns Hopkins University has compiled data from state health agencies that reveal how vulnerable the vulnerable communities in which communities are generated are, if there is no federal database. USA Today expanded the effort by adding missing state data from the university’s database to fill the gap.
An analysis of this combined data covering counties in 41 states showed that the range of routine vaccines among children has slipped down in most counties, indicating that more communities are becoming more vulnerable than before the pandemic.
In at least three of the four counties, vaccinations range less than 95%.
“The fact that there are so many counties under this threshold means there is a lot of exposure risk,” said Lauren Gardner, director of the Center for Systems Science and Engineering at Johns Hopkins University.
“That definitely doesn’t mean there’s an outbreak, but if a case is introduced in the community, it’s a higher risk,” she added.
Experts also warn that if compensation falls below 90%, the risk of occurrence will rise sharply. They say that children with immunocompromised and too young to be vaccinated are dependent on the immunity of the community.
Today, about 63% of the county meet that minimum threshold, compared to 84% before the pandemic.
The data, along with interviews with public health experts, highlights that skepticism about the Covid-19 vaccine has permeated a wider attitude towards vaccination, exacerbated by the spread of misinformation and disinformation.
Vaccine skeptics have falsely argued that the measles vaccine is causing autism. This has been repeatedly disproved by extensive scientific research. Anyway, rising vaccine skepticism has discouraged parents from vaccinating their children from dangerous diseases.
A survey by the Kaiser Family Foundation – Washington Post in September found that 9% of parents believed in false claims that linked the MMR vaccine to autism, and almost half didn’t know what to believe. About one in six parents reported delays or skipping of vaccines (excluding seasonal flu and Covid-19).
Parents who identify Republicans, young or homeschooling as their children are most likely to delay or skip the vaccine.
The Centers for Disease Control and Prevention recommends administering two doses of the MMR vaccine for children. The first is 12-15 months, then 4-6 years. The agency also recommends vaccines for polio, chicken pox and hepatitis B, viral infections that affect the liver.
Public health experts say these recommendations face challenges under outspoken vaccine critic, Health Secretary Robert F. Kennedy Jr. Kennedy fired all 17 members of the CDC Advisory Committee on Vaccination Practices (ACIP) in June, replacing some with vaccine skeptics.
ACIP has already rescheduled the MMRV (measles, mumps, rubella, water cell) vaccine and has removed recommendations for children under the age of 4. The committee also considered changing the recommendations for hepatitis B, but the vote was delayed.
Experts warn that these changes could increase disruption and further erode vaccination rates, despite the continued importance of vaccine safety and clarity of access.
To that end, granularity data collected by Johns Hopkins University and USA Today is important to identify vulnerable populations, Ratner said.
“A lot of times people look at the prices in the state, but that’s important,” Ratner said. “But what we really found is that what’s important is either at the county level or even smaller.”
Data from Johns Hopkins University-USA Today is based on county-level vaccinations among kindergarteners, and in some cases cover all doses required by K-6 or K-12 students to receive an MMR vaccination or school admission.
There is a warning. Record collections vary depending on the state, so you need to carefully compare state by state. Because some agencies track compliance with vaccine requirements rather than actual vaccination status, real vaccination rates could be lower than reported in these cases.
For example, Oregon excludes exempt students by completion rate, but Wisconsin does not.
“We’re a great place to go,” said Jennifer Miller, a spokesman for Wisconsin Health Services.
Measles once made millions of Americans sick and killed hundreds each year. In the 1960s, the United States launched a vaccination program, eventually eradicating measles just before the turn of the century. By 1980, all 50 states had adopted school vaccine missions and requested that children be vaccinated before registration.
Measles is particularly dangerous as it can spread before symptoms appear. Even with low mortality, the virus can cause permanent complications such as brain damage, neurological problems, and blindness.
As of September 30th this year, the US had reported approximately 1,550 measles cases, exceeding the total since the early 1990s. Only 2019 is approaching when the disease spreads to unvaccinated communities in New York.
The first outbreak of 2025 occurred in the Mennonite community in Gaines County, Texas, where vaccination rates are low. The virus then spread to West Texas, New Mexico and Oklahoma. Gaines County has reported nearly a quarter of the national total this year.
So, vaccinations for kindergarteners have averaged around 82.4% in recent years, down 12.6 points below the 12.6 points that experts call community immunity.
Prior to the Covid-19 pandemic, 57% of the county were considered fully protected from outbreaks. That figure has since dropped to 25%.
The decline in coverage spans nearly three-quarters of the county, each experiencing an average of four points decline. Only two states, Connecticut and Maryland, have all counties above the immunity threshold, while nine counties in 10 in Maine and New York have met. No counties remove bars in Alaska, Hawaii, Idaho, Utah, or Wisconsin. It is the same state where the exemption rate is high.
In July, the CDC estimated there was a lack of evidence that 286,000 kindergarteners would complete the MMR vaccine series between 2024 and 25.
Meanwhile, medical exemptions remain flat, but more parents are exempting their children from vaccination on religious or philosophical grounds. The non-medical exemption rate rose from 2024 to 2025 from 2% a decade ago to 3.4%.
Elizabeth Williams, senior policy manager for Medicaid and uninsured programs at the Kaiser Family Foundation, could have a major impact even with a small increase.
“All increases reduce the ability of scientists to reach thresholds they believe will protect their communities,” Williams said.
Experts recommend keeping the exemption rate below 5%, but 17 states have surpassed that level. Idaho leads at 15%, followed by Utah and Oregon at 10% respectively, while Arizona and Alaska at 9%.
“There is concern about rising exemption rates, especially when children who are exempt from schools work under the assumption that they are not vaccinated,” said AJ McWhorter, a spokesman for the Idaho Department of Health and Human Services.
“While a vaccine-preventable disease outbreak, there will be more children at risk of getting sick and likely need to be excluded from school,” McWhorter said.
Policy shifts could further reduce vaccination rates. Many states have introduced changes that make it easier for families to make exemptions easier. Florida plans to remove the mandate from public schools entirely.
Since 2021, lawmakers across the country have introduced over 2,500 vaccine-related bills, and almost half of the targeting requirements, including mission and school exemptions.
These state-level changes will exacerbate the situation by continuing misinformation and access challenges, along with changing federal guidance, an epidemiologist with the Oregon Department of Health said in an email.
Public health is the responsibility of the community, said Gardner, a Johns Hopkins expert. “Everyone has to get involved in it because otherwise it won’t actually work.”
