Measles Shield Frays: Most U.S. Counties Fall Below Kindergarten Vaccination Target

In a small Minnesota town that once boasted near-perfect vaccination rates, the kindergarten roster now tells a different story.

At Becker Primary School, northwest of Minneapolis, nearly every child used to arrive for the first day of class protected against measles. This school year, only 77% of kindergarteners there are vaccinated with the measles, mumps and rubella shot, according to school and state data — well below the 95% level public health officials say is needed to keep the highly contagious virus from spreading.

Multiplied across thousands of schools, that quiet drop has pushed much of the country below the threshold long considered the safety net for children too young or too sick to be vaccinated.

A national slide below the herd-immunity line

Newly compiled data show that only about 28% of U.S. counties now meet the 95% measles vaccination benchmark among kindergarteners, down from about half of counties before the COVID-19 pandemic. At least 5.2 million kindergarten-age children live in counties where classroom coverage falls short of that line, as measles cases climb to their highest levels in more than 30 years.

The shift comes as nonmedical exemptions reach record highs, school districts scale back enforcement of vaccine rules and state legislatures move to loosen long-standing requirements — even while federal officials warn the United States is at risk of losing its measles “elimination” status.

Measles cases surge as coverage slips

Measles, once declared eliminated in the country in 2000, has surged back in recent years. Health officials reported roughly 2,000 cases nationwide in 2025, compared with 285 in all of 2024 and 1,274 in 2019, the previous recent peak. The Centers for Disease Control and Prevention has said more than 90% of infections in recent U.S. outbreaks have been in people who were unvaccinated or whose vaccination status was unknown.

At least three people, including two unvaccinated children in Texas, died of measles in 2025, according to state and federal health reports.

Nationally, two-dose MMR coverage among kindergarteners has slid from about 95% in the 2019–20 school year to roughly 92.5% in 2024–25. That may sound like a small decline, but measles is among the most contagious viruses known; one infected person can spread it to 12 to 18 others in a susceptible population. Because of that, health authorities have long set a higher target — about 95% coverage — to prevent sustained transmission.

Even that target may be fragile. Some modeling studies suggest closer to 97% coverage could be needed to reliably block outbreaks in dense or highly connected communities.

A patchwork driven by laws, exemptions and enforcement

Where those numbers fall — and why — increasingly depends on where a child lives.

In California, which in recent years eliminated both religious and personal-belief exemptions and allows only medical exemptions for school-required vaccines, kindergarten measles coverage is about 96%. But in Idaho, Louisiana, Oregon, Tennessee, Utah and Wisconsin, recent data show no counties where coverage among kindergarteners reaches 95%.

In Ouachita Parish, Louisiana, roughly a quarter of kindergarteners lack measles vaccination. In the city of St. Louis, the share of vaccinated kindergarteners is about 74%. In Detroit, coverage dropped from about 94% before the pandemic to 84% in recent data; in Chicago, it fell from roughly 92% to 86%.

The steepest declines tend to appear in states that allow nonmedical exemptions for religious or personal beliefs. In the five states that do not allow any nonmedical exemptions, average kindergarten measles coverage has ticked up slightly since the pandemic, by about 1.2 percentage points. In states that do allow such exemptions, coverage has fallen about 3 points on average, and in those with broad personal-belief exemptions the drop is larger still.

At the same time, the share of kindergarteners formally exempted from at least one vaccine has climbed to 3.6%, according to CDC estimates for the 2024–25 school year — the highest on record. More than 93% of those exemptions are nonmedical. Seventeen states now report exemption rates above 5%.

“It’s increasingly the case that we have very different levels of health and protection based on ZIP codes, and children don’t get to choose where they live or where they go to school,” said Dr. Susan Kressly, president of the American Academy of Pediatrics. “Immunization is a child health priority, not a partisan issue.”

Politics and identity shape parental choices

Yet the pattern has become deeply entangled with politics and identity.

An analysis of recent data found that counties carried by former President Donald Trump in the 2024 election were more likely to experience steep drops in kindergarten vaccination than those won by then-Vice President Kamala Harris. Surveys conducted in tandem with that analysis found that parents who delay or decline vaccines are more likely to identify as Republican, to be white and very religious, to be under 35 and to home-school their children.

