Lead
Since the start of the Covid-19 pandemic, nonmedical exemptions from school-required vaccines have grown across many US counties, leaving larger local populations vulnerable to preventable illnesses such as measles. New county-level research published in JAMA finds the median nonmedical exemption rate rose from about 0.6% in 2010–2011 to over 3% in 2023–2024, while medical exemptions stayed stable. Public-health officials link the change primarily to philosophical or religious objections and to increasing vaccine hesitancy. Those local gaps are already associated with fast-moving outbreaks, most notably a large measles cluster centered in Spartanburg County, South Carolina.
Key Takeaways
- Median nonmedical exemption rate rose from ~0.6% (2010–2011) to >3% (2023–2024) across analyzed counties, per a JAMA analysis.
- About 53.5% of US counties saw nonmedical exemption rates increase by at least 1% comparing 2010–2020 vs. 2021–2024.
- Roughly 5% of counties—about 1 in 20—saw nonmedical exemptions climb by 5 percentage points or more in that interval.
- Spartanburg County’s nonmedical exemption rate climbed from 2% in 2014 to nearly 8% in 2024; the county is the center of a rapidly expanding measles outbreak now exceeding 400 cases.
- In the current South Carolina outbreak, 92% of cases are children and nearly all cases are unvaccinated for MMR.
- Federal data show 3.6% of kindergartners in 2024–25 had an exemption for a required vaccine, implying over 96% were vaccinated nationally.
- States that have removed nonmedical exemptions (California, Connecticut, Maine, New York) saw exemption declines, while Florida recently ended school vaccine mandates.
Background
School-entry vaccine requirements have long been a cornerstone of US public-health strategy to prevent outbreaks of measles, mumps, rubella and other childhood diseases. Most states allow medical exemptions and many have permitted nonmedical exemptions for religious or philosophical reasons. Before the Covid-19 pandemic, nonmedical exemption rates were low in most places, but the pandemic coincided with rising hesitancy and intensified misinformation campaigns in some communities.
Public-health authorities warn that even modest local declines in vaccine coverage can undermine herd immunity for highly contagious diseases like measles, which requires about 95% coverage to prevent sustained transmission. Localized clusters of undervaccination concentrate susceptible people geographically and socially—through schools, religious congregations, and social networks—making outbreaks more likely to begin and spread. Policymakers and clinicians have responded unevenly: some states have tightened laws to eliminate nonmedical exemptions, while others have moved to relax mandates.
Main Event
Researchers compared county-level kindergarten exemption averages from a pre-pandemic baseline to the most recent years and included nearly 90% of US counties with sufficient data. Their analysis shows a clear upward shift in nonmedical exemptions in more than half of counties, while medical exemptions did not show the same increase. The result points to changing social and political dynamics rather than changes in clinical eligibility for exemptions.
Spartanburg County, South Carolina, exemplifies the local risks. The county’s nonmedical exemption rate was about 2% in 2014 and rose to nearly 8% in 2024—coinciding with an outbreak that state officials say has now surpassed 400 confirmed measles cases and continues to expand. Public exposures have been reported at schools, churches and public attractions, and hundreds of contacts remain in quarantine after unprotected exposures.
Health departments and researchers trace recent spread to intercounty travel and social mixing during holidays, when school breaks and family gatherings increase contact across communities. Officials report multiple linked cases in neighboring states—some tied to travel to Spartanburg—demonstrating how an under-immunized pocket can seed cases well beyond its borders.
Analysis & Implications
The rise in nonmedical exemptions is primarily a social and political phenomenon rather than a clinical one. Pediatric and public-health experts note that the underlying science on vaccine safety and efficacy has not changed; instead, the drivers are growing vaccine hesitancy, mis- and disinformation, and, in some places, political shifts that reduce institutional barriers to exemptions. That combination has expanded the size and number of vulnerable pockets.
Even small drops in coverage can have outsized local effects for measles because of its high transmissibility. A county-level change of a few percentage points can move a community from robust herd protection to one capable of sustaining localized epidemics. Those local epidemics then increase risk in adjoining counties through normal travel and social ties, meaning outbreaks are not confined to the lowest-coverage areas.
Policy responses diverge: elimination of nonmedical exemptions through state law has shown the most consistent large-scale effect on coverage, according to experts. However, laws are politically contentious and take time to pass and implement. In practice, clinicians and public-health communicators emphasize one-on-one conversations between clinicians and families and steady, accurate public messaging as essential to reversing trends in many communities.
Comparison & Data
| Measure | 2010–2011 | 2023–2024 |
|---|---|---|
| Median nonmedical exemption (kindergarten) | ~0.6% | >3% |
| Counties with ≥1% increase | — | 53.5% of counties |
| Counties with ≥5% increase | — | ~5% of counties (~1 in 20) |
| Spartanburg County nonmedical exemptions | 2% (2014) | ~8% (2024) |
The table summarizes the principal quantitative findings from the JAMA analysis and local health reports. Those numbers show a shift in the distribution of exemptions: most counties remain highly vaccinated, but the risk is concentrated in growing pockets where exemption rates are substantially higher than state or national averages. That concentration explains why national figures can mask fast local vulnerability.
Reactions & Quotes
“The science behind immunizations has not changed in the past five years,” said Dr. Jesse Hackell, urging removal of nonmedical school-entry exemptions to protect community health.
Dr. Jesse Hackell, pediatrician and AAP policy lead
“Small differences in coverage matter greatly at the local level; pockets of low vaccination drive outbreaks,” said Dr. Nathan Lo, lead author of the county-level study.
Dr. Nathan Lo, infectious disease physician and study author (Stanford)
State health officials in South Carolina warned that holiday travel and gatherings have amplified spread and that exposures have been reported at schools, museums and churches.
South Carolina Department of Health and Environmental Control (state health agency)
Unconfirmed
- Precise causal weight of misinformation versus logistical barriers (e.g., access to clinics) in every county is not yet fully determined; county-level drivers vary.
- Some parental reports classified as “medical reasons” in surveys may reflect safety concerns rather than documented clinical contraindications; the extent of misclassification is not fully quantified.
- Future case counts tied to currently quarantined contacts in South Carolina are expected to rise, but the final total and outbreak duration remain uncertain.
Bottom Line
County-level data show that nonmedical vaccine exemptions have increased in many US communities since the pandemic, producing larger and more numerous pockets of vulnerability that can spark localized epidemics of measles and other vaccine-preventable diseases. National and state averages obscure these local risks, which are the immediate drivers of outbreaks.
Policy interventions that remove nonmedical exemptions have reduced exemptions where enacted, but legislative change is neither universally accepted nor rapidly implemented. In the near term, reversing trends in high-exemption counties will depend on targeted outreach, clinician-family conversations, and sustained, evidence-based public messaging to rebuild trust and close local immunity gaps.
Sources
- CNN (news report summarizing JAMA study and state health data)
- JAMA Network (peer-reviewed medical journal; original county-level analysis cited)
- Centers for Disease Control and Prevention (CDC) (federal public-health agency; vaccination and survey data)
- South Carolina Department of Health and Environmental Control (state health agency) (outbreak updates and case counts)
- American Academy of Pediatrics (professional association) (policy statement on nonmedical exemptions)