The number of children in the United States skipping routine vaccinations is increasing, creating larger vulnerable populations and heightening the risk of outbreaks of preventable diseases such as measles, which is currently spreading at record levels in some regions.
New research published in the medical journal JAMA indicates that exemptions from school-required vaccines have climbed in more than half of U.S. counties since the start of the COVID-19 pandemic. Most of these exemptions are nonmedical, citing personal or religious beliefs, while medical exemptions — for children with compromised immune systems or severe allergies — have remained largely unchanged.
“The science confirming the safety and effectiveness of vaccines has not changed,” said Dr. Jesse Hackell, a pediatrician and lead author of an American Academy of Pediatrics policy statement advocating for the elimination of nonmedical exemptions. “What has shifted is the spread of misinformation and the politicization of vaccines, not the evidence showing they prevent illness and save lives.”
Understanding the Scope of the Trend
Researchers analyzed county-level data on kindergarten vaccination exemptions before and after the pandemic, finding a median increase in nonmedical exemptions from 0.6% in 2010-2011 to over 3% in 2023-2024. More than half of U.S. counties saw exemptions rise by at least one percentage point, while around 5% of counties recorded increases of five points or more.
According to the CDC, this trend is likely linked to rising vaccine hesitancy. While most parents support mandatory school vaccinations, surveys indicate that philosophical or personal belief objections account for over a third of exemption requests. Other reasons include difficulty meeting school deadlines and, in some cases, perceived medical concerns about vaccine safety or side effects.
Dr. Nathan Lo, an infectious disease expert at Stanford University, emphasized that small gaps in coverage can have outsized effects. “National or state averages can be misleading because they mask pockets of low vaccination that drive outbreaks,” Lo said.
Outbreaks Highlight the Dangers of Low Coverage
Spartanburg County in South Carolina illustrates the consequences of declining vaccination rates. Nearly 8% of children there held nonmedical exemptions in 2024, up from 2% a decade ago. The county is at the center of a rapidly expanding measles outbreak, now exceeding 400 confirmed cases, with hundreds more quarantined after exposure. Public places, schools, and holiday gatherings have all contributed to the disease’s spread.
“These under-vaccinated areas are highly interconnected,” Lo explained. “When local exemption rates rise, it doesn’t just affect one county — neighboring regions can see increases in cases as well.”
Most of the current measles cases have been among children who were not immunized with the MMR vaccine. Health experts warn that localized clusters of unvaccinated children can lead to broader outbreaks that threaten the wider community. Cases linked to travel from South Carolina have already been reported in North Carolina and New Mexico.
The Role of Policy and Public Messaging
Some states, including California, Connecticut, Maine, and New York, have eliminated nonmedical exemptions, resulting in improved vaccination coverage. In contrast, states like Florida are moving toward ending school vaccine mandates entirely, potentially increasing risk in the future.
Experts stress that legislation remains the most effective tool for boosting vaccination rates. However, consistent conversations between parents and healthcare providers, alongside clear public health messaging, are also essential.
“The overwhelming majority of parents choose to vaccinate,” Hackell said. “Immunization is the social norm, protecting both individual children and the wider community. Upholding that norm reflects science and safeguards public health.”
National data for the 2024-2025 school year shows that over 96% of kindergartners were vaccinated, though rising exemptions highlight the importance of monitoring local trends and addressing pockets of under-vaccination before outbreaks worsen.