“People want to take a stand against government, against politicians, against people in power, and exemptions for vaccines is one of the easier ways to do so,” said Lauren Atkinson, a parent in Becker, Minnesota, who was interviewed about declining vaccination rates in her district.

Federal messaging under scrutiny

The Trump administration’s health leadership has added another layer of complexity. Health and Human Services Secretary Robert F. Kennedy Jr., a longtime critic of vaccine mandates, has moved to reshape federal vaccine policy since taking office. Under his direction, the government has overhauled its vaccine advisory committee and backed a December 2025 vote to drop the long-standing recommendation that all newborns receive a hepatitis B shot.

Kennedy has also pushed for changes in how federal agencies discuss vaccine safety. Some pediatricians say new phrasing on federal websites has softened or muddied previous statements that vaccines do not cause autism, despite extensive scientific evidence.

Dr. Leslie King-Schultz, a pediatrician in Minneapolis, said the changes “leave parents very confused about who they should trust and what information they should rely on,” which she believes increases the odds some families skip routine shots.

An HHS spokesman, Andrew Nixon, said Kennedy “has been clear that vaccination is the most effective way to prevent measles,” while reiterating the secretary’s opposition to school mandates and support for parental choice.

Schools weigh public health against pressure to keep kids in class

On the ground, school districts are caught between public health guidance and community pressure.

In Minnesota, about one-third of schools that responded to a 2023 state survey reported having no policy to refuse entry to students lacking immunization records. Some administrators said they had stopped strictly enforcing vaccine rules to avoid confrontations after COVID-19 and to keep attendance up.

“We don’t promote medical decisions,” Becker Public Schools Superintendent Jeremy Schmidt said, explaining that getting children back into classrooms became the top priority once schools fully reopened.

Across 31 states, CDC figures show that about 2.6% of kindergarteners attend school in “grace periods” or on provisional enrollment — children who are not up to date on vaccinations and do not have exemptions, but are allowed in class while they catch up. Public health officials say those groups, combined with exempt students, can leave communities far more vulnerable than overall averages suggest.

Outbreaks disrupt classrooms — and can have lasting health effects

The consequences have already been felt in classrooms.

In South Carolina, a measles outbreak in late 2025 grew to more than 175 cases, mostly among unvaccinated people, leading to hundreds of students being quarantined. Former U.S. Surgeon General Jerome Adams pointed to the episode as evidence that loosening school vaccine requirements does not guarantee students will spend more days in class; unvaccinated children were instead ordered to stay home for weeks.

Measles infection can cause pneumonia, brain swelling and, in rare cases, death. Research over the past decade has also shown that the virus can wipe out much of a child’s existing immune memory — a phenomenon known as “immune amnesia” — leaving them more susceptible to other diseases for months or years after they recover.

Risk to measles “elimination” status

The United States came close to losing its measles elimination status in 2019, when outbreaks linked to under-vaccinated communities in New York and elsewhere dragged on for months. The designation, maintained by the World Health Organization and national health agencies, signifies that a country has no continuous measles transmission for at least 12 months in the presence of strong surveillance. Health experts now warn that interconnected outbreaks beginning in West Texas in early 2025 and spreading to other states could cross that threshold.

Unlike in the early 1990s — when a resurgence of more than 55,000 measles cases and 123 deaths spurred the country to add a second routine MMR dose and strengthen school enforcement — today’s resurgence is unfolding amid a broader rollback of vaccine rules in many legislatures.

One factor remains unchanged: the virus. Measles spreads the same way it did when school mandates were first adopted in the 19th and 20th centuries — through shared air, often before symptoms appear.

What has shifted is the reliability of the protections that once surrounded most American children when they entered kindergarten. In some states, data suggest that tighter laws and clear messaging can still push coverage above herd-immunity levels. Elsewhere, decisions in statehouses, school offices and federal agencies are producing a patchwork in which the likelihood of encountering measles in a classroom depends heavily on which side of a county or state line a child happens to live.

As parents log on to new public databases that show coverage at their neighborhood school, many are confronting numbers they never thought to question.

For families of infants too young for full vaccination — or of children with leukemia or other conditions that prevent them from being immunized — the stakes in those figures are immediate. Their safety rests not just on their own choices but on the decisions of neighbors, classmates and officials, and on whether the country chooses to rebuild the wall of immunity that is now visibly full of gaps.