Even small drops in vaccination rates for US children can lead to disease outbreaks
- Vaccination rates among US children have declined by more than three-quarters of counties and jurisdictions since 2019, leading to a “large swath” of the country lacking basic immunity against diseases like measles.
- The decline in vaccination rates is concerning because it can lead to outbreaks of infectious diseases, even if the national vaccination rate appears high. Local community levels are particularly vulnerable to outbreaks when vaccination rates fall below state averages.
- Non-medical vaccine exemptions, often based on religious or philosophical reasons, have increased from 1-2% in previous years to 3.6% in the 2024-25 school year, posing a risk to herd immunity and community health.
- Parents’ concerns about vaccines are often fueled by misinformation spread through social media and growing partisanship around vaccines. However, vaccines have been proven safe and effective in preventing diseases like polio, which are no longer routinely seen due to widespread vaccination efforts.
- As a pediatrician, Dr. David Higgins advises parents to keep their children up-to-date on required vaccines, follow state requirements, and practice good hygiene habits like handwashing and staying home when sick to protect their child’s health and contribute to herd immunity.
More than three-quarters of U.S. counties and jurisdictions are experiencing declines in childhood vaccination rates, a trend that began in 2019, according to a September 2025 NBC NewsâStanford University investigation. The report also found a âlarge swathâ of the U.S. no longer has the âbasic, ground-level immunityâ needed to stop the spread of measles.
Dr. David Higgins, an assistant professor of pediatrics at the University of Colorado CU Anschutz Medical Center and a pediatrician who researches vaccines, discusses the dangers of not vaccinating your children.
The Conversation has collaborated with SciLine to bring you highlights from the discussion, edited for brevity and clarity.
What vaccines are typically required for schoolchildren, and why?
David Higgins: The vaccine requirements for kids to attend school are set by states, not the federal government. Most states require kindergartners get vaccines for pertussis â thatâs whooping cough â and tetanus, measles, mumps, rubella and chickenpox.
For older kids, a booster of the tetanus and pertussis vaccine is typically required, as well as a vaccine for meningococcal disease.
Vaccines reduce the risk of outbreaks in places where transmission of these diseases is easy. Not only do vaccinations help keep both students and teachers safe, it also encourages overall higher community coverage for these vaccines.
How do scientists track the safety of vaccines over time?
Higgins: Before vaccines are approved, they undergo rigorous trials. During this process, scientists look at the safety and effectiveness of the vaccine, testing it first in small groups to assess safety, then in larger groups to confirm protection and detect uncommon side effects. That process continues after the vaccine is approved. Those systems continually monitor the safety of vaccines, both here in the U.S. as well as around the world.
What are the vaccination coverage trends for kindergartners?
Higgins: What we have seen is a small downward trend since 2019, the year prior to the COVID-19 pandemic. It slipped from 95% of new kindergartners being up to date on many of their routine vaccines to about 92%.
Thatâs a small percentage decrease, so a great majority of parents are still vaccinating their kids. But at the same time, anything below our target of 95% for diseases like measles becomes a problem, because thatâs below the level thatâs needed for what we call herd immunity, or community immunity. When that happens, itâs not a matter of if, but when, we see an outbreak of these infectious diseases.
And while nationwide rates are important to look at, outbreaks happen at local community levels. For example, earlier this year, an outbreak of measles in West Texas spread rapidly through communities where vaccination rates had slipped well below the state average.
So, the vaccination rate at your own school or community is much more meaningful than what the national vaccination rate is.
How do non-medical vaccine exemptions work?
Higgins: First, actual medical exemptions are rare, and these occur when the vaccine is unsafe for the child to receive, like when he or she has a known severe allergic reaction to vaccine ingredients.
Non-medical exemptions for vaccines are often for religious, personal or philosophical reasons. They have been increasing for the past several years, rising from the range of 1 to 2% up to 3.6% in the 2024â25 school year. Thatâs a small increase, but again, itâs still concerning.
Why are some parents vaccine hesitant?
Higgins: There are multiple reasons. These include misinformation which algorithm-driven echo chambers on social media can spread at an alarming rate right now. Also, Americans report less trust in institutions and experts, and studies have found growing partisanship around vaccines.
Additionally, vaccines are victims of their own success. They have worked so well that many diseases like polio arenât routinely seen anymore. That might lead a parent to think the risk for their child is so low that the vaccine is not necessary. But the fact is, vaccines are simply holding these diseases at bay. And as vaccination rates drop, these diseases will come back and more kids will be at risk.
What advice do you have for parents?
Higgins: The most important thing you can do as a parent is to keep your kids up to date on required vaccines. That includes the annual flu shot. Follow your stateâs requirements and current recommendations from trusted sources like the American Academy of Pediatrics and your own personal pediatrician to know which vaccines your child should have.
You also want to reinforce other common sense approaches to keeping your children healthy. Make sure they know how to wash their hands properly and that they stay home when theyâre sick. Teach them to sneeze and cough into their elbow instead of into their hands â even though doing so isnât a perfect solution.
As a pediatrician, I love when my families come and talk to me about their concerns. I help them walk through their worries so they can feel more confident that theyâre making a truly informed decision thatâs in the best interest of their childâs health.
SciLine is a free service based at the American Association for the Advancement of Science, a nonprofit that helps journalists include scientific evidence and experts in their news stories.
David Higgins is a member of the American Academy of Pediatrics. He is also on the board of directors (volunteer) for Immunize Colorado.